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Groups > linux.kernel > #1523884 > unrolled thread
| Started by | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| First post | 2016-11-16 23:30 +0100 |
| Last post | 2016-11-16 23:50 +0100 |
| Articles | 20 on this page of 66 — 4 participants |
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[PATCH 00/29] Improve radix tree for 4.10 Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 06/29] radix tree test suite: benchmark for iterator Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 07/29] radix tree test suite: Use rcu_barrier Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 24/29] tpm: Use idr_find(), not idr_find_slowpath() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 01/29] tools: Add WARN_ON_ONCE Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 06/29] radix tree test suite: benchmark for iterator Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 20/29] radix tree: Improve multiorder iterators Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 12/29] radix-tree: Add radix_tree_split_preload() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 19/29] radix tree test suite: iteration test misuses RCU Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 18/29] btrfs: Fix race in btrfs_free_dummy_fs_info() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 10/29] radix-tree: Add radix_tree_join Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 23/29] idr: Add ida_is_empty Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 22/29] radix-tree: Delete radix_tree_range_tag_if_tagged() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 25/29] rxrpc: Abstract away knowledge of IDR internals Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 05/29] radix tree test suite: Make runs more reproducible Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 14/29] radix-tree: Move rcu_head into a union with private_list Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 15/29] radix-tree: Create node_tag_set() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 27/29] radix tree test suite: Add some more functionality Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:30 +0100
[PATCH 08/29] tools: Add more bitmap functions Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 21/29] radix-tree: Delete radix_tree_locate_item() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
Re: [PATCH 21/29] radix-tree: Delete radix_tree_locate_item() Konstantin Khlebnikov <koct9i@gmail.com> - 2016-11-18 13:00 +0100
RE: [PATCH 21/29] radix-tree: Delete radix_tree_locate_item() Matthew Wilcox <mawilcox@microsoft.com> - 2016-11-18 17:50 +0100
[PATCH 11/29] radix-tree: Add radix_tree_split Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 08/29] tools: Add more bitmap functions Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 07/29] radix tree test suite: Use rcu_barrier Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 28/29] radix-tree: Create all_tag_set Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 10/29] radix-tree: Add radix_tree_join Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 17/29] radix-tree: Improve dump output Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 14/29] radix-tree: Move rcu_head into a union with private_list Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 02/29] radix tree test suite: Allow GFP_ATOMIC allocations to fail Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 25/29] rxrpc: Abstract away knowledge of IDR internals Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 02/29] radix tree test suite: Allow GFP_ATOMIC allocations to fail Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 18/29] btrfs: Fix race in btrfs_free_dummy_fs_info() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 23/29] idr: Add ida_is_empty Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
Re: [PATCH 23/29] idr: Add ida_is_empty Konstantin Khlebnikov <koct9i@gmail.com> - 2016-11-18 13:00 +0100
[PATCH 16/29] radix-tree: Make radix_tree_find_next_bit more useful Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 20/29] radix tree: Improve multiorder iterators Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
Re: [PATCH 20/29] radix tree: Improve multiorder iterators Konstantin Khlebnikov <koct9i@gmail.com> - 2016-11-18 12:50 +0100
RE: [PATCH 20/29] radix tree: Improve multiorder iterators Matthew Wilcox <mawilcox@microsoft.com> - 2016-11-18 17:40 +0100
Re: [PATCH 20/29] radix tree: Improve multiorder iterators Konstantin Khlebnikov <koct9i@gmail.com> - 2016-11-18 19:00 +0100
RE: [PATCH 20/29] radix tree: Improve multiorder iterators Matthew Wilcox <mawilcox@microsoft.com> - 2016-11-18 22:00 +0100
[PATCH 17/29] radix-tree: Improve dump output Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 04/29] radix tree test suite: Free preallocated nodes Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 09/29] radix tree test suite: Use common find-bit code Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 22/29] radix-tree: Delete radix_tree_range_tag_if_tagged() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 13/29] radix-tree: Fix typo Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 24/29] tpm: Use idr_find(), not idr_find_slowpath() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 04/29] radix tree test suite: Free preallocated nodes Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 21/29] radix-tree: Delete radix_tree_locate_item() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 26/29] idr: Reduce the number of bits per level from 8 to 6 Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 26/29] idr: Reduce the number of bits per level from 8 to 6 Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:40 +0100
[PATCH 28/29] radix-tree: Create all_tag_set Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
[PATCH 16/29] radix-tree: Make radix_tree_find_next_bit more useful Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
[PATCH 05/29] radix tree test suite: Make runs more reproducible Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
[PATCH 03/29] radix tree test suite: Track preempt_count Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
[PATCH 09/29] radix tree test suite: Use common find-bit code Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
[PATCH 27/29] radix tree test suite: Add some more functionality Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
[PATCH 12/29] radix-tree: Add radix_tree_split_preload() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
[PATCH 01/29] tools: Add WARN_ON_ONCE Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
[PATCH 15/29] radix-tree: Create node_tag_set() Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
[PATCH 11/29] radix-tree: Add radix_tree_split Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
[PATCH 00/29] Improve radix tree for 4.10 Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
RE: [PATCH 00/29] Improve radix tree for 4.10 Matthew Wilcox <mawilcox@microsoft.com> - 2016-11-17 21:00 +0100
Re: [PATCH 00/29] Improve radix tree for 4.10 Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-11-17 23:20 +0100
RE: [PATCH 00/29] Improve radix tree for 4.10 Matthew Wilcox <mawilcox@microsoft.com> - 2016-11-18 05:40 +0100
[PATCH 19/29] radix tree test suite: iteration test misuses RCU Matthew Wilcox <mawilcox@linuxonhyperv.com> - 2016-11-16 23:50 +0100
Page 1 of 4 [1] 2 3 4 Next page →
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 00/29] Improve radix tree for 4.10 |
| Message-ID | <sEgSl-rg-1@gated-at.bofh.it> |
From: Matthew Wilcox <mawilcox@microsoft.com> Hi Andrew, Please include these patches in the -mm tree for 4.10. Mostly these are improvements; the only bug fixes in here relate to multiorder entries (which as far as I'm aware remain unused). The IDR rewrite has the highest potential for causing mayhem as the test suite is quite spartan. We have an Outreachy intern scheduled to work on the test suite for the 2016 winter season, so hopefully it will improve soon. I posted a series of patches to improve the radix tree code two months ago, and Konstantin had the quite reasonable objection that they slowed down the iterators. He helpfully sent out the benchmark he used. With this revision of the patchset, I have slightly improved performance on his benchmark. Noteworthy changes from the last revision of the patchset: - Fix the existing radix tree iterator design instead of rewriting it - Avoid adding the new radix_tree_for_each_tagged_max iterator; just check in the one caller whether we've exceeded the limit. - Change the name of radix_tree_iter_save() back to radix_tree_iter_next(). I went back and forth on this one, and could easily be convinced to rename it as I think radix_tree_iter_save() makes more sense to the callers. - Add radix_tree_iter_delete() instead of poking around the internals of the radix tree in ida_destroy() - Add accessors for the idr cyclic allocation cursor Patches 1-9: Test suite improvements, including Konstantin's benchmark Patches 10-12: join/split (Kirill wants these for huge page cache) Patches 13-17: General improvements to the radix tree Patches 18-22: Radix tree iterator improvements Patches 23-29: Replace the IDR with the radix tree Konstantin Khlebnikov (1): radix tree test suite: benchmark for iterator Matthew Wilcox (28): tools: Add WARN_ON_ONCE radix tree test suite: Allow GFP_ATOMIC allocations to fail radix tree test suite: Track preempt_count radix tree test suite: Free preallocated nodes radix tree test suite: Make runs more reproducible radix tree test suite: Use rcu_barrier tools: Add more bitmap functions radix tree test suite: Use common find-bit code radix-tree: Add radix_tree_join radix-tree: Add radix_tree_split radix-tree: Add radix_tree_split_preload() radix-tree: Fix typo radix-tree: Move rcu_head into a union with private_list radix-tree: Create node_tag_set() radix-tree: Make radix_tree_find_next_bit more useful radix-tree: Improve dump output btrfs: Fix race in btrfs_free_dummy_fs_info() radix tree test suite: iteration test misuses RCU radix tree: Improve multiorder iterators radix-tree: Delete radix_tree_locate_item() radix-tree: Delete radix_tree_range_tag_if_tagged() idr: Add ida_is_empty tpm: Use idr_find(), not idr_find_slowpath() rxrpc: Abstract away knowledge of IDR internals idr: Reduce the number of bits per level from 8 to 6 radix tree test suite: Add some more functionality radix-tree: Create all_tag_set Reimplement IDR and IDA using the radix tree drivers/char/tpm/tpm-chip.c | 4 +- drivers/usb/gadget/function/f_hid.c | 6 +- drivers/usb/gadget/function/f_printer.c | 6 +- fs/btrfs/tests/btrfs-tests.c | 1 + include/linux/idr.h | 156 +-- include/linux/radix-tree.h | 161 ++- init/main.c | 3 +- lib/idr.c | 1075 ---------------- lib/radix-tree.c | 1328 +++++++++++++++----- mm/khugepaged.c | 2 +- mm/page-writeback.c | 28 +- mm/shmem.c | 32 +- net/rxrpc/af_rxrpc.c | 11 +- net/rxrpc/conn_client.c | 4 +- tools/include/asm/bug.h | 11 + tools/include/linux/bitmap.h | 26 + tools/lib/find_bit.c | 8 + tools/testing/radix-tree/Makefile | 18 +- tools/testing/radix-tree/benchmark.c | 98 ++ tools/testing/radix-tree/find_next_bit.c | 57 - tools/testing/radix-tree/idr.c | 148 +++ tools/testing/radix-tree/iteration_check.c | 39 +- tools/testing/radix-tree/linux.c | 23 +- tools/testing/radix-tree/linux/bitops.h | 40 +- tools/testing/radix-tree/linux/bitops/non-atomic.h | 13 +- tools/testing/radix-tree/linux/bug.h | 2 +- tools/testing/radix-tree/linux/gfp.h | 22 +- tools/testing/radix-tree/linux/idr.h | 1 + tools/testing/radix-tree/linux/kernel.h | 20 + tools/testing/radix-tree/linux/preempt.h | 6 +- tools/testing/radix-tree/linux/slab.h | 6 +- tools/testing/radix-tree/linux/types.h | 2 - tools/testing/radix-tree/main.c | 80 +- tools/testing/radix-tree/multiorder.c | 111 +- tools/testing/radix-tree/regression2.c | 3 +- tools/testing/radix-tree/regression3.c | 6 +- tools/testing/radix-tree/tag_check.c | 9 +- tools/testing/radix-tree/test.c | 47 + tools/testing/radix-tree/test.h | 18 + 39 files changed, 1884 insertions(+), 1747 deletions(-) create mode 100644 tools/testing/radix-tree/benchmark.c delete mode 100644 tools/testing/radix-tree/find_next_bit.c create mode 100644 tools/testing/radix-tree/idr.c create mode 100644 tools/testing/radix-tree/linux/idr.h -- 2.10.2
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| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 06/29] radix tree test suite: benchmark for iterator |
| Message-ID | <sEgSm-rg-7@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Konstantin Khlebnikov <koct9i@gmail.com>
This adds simple benchmark for iterator similar to one I've used for
commit 78c1d78 ("radix-tree: introduce bit-optimized iterator")
Building with make BENCHMARK=1 set radix tree order to 6, this allows
to get performance comparable to in kernel performance.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
tools/testing/radix-tree/Makefile | 6 +-
tools/testing/radix-tree/benchmark.c | 98 +++++++++++++++++++++++++++++++++
tools/testing/radix-tree/linux/kernel.h | 4 ++
tools/testing/radix-tree/main.c | 2 +
tools/testing/radix-tree/test.h | 1 +
5 files changed, 110 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/radix-tree/benchmark.c
diff --git a/tools/testing/radix-tree/Makefile b/tools/testing/radix-tree/Makefile
index 3c338dc..08283a8 100644
--- a/tools/testing/radix-tree/Makefile
+++ b/tools/testing/radix-tree/Makefile
@@ -4,7 +4,11 @@ LDFLAGS += -lpthread -lurcu
TARGETS = main
OFILES = main.o radix-tree.o linux.o test.o tag_check.o find_next_bit.o \
regression1.o regression2.o regression3.o multiorder.o \
- iteration_check.o
+ iteration_check.o benchmark.o
+
+ifdef BENCHMARK
+ CFLAGS += -DBENCHMARK=1
+endif
targets: $(TARGETS)
diff --git a/tools/testing/radix-tree/benchmark.c b/tools/testing/radix-tree/benchmark.c
new file mode 100644
index 0000000..215ca86
--- /dev/null
+++ b/tools/testing/radix-tree/benchmark.c
@@ -0,0 +1,98 @@
+/*
+ * benchmark.c:
+ * Author: Konstantin Khlebnikov <koct9i@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+#include <linux/radix-tree.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <time.h>
+#include "test.h"
+
+#define NSEC_PER_SEC 1000000000L
+
+static long long benchmark_iter(struct radix_tree_root *root, bool tagged)
+{
+ volatile unsigned long sink = 0;
+ struct radix_tree_iter iter;
+ struct timespec start, finish;
+ long long nsec;
+ int l, loops = 1;
+ void **slot;
+
+#ifdef BENCHMARK
+again:
+#endif
+ clock_gettime(CLOCK_MONOTONIC, &start);
+ for (l = 0; l < loops; l++) {
+ if (tagged) {
+ radix_tree_for_each_tagged(slot, root, &iter, 0, 0)
+ sink ^= (unsigned long)slot;
+ } else {
+ radix_tree_for_each_slot(slot, root, &iter, 0)
+ sink ^= (unsigned long)slot;
+ }
+ }
+ clock_gettime(CLOCK_MONOTONIC, &finish);
+
+ nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC +
+ (finish.tv_nsec - start.tv_nsec);
+
+#ifdef BENCHMARK
+ if (loops == 1 && nsec * 5 < NSEC_PER_SEC) {
+ loops = NSEC_PER_SEC / nsec / 4 + 1;
+ goto again;
+ }
+#endif
+
+ nsec /= loops;
+ return nsec;
+}
+
+static void benchmark_size(unsigned long size, unsigned long step, int order)
+{
+ RADIX_TREE(tree, GFP_KERNEL);
+ long long normal, tagged;
+ unsigned long index;
+
+ for (index = 0 ; index < size ; index += step) {
+ item_insert_order(&tree, index, order);
+ radix_tree_tag_set(&tree, index, 0);
+ }
+
+ tagged = benchmark_iter(&tree, true);
+ normal = benchmark_iter(&tree, false);
+
+ printf("Size %ld, step %6ld, order %d tagged %10lld ns, normal %10lld ns\n",
+ size, step, order, tagged, normal);
+
+ item_kill_tree(&tree);
+ rcu_barrier();
+}
+
+void benchmark(void)
+{
+ unsigned long size[] = {1 << 10, 1 << 20, 0};
+ unsigned long step[] = {1, 2, 7, 15, 63, 64, 65,
+ 128, 256, 512, 12345, 0};
+ int c, s;
+
+ printf("starting benchmarks\n");
+ printf("RADIX_TREE_MAP_SHIFT = %d\n", RADIX_TREE_MAP_SHIFT);
+
+ for (c = 0; size[c]; c++)
+ for (s = 0; step[s]; s++)
+ benchmark_size(size[c], step[s], 0);
+
+ for (c = 0; size[c]; c++)
+ for (s = 0; step[s]; s++)
+ benchmark_size(size[c], step[s] << 9, 9);
+}
diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h
index be98a47..dbe4b92 100644
--- a/tools/testing/radix-tree/linux/kernel.h
+++ b/tools/testing/radix-tree/linux/kernel.h
@@ -10,7 +10,11 @@
#include "../../include/linux/compiler.h"
#include "../../../include/linux/kconfig.h"
+#ifdef BENCHMARK
+#define RADIX_TREE_MAP_SHIFT 6
+#else
#define RADIX_TREE_MAP_SHIFT 3
+#endif
#ifndef NULL
#define NULL 0
diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c
index 5ddec8e..f43706c 100644
--- a/tools/testing/radix-tree/main.c
+++ b/tools/testing/radix-tree/main.c
@@ -352,6 +352,8 @@ int main(int argc, char **argv)
/* Free any remaining preallocated nodes */
radix_tree_callback(NULL, CPU_DEAD, NULL);
+ benchmark();
+
sleep(1);
printf("after sleep(1): %d allocated, preempt %d\n",
nr_allocated, preempt_count);
diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h
index 8cd666a..f2dc35f 100644
--- a/tools/testing/radix-tree/test.h
+++ b/tools/testing/radix-tree/test.h
@@ -30,6 +30,7 @@ void item_kill_tree(struct radix_tree_root *root);
void tag_check(void);
void multiorder_checks(void);
void iteration_test(void);
+void benchmark(void);
struct item *
item_tag_set(struct radix_tree_root *root, unsigned long index, int tag);
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 07/29] radix tree test suite: Use rcu_barrier |
| Message-ID | <sEgSm-rg-31@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <mawilcox@microsoft.com>
Calling rcu_barrier() allows all of the rcu-freed memory to be actually
returned to the pool, and allows nr_allocated to return to 0. As well
as allowing diffs between runs to be more useful, it also lets us
pinpoint leaks more effectively.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
tools/testing/radix-tree/main.c | 12 ++++++++++--
tools/testing/radix-tree/tag_check.c | 5 +++++
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c
index f43706c..8621542 100644
--- a/tools/testing/radix-tree/main.c
+++ b/tools/testing/radix-tree/main.c
@@ -295,24 +295,31 @@ static void single_thread_tests(bool long_run)
printf("starting single_thread_tests: %d allocated, preempt %d\n",
nr_allocated, preempt_count);
multiorder_checks();
+ rcu_barrier();
printf("after multiorder_check: %d allocated, preempt %d\n",
nr_allocated, preempt_count);
locate_check();
+ rcu_barrier();
printf("after locate_check: %d allocated, preempt %d\n",
nr_allocated, preempt_count);
tag_check();
+ rcu_barrier();
printf("after tag_check: %d allocated, preempt %d\n",
nr_allocated, preempt_count);
gang_check();
+ rcu_barrier();
printf("after gang_check: %d allocated, preempt %d\n",
nr_allocated, preempt_count);
add_and_check();
+ rcu_barrier();
printf("after add_and_check: %d allocated, preempt %d\n",
nr_allocated, preempt_count);
dynamic_height_check();
+ rcu_barrier();
printf("after dynamic_height_check: %d allocated, preempt %d\n",
nr_allocated, preempt_count);
big_gang_check(long_run);
+ rcu_barrier();
printf("after big_gang_check: %d allocated, preempt %d\n",
nr_allocated, preempt_count);
for (i = 0; i < (long_run ? 2000 : 3); i++) {
@@ -320,6 +327,7 @@ static void single_thread_tests(bool long_run)
printf("%d ", i);
fflush(stdout);
}
+ rcu_barrier();
printf("after copy_tag_check: %d allocated, preempt %d\n",
nr_allocated, preempt_count);
}
@@ -354,8 +362,8 @@ int main(int argc, char **argv)
benchmark();
- sleep(1);
- printf("after sleep(1): %d allocated, preempt %d\n",
+ rcu_barrier();
+ printf("after rcu_barrier: %d allocated, preempt %d\n",
nr_allocated, preempt_count);
rcu_unregister_thread();
diff --git a/tools/testing/radix-tree/tag_check.c b/tools/testing/radix-tree/tag_check.c
index b0ac057..186f6e4 100644
--- a/tools/testing/radix-tree/tag_check.c
+++ b/tools/testing/radix-tree/tag_check.c
@@ -51,6 +51,7 @@ void simple_checks(void)
verify_tag_consistency(&tree, 1);
printf("before item_kill_tree: %d allocated\n", nr_allocated);
item_kill_tree(&tree);
+ rcu_barrier();
printf("after item_kill_tree: %d allocated\n", nr_allocated);
}
@@ -331,12 +332,16 @@ void tag_check(void)
single_check();
extend_checks();
contract_checks();
+ rcu_barrier();
printf("after extend_checks: %d allocated\n", nr_allocated);
__leak_check();
leak_check();
+ rcu_barrier();
printf("after leak_check: %d allocated\n", nr_allocated);
simple_checks();
+ rcu_barrier();
printf("after simple_checks: %d allocated\n", nr_allocated);
thrash_tags();
+ rcu_barrier();
printf("after thrash_tags: %d allocated\n", nr_allocated);
}
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 24/29] tpm: Use idr_find(), not idr_find_slowpath() |
| Message-ID | <sEgSm-rg-35@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <mawilcox@microsoft.com>
idr_find_slowpath() is not intended to be part of the public API, it's
an implementation detail. There's no reason to skip straight to the
slowpath here.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
drivers/char/tpm/tpm-chip.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index e595013..447b6ca 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -84,7 +84,7 @@ EXPORT_SYMBOL_GPL(tpm_put_ops);
*
* The return'd chip has been tpm_try_get_ops'd and must be released via
* tpm_put_ops
- */
+ */
struct tpm_chip *tpm_chip_find_get(int chip_num)
{
struct tpm_chip *chip, *res = NULL;
@@ -103,7 +103,7 @@ struct tpm_chip *tpm_chip_find_get(int chip_num)
}
} while (chip_prev != chip_num);
} else {
- chip = idr_find_slowpath(&dev_nums_idr, chip_num);
+ chip = idr_find(&dev_nums_idr, chip_num);
if (chip && !tpm_try_get_ops(chip))
res = chip;
}
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 01/29] tools: Add WARN_ON_ONCE |
| Message-ID | <sEgSm-rg-15@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <willy@linux.intel.com>
The radix tree uses its own buggy WARN_ON_ONCE. Replace it with the
definition from asm-generic/bug.h
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
tools/include/asm/bug.h | 11 +++++++++++
tools/testing/radix-tree/Makefile | 2 +-
tools/testing/radix-tree/linux/bug.h | 2 +-
tools/testing/radix-tree/linux/types.h | 2 --
4 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/tools/include/asm/bug.h b/tools/include/asm/bug.h
index 9e5f484..beda1a8 100644
--- a/tools/include/asm/bug.h
+++ b/tools/include/asm/bug.h
@@ -12,6 +12,17 @@
unlikely(__ret_warn_on); \
})
+#define WARN_ON_ONCE(condition) ({ \
+ static int __warned; \
+ int __ret_warn_once = !!(condition); \
+ \
+ if (unlikely(__ret_warn_once && !__warned)) { \
+ __warned = true; \
+ WARN_ON(1); \
+ } \
+ unlikely(__ret_warn_once); \
+})
+
#define WARN_ONCE(condition, format...) ({ \
static int __warned; \
int __ret_warn_once = !!(condition); \
diff --git a/tools/testing/radix-tree/Makefile b/tools/testing/radix-tree/Makefile
index f2e07f2..3c338dc 100644
--- a/tools/testing/radix-tree/Makefile
+++ b/tools/testing/radix-tree/Makefile
@@ -1,5 +1,5 @@
-CFLAGS += -I. -g -O2 -Wall -D_LGPL_SOURCE
+CFLAGS += -I. -I../../include -g -O2 -Wall -D_LGPL_SOURCE
LDFLAGS += -lpthread -lurcu
TARGETS = main
OFILES = main.o radix-tree.o linux.o test.o tag_check.o find_next_bit.o \
diff --git a/tools/testing/radix-tree/linux/bug.h b/tools/testing/radix-tree/linux/bug.h
index ccbe444..23b8ed5 100644
--- a/tools/testing/radix-tree/linux/bug.h
+++ b/tools/testing/radix-tree/linux/bug.h
@@ -1 +1 @@
-#define WARN_ON_ONCE(x) assert(x)
+#include "asm/bug.h"
diff --git a/tools/testing/radix-tree/linux/types.h b/tools/testing/radix-tree/linux/types.h
index faa0b6f..8491d89 100644
--- a/tools/testing/radix-tree/linux/types.h
+++ b/tools/testing/radix-tree/linux/types.h
@@ -6,8 +6,6 @@
#define __rcu
#define __read_mostly
-#define BITS_PER_LONG (sizeof(long) * 8)
-
static inline void INIT_LIST_HEAD(struct list_head *list)
{
list->next = list;
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 06/29] radix tree test suite: benchmark for iterator |
| Message-ID | <sEgSm-rg-17@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Konstantin Khlebnikov <koct9i@gmail.com>
This adds simple benchmark for iterator similar to one I've used for
commit 78c1d78 ("radix-tree: introduce bit-optimized iterator")
Building with make BENCHMARK=1 set radix tree order to 6, this allows
to get performance comparable to in kernel performance.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
tools/testing/radix-tree/Makefile | 6 +-
tools/testing/radix-tree/benchmark.c | 98 +++++++++++++++++++++++++++++++++
tools/testing/radix-tree/linux/kernel.h | 4 ++
tools/testing/radix-tree/main.c | 2 +
tools/testing/radix-tree/test.h | 1 +
5 files changed, 110 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/radix-tree/benchmark.c
diff --git a/tools/testing/radix-tree/Makefile b/tools/testing/radix-tree/Makefile
index 3c338dc..08283a8 100644
--- a/tools/testing/radix-tree/Makefile
+++ b/tools/testing/radix-tree/Makefile
@@ -4,7 +4,11 @@ LDFLAGS += -lpthread -lurcu
TARGETS = main
OFILES = main.o radix-tree.o linux.o test.o tag_check.o find_next_bit.o \
regression1.o regression2.o regression3.o multiorder.o \
- iteration_check.o
+ iteration_check.o benchmark.o
+
+ifdef BENCHMARK
+ CFLAGS += -DBENCHMARK=1
+endif
targets: $(TARGETS)
diff --git a/tools/testing/radix-tree/benchmark.c b/tools/testing/radix-tree/benchmark.c
new file mode 100644
index 0000000..215ca86
--- /dev/null
+++ b/tools/testing/radix-tree/benchmark.c
@@ -0,0 +1,98 @@
+/*
+ * benchmark.c:
+ * Author: Konstantin Khlebnikov <koct9i@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+#include <linux/radix-tree.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <time.h>
+#include "test.h"
+
+#define NSEC_PER_SEC 1000000000L
+
+static long long benchmark_iter(struct radix_tree_root *root, bool tagged)
+{
+ volatile unsigned long sink = 0;
+ struct radix_tree_iter iter;
+ struct timespec start, finish;
+ long long nsec;
+ int l, loops = 1;
+ void **slot;
+
+#ifdef BENCHMARK
+again:
+#endif
+ clock_gettime(CLOCK_MONOTONIC, &start);
+ for (l = 0; l < loops; l++) {
+ if (tagged) {
+ radix_tree_for_each_tagged(slot, root, &iter, 0, 0)
+ sink ^= (unsigned long)slot;
+ } else {
+ radix_tree_for_each_slot(slot, root, &iter, 0)
+ sink ^= (unsigned long)slot;
+ }
+ }
+ clock_gettime(CLOCK_MONOTONIC, &finish);
+
+ nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC +
+ (finish.tv_nsec - start.tv_nsec);
+
+#ifdef BENCHMARK
+ if (loops == 1 && nsec * 5 < NSEC_PER_SEC) {
+ loops = NSEC_PER_SEC / nsec / 4 + 1;
+ goto again;
+ }
+#endif
+
+ nsec /= loops;
+ return nsec;
+}
+
+static void benchmark_size(unsigned long size, unsigned long step, int order)
+{
+ RADIX_TREE(tree, GFP_KERNEL);
+ long long normal, tagged;
+ unsigned long index;
+
+ for (index = 0 ; index < size ; index += step) {
+ item_insert_order(&tree, index, order);
+ radix_tree_tag_set(&tree, index, 0);
+ }
+
+ tagged = benchmark_iter(&tree, true);
+ normal = benchmark_iter(&tree, false);
+
+ printf("Size %ld, step %6ld, order %d tagged %10lld ns, normal %10lld ns\n",
+ size, step, order, tagged, normal);
+
+ item_kill_tree(&tree);
+ rcu_barrier();
+}
+
+void benchmark(void)
+{
+ unsigned long size[] = {1 << 10, 1 << 20, 0};
+ unsigned long step[] = {1, 2, 7, 15, 63, 64, 65,
+ 128, 256, 512, 12345, 0};
+ int c, s;
+
+ printf("starting benchmarks\n");
+ printf("RADIX_TREE_MAP_SHIFT = %d\n", RADIX_TREE_MAP_SHIFT);
+
+ for (c = 0; size[c]; c++)
+ for (s = 0; step[s]; s++)
+ benchmark_size(size[c], step[s], 0);
+
+ for (c = 0; size[c]; c++)
+ for (s = 0; step[s]; s++)
+ benchmark_size(size[c], step[s] << 9, 9);
+}
diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h
index be98a47..dbe4b92 100644
--- a/tools/testing/radix-tree/linux/kernel.h
+++ b/tools/testing/radix-tree/linux/kernel.h
@@ -10,7 +10,11 @@
#include "../../include/linux/compiler.h"
#include "../../../include/linux/kconfig.h"
+#ifdef BENCHMARK
+#define RADIX_TREE_MAP_SHIFT 6
+#else
#define RADIX_TREE_MAP_SHIFT 3
+#endif
#ifndef NULL
#define NULL 0
diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c
index 5ddec8e..f43706c 100644
--- a/tools/testing/radix-tree/main.c
+++ b/tools/testing/radix-tree/main.c
@@ -352,6 +352,8 @@ int main(int argc, char **argv)
/* Free any remaining preallocated nodes */
radix_tree_callback(NULL, CPU_DEAD, NULL);
+ benchmark();
+
sleep(1);
printf("after sleep(1): %d allocated, preempt %d\n",
nr_allocated, preempt_count);
diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h
index 8cd666a..f2dc35f 100644
--- a/tools/testing/radix-tree/test.h
+++ b/tools/testing/radix-tree/test.h
@@ -30,6 +30,7 @@ void item_kill_tree(struct radix_tree_root *root);
void tag_check(void);
void multiorder_checks(void);
void iteration_test(void);
+void benchmark(void);
struct item *
item_tag_set(struct radix_tree_root *root, unsigned long index, int tag);
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 20/29] radix tree: Improve multiorder iterators |
| Message-ID | <sEgSm-rg-37@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <mawilcox@microsoft.com>
This fixes several interlinked problems with the iterators in the
presence of multiorder entries.
1. radix_tree_iter_next() would only advance by one slot, which would
result in the iterators returning the same entry more than once if there
were sibling entries.
2. radix_tree_next_slot() could return an internal pointer instead of
a user pointer if a tagged multiorder entry was immediately followed by
an entry of lower order.
3. radix_tree_next_slot() expanded to a lot more code than it used to
when multiorder support was compiled in. And I wasn't comfortable with
entry_to_node() being in a header file.
Fixing radix_tree_iter_next() for the presence of sibling entries
necessarily involves examining the contents of the radix tree, so we now
need to pass 'slot' to radix_tree_iter_next(), and we need to change the
calling convention so it is called *before* dropping the lock which
protects the tree. Fortunately, unconverted code won't compile.
radix_tree_next_slot() becomes closer to how it looked before multiorder
support was introduced. It only checks to see if the next entry in the
chunk is a sibling entry or a pointer to a node; this should be rare
enough that handling this case out of line is not a performance impact
(and such impact is amortised by the fact that the entry we just
processed was a multiorder entry). Also, radix_tree_next_slot() used
to force a new chunk lookup for untagged entries, which is more
expensive than the out of line sibling entry skipping.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
fs/btrfs/tests/btrfs-tests.c | 2 +-
include/linux/radix-tree.h | 63 ++++++++------------
lib/radix-tree.c | 94 ++++++++++++++++++++++++++++++
mm/khugepaged.c | 2 +-
mm/shmem.c | 6 +-
tools/testing/radix-tree/iteration_check.c | 4 +-
tools/testing/radix-tree/multiorder.c | 12 ++++
tools/testing/radix-tree/regression3.c | 6 +-
tools/testing/radix-tree/test.h | 1 +
9 files changed, 142 insertions(+), 48 deletions(-)
diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c
index 73076a0..6d3457a 100644
--- a/fs/btrfs/tests/btrfs-tests.c
+++ b/fs/btrfs/tests/btrfs-tests.c
@@ -162,7 +162,7 @@ void btrfs_free_dummy_fs_info(struct btrfs_fs_info *fs_info)
slot = radix_tree_iter_retry(&iter);
continue;
}
- slot = radix_tree_iter_next(&iter);
+ slot = radix_tree_iter_next(slot, &iter);
spin_unlock(&fs_info->buffer_lock);
free_extent_buffer_stale(eb);
spin_lock(&fs_info->buffer_lock);
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index 66fb8c0..36c6175 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -424,15 +424,10 @@ __radix_tree_iter_add(struct radix_tree_iter *iter, unsigned long slots)
*
* If the iterator needs to release then reacquire a lock, the chunk may
* have been invalidated by an insertion or deletion. Call this function
- * to continue the iteration from the next index.
+ * before releasing the lock to continue the iteration from the next index.
*/
-static inline __must_check
-void **radix_tree_iter_next(struct radix_tree_iter *iter)
-{
- iter->next_index = __radix_tree_iter_add(iter, 1);
- iter->tags = 0;
- return NULL;
-}
+void **__must_check radix_tree_iter_next(void **slot,
+ struct radix_tree_iter *iter);
/**
* radix_tree_chunk_size - get current chunk size
@@ -446,10 +441,17 @@ radix_tree_chunk_size(struct radix_tree_iter *iter)
return (iter->next_index - iter->index) >> iter_shift(iter);
}
-static inline struct radix_tree_node *entry_to_node(void *ptr)
+#ifdef CONFIG_RADIX_TREE_MULTIORDER
+void ** __radix_tree_next_slot(void **slot, struct radix_tree_iter *iter,
+ unsigned flags);
+#else
+/* Can't happen without sibling entries, but the compiler can't tell that */
+static inline void ** __radix_tree_next_slot(void **slot,
+ struct radix_tree_iter *iter, unsigned flags)
{
- return (void *)((unsigned long)ptr & ~RADIX_TREE_INTERNAL_NODE);
+ return slot;
}
+#endif
/**
* radix_tree_next_slot - find next slot in chunk
@@ -474,51 +476,31 @@ static __always_inline void **
radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
{
if (flags & RADIX_TREE_ITER_TAGGED) {
- void *canon = slot;
-
iter->tags >>= 1;
if (unlikely(!iter->tags))
return NULL;
- while (IS_ENABLED(CONFIG_RADIX_TREE_MULTIORDER) &&
- radix_tree_is_internal_node(slot[1])) {
- if (entry_to_node(slot[1]) == canon) {
- iter->tags >>= 1;
- iter->index = __radix_tree_iter_add(iter, 1);
- slot++;
- continue;
- }
- iter->next_index = __radix_tree_iter_add(iter, 1);
- return NULL;
- }
if (likely(iter->tags & 1ul)) {
iter->index = __radix_tree_iter_add(iter, 1);
- return slot + 1;
+ slot++;
+ goto found;
}
if (!(flags & RADIX_TREE_ITER_CONTIG)) {
unsigned offset = __ffs(iter->tags);
- iter->tags >>= offset;
- iter->index = __radix_tree_iter_add(iter, offset + 1);
- return slot + offset + 1;
+ iter->tags >>= offset++;
+ iter->index = __radix_tree_iter_add(iter, offset);
+ slot += offset;
+ goto found;
}
} else {
long count = radix_tree_chunk_size(iter);
- void *canon = slot;
while (--count > 0) {
slot++;
iter->index = __radix_tree_iter_add(iter, 1);
- if (IS_ENABLED(CONFIG_RADIX_TREE_MULTIORDER) &&
- radix_tree_is_internal_node(*slot)) {
- if (entry_to_node(*slot) == canon)
- continue;
- iter->next_index = iter->index;
- break;
- }
-
if (likely(*slot))
- return slot;
+ goto found;
if (flags & RADIX_TREE_ITER_CONTIG) {
/* forbid switching to the next chunk */
iter->next_index = 0;
@@ -527,6 +509,11 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
}
}
return NULL;
+
+ found:
+ if (unlikely(radix_tree_is_internal_node(*slot)))
+ return __radix_tree_next_slot(slot, iter, flags);
+ return slot;
}
/**
@@ -577,6 +564,6 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
slot || (slot = radix_tree_next_chunk(root, iter, \
RADIX_TREE_ITER_TAGGED | tag)) ; \
slot = radix_tree_next_slot(slot, iter, \
- RADIX_TREE_ITER_TAGGED))
+ RADIX_TREE_ITER_TAGGED | tag))
#endif /* _LINUX_RADIX_TREE_H */
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 09c5f1d..27b53ef 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -69,6 +69,11 @@ struct radix_tree_preload {
};
static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, };
+static inline struct radix_tree_node *entry_to_node(void *ptr)
+{
+ return (void *)((unsigned long)ptr & ~RADIX_TREE_INTERNAL_NODE);
+}
+
static inline void *node_to_entry(void *ptr)
{
return (void *)((unsigned long)ptr | RADIX_TREE_INTERNAL_NODE);
@@ -1138,6 +1143,95 @@ static inline void __set_iter_shift(struct radix_tree_iter *iter,
#endif
}
+static void ** __radix_tree_iter_next(struct radix_tree_node **nodep,
+ void **slot, struct radix_tree_iter *iter)
+{
+ void *sib = node_to_entry(slot - 1);
+
+ while (iter->index < iter->next_index) {
+ *nodep = rcu_dereference_raw(*slot);
+ if (*nodep && *nodep != sib)
+ return slot;
+ slot++;
+ iter->index = __radix_tree_iter_add(iter, 1);
+ iter->tags >>= 1;
+ }
+
+ *nodep = NULL;
+ return NULL;
+}
+
+#ifdef CONFIG_RADIX_TREE_MULTIORDER
+void ** __radix_tree_next_slot(void **slot, struct radix_tree_iter *iter,
+ unsigned flags)
+{
+ unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK;
+ struct radix_tree_node *node = rcu_dereference_raw(*slot);
+
+ slot = __radix_tree_iter_next(&node, slot, iter);
+
+ while (radix_tree_is_internal_node(node)) {
+ unsigned offset;
+
+ if (node == RADIX_TREE_RETRY)
+ return slot;
+ node = entry_to_node(node);
+
+ if (flags & RADIX_TREE_ITER_TAGGED) {
+ unsigned tag_long, tag_bit;
+ offset = radix_tree_find_next_bit(node, tag, 0);
+ if (offset == RADIX_TREE_MAP_SIZE)
+ return NULL;
+ slot = &node->slots[offset];
+
+ tag_long = offset / BITS_PER_LONG;
+ tag_bit = offset % BITS_PER_LONG;
+ iter->tags = node->tags[tag][tag_long] >> tag_bit;
+ BUG_ON(iter->tags >= (RADIX_TREE_MAP_SIZE * 2));
+ node = rcu_dereference_raw(*slot);
+ } else {
+ offset = 0;
+ slot = &node->slots[0];
+ for (;;) {
+ node = rcu_dereference_raw(*slot);
+ if (node)
+ break;
+ slot++;
+ offset++;
+ if (offset == RADIX_TREE_MAP_SIZE)
+ return NULL;
+ }
+ }
+ if ((flags & RADIX_TREE_ITER_CONTIG) && (offset > 0))
+ goto none;
+ iter->shift -= RADIX_TREE_MAP_SHIFT;
+ iter->index = __radix_tree_iter_add(iter, offset);
+ iter->next_index = (iter->index | shift_maxindex(iter->shift)) +
+ 1;
+ }
+
+ return slot;
+ none:
+ iter->next_index = 0;
+ return NULL;
+}
+EXPORT_SYMBOL(__radix_tree_next_slot);
+#endif
+
+void **radix_tree_iter_next(void **slot, struct radix_tree_iter *iter)
+{
+ struct radix_tree_node *node;
+
+ slot++;
+ iter->index = __radix_tree_iter_add(iter, 1);
+ node = rcu_dereference_raw(*slot);
+ __radix_tree_iter_next(&node, slot, iter);
+ iter->next_index = iter->index;
+ iter->tags = 0;
+ return NULL;
+}
+EXPORT_SYMBOL(radix_tree_iter_next);
+
/**
* radix_tree_next_chunk - find next chunk of slots for iteration
*
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 728d779..46155d1 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1614,8 +1614,8 @@ static void khugepaged_scan_shmem(struct mm_struct *mm,
present++;
if (need_resched()) {
+ slot = radix_tree_iter_next(slot, &iter);
cond_resched_rcu();
- slot = radix_tree_iter_next(&iter);
}
}
rcu_read_unlock();
diff --git a/mm/shmem.c b/mm/shmem.c
index 166ebf5..0b3fe33 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -658,8 +658,8 @@ unsigned long shmem_partial_swap_usage(struct address_space *mapping,
swapped++;
if (need_resched()) {
+ slot = radix_tree_iter_next(slot, &iter);
cond_resched_rcu();
- slot = radix_tree_iter_next(&iter);
}
}
@@ -2434,8 +2434,8 @@ static void shmem_tag_pins(struct address_space *mapping)
}
if (need_resched()) {
+ slot = radix_tree_iter_next(slot, &iter);
cond_resched_rcu();
- slot = radix_tree_iter_next(&iter);
}
}
rcu_read_unlock();
@@ -2504,8 +2504,8 @@ static int shmem_wait_for_pins(struct address_space *mapping)
spin_unlock_irq(&mapping->tree_lock);
continue_resched:
if (need_resched()) {
+ slot = radix_tree_iter_next(slot, &iter);
cond_resched_rcu();
- slot = radix_tree_iter_next(&iter);
}
}
rcu_read_unlock();
diff --git a/tools/testing/radix-tree/iteration_check.c b/tools/testing/radix-tree/iteration_check.c
index df71cb8..6eca4c2 100644
--- a/tools/testing/radix-tree/iteration_check.c
+++ b/tools/testing/radix-tree/iteration_check.c
@@ -79,7 +79,7 @@ static void *tagged_iteration_fn(void *arg)
}
if (rand_r(&seeds[0]) % 50 == 0) {
- slot = radix_tree_iter_next(&iter);
+ slot = radix_tree_iter_next(slot, &iter);
rcu_read_unlock();
rcu_barrier();
rcu_read_lock();
@@ -127,7 +127,7 @@ static void *untagged_iteration_fn(void *arg)
}
if (rand_r(&seeds[1]) % 50 == 0) {
- slot = radix_tree_iter_next(&iter);
+ slot = radix_tree_iter_next(slot, &iter);
rcu_read_unlock();
rcu_barrier();
rcu_read_lock();
diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index 25e0463..588209a 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -232,10 +232,14 @@ void multiorder_iteration(void)
int height = order[i] / RADIX_TREE_MAP_SHIFT;
int shift = height * RADIX_TREE_MAP_SHIFT;
int mask = (1 << order[i]) - 1;
+ struct item *item = *slot;
assert(iter.index >= (index[i] &~ mask));
assert(iter.index <= (index[i] | mask));
assert(iter.shift == shift);
+ assert(!radix_tree_is_internal_node(item));
+ assert(item->index >= (index[i] &~ mask));
+ assert(item->index <= (index[i] | mask));
i++;
}
}
@@ -279,12 +283,16 @@ void multiorder_tagged_iteration(void)
}
radix_tree_for_each_tagged(slot, &tree, &iter, j, 1) {
+ struct item *item = *slot;
for (k = i; index[k] < tag_index[i]; k++)
;
mask = (1 << order[k]) - 1;
assert(iter.index >= (tag_index[i] &~ mask));
assert(iter.index <= (tag_index[i] | mask));
+ assert(!radix_tree_is_internal_node(item));
+ assert(item->index >= (tag_index[i] &~ mask));
+ assert(item->index <= (tag_index[i] | mask));
i++;
}
}
@@ -303,12 +311,16 @@ void multiorder_tagged_iteration(void)
}
radix_tree_for_each_tagged(slot, &tree, &iter, j, 2) {
+ struct item *item = *slot;
for (k = i; index[k] < tag_index[i]; k++)
;
mask = (1 << order[k]) - 1;
assert(iter.index >= (tag_index[i] &~ mask));
assert(iter.index <= (tag_index[i] | mask));
+ assert(!radix_tree_is_internal_node(item));
+ assert(item->index >= (tag_index[i] &~ mask));
+ assert(item->index <= (tag_index[i] | mask));
i++;
}
}
diff --git a/tools/testing/radix-tree/regression3.c b/tools/testing/radix-tree/regression3.c
index 1f06ed7..4d28eeb 100644
--- a/tools/testing/radix-tree/regression3.c
+++ b/tools/testing/radix-tree/regression3.c
@@ -88,7 +88,7 @@ void regression3_test(void)
printf("slot %ld %p\n", iter.index, *slot);
if (!iter.index) {
printf("next at %ld\n", iter.index);
- slot = radix_tree_iter_next(&iter);
+ slot = radix_tree_iter_next(slot, &iter);
}
}
@@ -96,7 +96,7 @@ void regression3_test(void)
printf("contig %ld %p\n", iter.index, *slot);
if (!iter.index) {
printf("next at %ld\n", iter.index);
- slot = radix_tree_iter_next(&iter);
+ slot = radix_tree_iter_next(slot, &iter);
}
}
@@ -106,7 +106,7 @@ void regression3_test(void)
printf("tagged %ld %p\n", iter.index, *slot);
if (!iter.index) {
printf("next at %ld\n", iter.index);
- slot = radix_tree_iter_next(&iter);
+ slot = radix_tree_iter_next(slot, &iter);
}
}
diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h
index 33d2b6b..b678f13 100644
--- a/tools/testing/radix-tree/test.h
+++ b/tools/testing/radix-tree/test.h
@@ -43,6 +43,7 @@ void verify_tag_consistency(struct radix_tree_root *root, unsigned int tag);
extern int nr_allocated;
/* Normally private parts of lib/radix-tree.c */
+struct radix_tree_node *entry_to_node(void *ptr);
void radix_tree_dump(struct radix_tree_root *root);
int root_tag_get(struct radix_tree_root *root, unsigned int tag);
unsigned long node_maxindex(struct radix_tree_node *);
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 12/29] radix-tree: Add radix_tree_split_preload() |
| Message-ID | <sEgSm-rg-41@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <willy@linux.intel.com>
Calculate how many nodes we need to allocate to split an old_order entry
into multiple entries, each of size new_order. The test suite checks that
we allocated exactly the right number of nodes; neither too many (checked
by rtp->nr == 0), nor too few (checked by comparing nr_allocated before
and after the call to radix_tree_split()).
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
include/linux/radix-tree.h | 1 +
lib/radix-tree.c | 24 +++++++++++++++++++++++-
tools/testing/radix-tree/multiorder.c | 32 ++++++++++++++++++++++++++++++--
tools/testing/radix-tree/test.h | 5 +++++
4 files changed, 59 insertions(+), 3 deletions(-)
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index f5518f1..8ffb051 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -319,6 +319,7 @@ static inline void radix_tree_preload_end(void)
preempt_enable();
}
+int radix_tree_split_preload(unsigned old_order, unsigned new_order, gfp_t);
int radix_tree_split(struct radix_tree_root *, unsigned long index,
unsigned new_order);
int radix_tree_join(struct radix_tree_root *, unsigned long index,
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index eaf0f353..6d73575 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -344,7 +344,7 @@ radix_tree_node_free(struct radix_tree_node *node)
* To make use of this facility, the radix tree must be initialised without
* __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE().
*/
-static int __radix_tree_preload(gfp_t gfp_mask, int nr)
+static int __radix_tree_preload(gfp_t gfp_mask, unsigned nr)
{
struct radix_tree_preload *rtp;
struct radix_tree_node *node;
@@ -410,6 +410,28 @@ int radix_tree_maybe_preload(gfp_t gfp_mask)
}
EXPORT_SYMBOL(radix_tree_maybe_preload);
+#ifdef CONFIG_RADIX_TREE_MULTIORDER
+/*
+ * Preload with enough objects to ensure that we can split a single entry
+ * of order @old_order into many entries of size @new_order
+ */
+int radix_tree_split_preload(unsigned int old_order, unsigned int new_order,
+ gfp_t gfp_mask)
+{
+ unsigned top = 1 << (old_order % RADIX_TREE_MAP_SHIFT);
+ unsigned layers = (old_order / RADIX_TREE_MAP_SHIFT) -
+ (new_order / RADIX_TREE_MAP_SHIFT);
+ unsigned nr = 0;
+
+ WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask));
+ BUG_ON(new_order >= old_order);
+
+ while (layers--)
+ nr = nr * RADIX_TREE_MAP_SIZE + 1;
+ return __radix_tree_preload(gfp_mask, top * nr);
+}
+#endif
+
/*
* The same as function above, but preload number of nodes required to insert
* (1 << order) continuous naturally-aligned elements.
diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index d9e8155..25e0463 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -356,18 +356,46 @@ static void multiorder_join(void)
}
}
+static void check_mem(unsigned old_order, unsigned new_order, unsigned alloc)
+{
+ struct radix_tree_preload *rtp = &radix_tree_preloads;
+ if (rtp->nr != 0)
+ printf("split(%u %u) remaining %u\n", old_order, new_order,
+ rtp->nr);
+ /*
+ * Can't check for equality here as some nodes may have been
+ * RCU-freed while we ran. But we should never finish with more
+ * nodes allocated since they should have all been preloaded.
+ */
+ if (nr_allocated > alloc)
+ printf("split(%u %u) allocated %u %u\n", old_order, new_order,
+ alloc, nr_allocated);
+}
+
static void __multiorder_split(int old_order, int new_order)
{
- RADIX_TREE(tree, GFP_KERNEL);
+ RADIX_TREE(tree, GFP_ATOMIC);
void **slot;
struct radix_tree_iter iter;
+ unsigned alloc;
+
+ radix_tree_preload(GFP_KERNEL);
+ assert(item_insert_order(&tree, 0, old_order) == 0);
+ radix_tree_preload_end();
+
+ /* Wipe out the preloaded cache or it'll confuse check_mem() */
+ radix_tree_callback(NULL, CPU_DEAD, NULL);
- item_insert_order(&tree, 0, old_order);
radix_tree_tag_set(&tree, 0, 2);
+
+ radix_tree_split_preload(old_order, new_order, GFP_KERNEL);
+ alloc = nr_allocated;
radix_tree_split(&tree, 0, new_order);
+ check_mem(old_order, new_order, alloc);
radix_tree_for_each_slot(slot, &tree, &iter, 0) {
radix_tree_replace_slot(slot, item_create(iter.index));
}
+ radix_tree_preload_end();
item_kill_tree(&tree);
}
diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h
index f2dc35f..33d2b6b 100644
--- a/tools/testing/radix-tree/test.h
+++ b/tools/testing/radix-tree/test.h
@@ -49,3 +49,8 @@ unsigned long node_maxindex(struct radix_tree_node *);
unsigned long shift_maxindex(unsigned int shift);
int radix_tree_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu);
+struct radix_tree_preload {
+ unsigned nr;
+ struct radix_tree_node *nodes;
+};
+extern struct radix_tree_preload radix_tree_preloads;
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 19/29] radix tree test suite: iteration test misuses RCU |
| Message-ID | <sEgSm-rg-43@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <mawilcox@microsoft.com>
Each thread needs to register itself with RCU, otherwise the reading
thread's read lock has no effect and the freeing thread will free the
memory in the tree without waiting for the read lock to be dropped.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
tools/testing/radix-tree/iteration_check.c | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)
diff --git a/tools/testing/radix-tree/iteration_check.c b/tools/testing/radix-tree/iteration_check.c
index 11d570c..df71cb8 100644
--- a/tools/testing/radix-tree/iteration_check.c
+++ b/tools/testing/radix-tree/iteration_check.c
@@ -29,6 +29,8 @@ static void *add_entries_fn(void *arg)
{
int pgoff;
+ rcu_register_thread();
+
while (!test_complete) {
for (pgoff = 0; pgoff < 100; pgoff++) {
pthread_mutex_lock(&tree_lock);
@@ -38,6 +40,8 @@ static void *add_entries_fn(void *arg)
}
}
+ rcu_unregister_thread();
+
return NULL;
}
@@ -53,6 +57,8 @@ static void *tagged_iteration_fn(void *arg)
struct radix_tree_iter iter;
void **slot;
+ rcu_register_thread();
+
while (!test_complete) {
rcu_read_lock();
radix_tree_for_each_tagged(slot, &tree, &iter, 0, TAG) {
@@ -72,12 +78,18 @@ static void *tagged_iteration_fn(void *arg)
continue;
}
- if (rand_r(&seeds[0]) % 50 == 0)
+ if (rand_r(&seeds[0]) % 50 == 0) {
slot = radix_tree_iter_next(&iter);
+ rcu_read_unlock();
+ rcu_barrier();
+ rcu_read_lock();
+ }
}
rcu_read_unlock();
}
+ rcu_unregister_thread();
+
return NULL;
}
@@ -93,6 +105,8 @@ static void *untagged_iteration_fn(void *arg)
struct radix_tree_iter iter;
void **slot;
+ rcu_register_thread();
+
while (!test_complete) {
rcu_read_lock();
radix_tree_for_each_slot(slot, &tree, &iter, 0) {
@@ -112,12 +126,18 @@ static void *untagged_iteration_fn(void *arg)
continue;
}
- if (rand_r(&seeds[1]) % 50 == 0)
+ if (rand_r(&seeds[1]) % 50 == 0) {
slot = radix_tree_iter_next(&iter);
+ rcu_read_unlock();
+ rcu_barrier();
+ rcu_read_lock();
+ }
}
rcu_read_unlock();
}
+ rcu_unregister_thread();
+
return NULL;
}
@@ -127,6 +147,8 @@ static void *untagged_iteration_fn(void *arg)
*/
static void *remove_entries_fn(void *arg)
{
+ rcu_register_thread();
+
while (!test_complete) {
int pgoff;
@@ -137,6 +159,8 @@ static void *remove_entries_fn(void *arg)
pthread_mutex_unlock(&tree_lock);
}
+ rcu_unregister_thread();
+
return NULL;
}
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 18/29] btrfs: Fix race in btrfs_free_dummy_fs_info() |
| Message-ID | <sEgSn-rg-51@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <mawilcox@microsoft.com> We drop the lock which protects the radix tree, so we must call radix_tree_iter_next() in order to avoid a modification to the tree invalidating the iterator state. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> --- fs/btrfs/tests/btrfs-tests.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c index bf62ad9..73076a0 100644 --- a/fs/btrfs/tests/btrfs-tests.c +++ b/fs/btrfs/tests/btrfs-tests.c @@ -162,6 +162,7 @@ void btrfs_free_dummy_fs_info(struct btrfs_fs_info *fs_info) slot = radix_tree_iter_retry(&iter); continue; } + slot = radix_tree_iter_next(&iter); spin_unlock(&fs_info->buffer_lock); free_extent_buffer_stale(eb); spin_lock(&fs_info->buffer_lock); -- 2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 10/29] radix-tree: Add radix_tree_join |
| Message-ID | <sEgSn-rg-53@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <willy@linux.intel.com>
This new function allows for the replacement of many smaller entries in
the radix tree with one larger multiorder entry. From the point of view
of an RCU walker, they may see a mixture of the smaller entries and the
large entry during the same walk, but they will never see NULL for an
index which was populated before the join.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
include/linux/radix-tree.h | 2 +
lib/radix-tree.c | 159 +++++++++++++++++++++++++++-------
tools/testing/radix-tree/multiorder.c | 32 +++++++
3 files changed, 163 insertions(+), 30 deletions(-)
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index af3581b..1efd81f 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -319,6 +319,8 @@ static inline void radix_tree_preload_end(void)
preempt_enable();
}
+int radix_tree_join(struct radix_tree_root *, unsigned long index,
+ unsigned new_order, void *);
/**
* struct radix_tree_iter - radix tree iterator state
*
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 8e6d552..6a76252 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -314,18 +314,14 @@ static void radix_tree_node_rcu_free(struct rcu_head *head)
{
struct radix_tree_node *node =
container_of(head, struct radix_tree_node, rcu_head);
- int i;
/*
- * must only free zeroed nodes into the slab. radix_tree_shrink
- * can leave us with a non-NULL entry in the first slot, so clear
- * that here to make sure.
+ * Must only free zeroed nodes into the slab. We can be left with
+ * non-NULL entries by radix_tree_free_nodes, so clear the entries
+ * and tags here.
*/
- for (i = 0; i < RADIX_TREE_MAX_TAGS; i++)
- tag_clear(node, i, 0);
-
- node->slots[0] = NULL;
- node->count = 0;
+ memset(node->slots, 0, sizeof(node->slots));
+ memset(node->tags, 0, sizeof(node->tags));
kmem_cache_free(radix_tree_node_cachep, node);
}
@@ -563,14 +559,14 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
shift = radix_tree_load_root(root, &child, &maxindex);
/* Make sure the tree is high enough. */
+ if (order > 0 && max == ((1UL << order) - 1))
+ max++;
if (max > maxindex) {
int error = radix_tree_extend(root, max, shift);
if (error < 0)
return error;
shift = error;
child = root->rnode;
- if (order == shift)
- shift += RADIX_TREE_MAP_SHIFT;
}
while (shift > order) {
@@ -582,6 +578,7 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
return -ENOMEM;
child->shift = shift;
child->offset = offset;
+ child->count = 0;
child->parent = node;
rcu_assign_pointer(*slot, node_to_entry(child));
if (node)
@@ -595,31 +592,113 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
slot = &node->slots[offset];
}
+ if (nodep)
+ *nodep = node;
+ if (slotp)
+ *slotp = slot;
+ return 0;
+}
+
#ifdef CONFIG_RADIX_TREE_MULTIORDER
- /* Insert pointers to the canonical entry */
- if (order > shift) {
- unsigned i, n = 1 << (order - shift);
+/*
+ * Free any nodes below this node. The tree is presumed to not need
+ * shrinking, and any user data in the tree is presumed to not need a
+ * destructor called on it. If we need to add a destructor, we can
+ * add that functionality later. Note that we may not clear tags or
+ * slots from the tree as an RCU walker may still have a pointer into
+ * this subtree. We could replace the entries with RADIX_TREE_RETRY,
+ * but we'll still have to clear those in rcu_free.
+ */
+static void radix_tree_free_nodes(struct radix_tree_node *node)
+{
+ unsigned offset = 0;
+ struct radix_tree_node *child = entry_to_node(node);
+
+ for (;;) {
+ void *entry = child->slots[offset];
+ if (radix_tree_is_internal_node(entry) &&
+ !is_sibling_entry(child, entry)) {
+ child = entry_to_node(entry);
+ offset = 0;
+ continue;
+ }
+ offset++;
+ while (offset == RADIX_TREE_MAP_SIZE) {
+ struct radix_tree_node *old = child;
+ offset = child->offset + 1;
+ child = child->parent;
+ radix_tree_node_free(old);
+ if (old == entry_to_node(node))
+ return;
+ }
+ }
+}
+
+static inline int insert_entries(struct radix_tree_node *node, void **slot,
+ void *ptr, unsigned order, bool replace)
+{
+ struct radix_tree_node *child;
+ unsigned i, n, tag, offset, tags = 0;
+
+ if (node) {
+ n = 1 << (order - node->shift);
+ offset = get_slot_offset(node, slot);
+ } else {
+ n = 1;
+ offset = 0;
+ }
+
+ if (n > 1) {
offset = offset & ~(n - 1);
slot = &node->slots[offset];
- child = node_to_entry(slot);
- for (i = 0; i < n; i++) {
- if (slot[i])
+ }
+ child = node_to_entry(slot);
+
+ for (i = 0; i < n; i++) {
+ if (slot[i]) {
+ if (replace) {
+ node->count--;
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
+ if (tag_get(node, tag, offset + i))
+ tags |= 1 << tag;
+ } else
return -EEXIST;
}
+ }
- for (i = 1; i < n; i++) {
+ for (i = 0; i < n; i++) {
+ struct radix_tree_node *old = slot[i];
+ if (i) {
rcu_assign_pointer(slot[i], child);
- node->count++;
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
+ if (tags & (1 << tag))
+ tag_clear(node, tag, offset + i);
+ } else {
+ rcu_assign_pointer(slot[i], ptr);
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
+ if (tags & (1 << tag))
+ tag_set(node, tag, offset);
}
+ if (radix_tree_is_internal_node(old) &&
+ !is_sibling_entry(node, old))
+ radix_tree_free_nodes(old);
}
-#endif
-
- if (nodep)
- *nodep = node;
- if (slotp)
- *slotp = slot;
- return 0;
+ if (node)
+ node->count += n;
+ return n;
+}
+#else
+static inline int insert_entries(struct radix_tree_node *node, void **slot,
+ void *ptr, unsigned order, bool replace)
+{
+ if (*slot)
+ return -EEXIST;
+ rcu_assign_pointer(*slot, ptr);
+ if (node)
+ node->count++;
+ return 1;
}
+#endif
/**
* __radix_tree_insert - insert into a radix tree
@@ -642,13 +721,13 @@ int __radix_tree_insert(struct radix_tree_root *root, unsigned long index,
error = __radix_tree_create(root, index, order, &node, &slot);
if (error)
return error;
- if (*slot != NULL)
- return -EEXIST;
- rcu_assign_pointer(*slot, item);
+
+ error = insert_entries(node, slot, item, order, false);
+ if (error < 0)
+ return error;
if (node) {
unsigned offset = get_slot_offset(node, slot);
- node->count++;
BUG_ON(tag_get(node, 0, offset));
BUG_ON(tag_get(node, 1, offset));
BUG_ON(tag_get(node, 2, offset));
@@ -746,6 +825,26 @@ void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index)
}
EXPORT_SYMBOL(radix_tree_lookup);
+#ifdef CONFIG_RADIX_TREE_MULTIORDER
+int radix_tree_join(struct radix_tree_root *root, unsigned long index,
+ unsigned order, void *item)
+{
+ struct radix_tree_node *node;
+ void **slot;
+ int error;
+
+ BUG_ON(radix_tree_is_internal_node(item));
+
+ error = __radix_tree_create(root, index, order, &node, &slot);
+ if (!error)
+ error = insert_entries(node, slot, item, order, true);
+ if (error > 0)
+ error = 0;
+
+ return error;
+}
+#endif
+
/**
* radix_tree_tag_set - set a tag on a radix tree node
* @root: radix tree root
diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index 05d7bc4..4c66acc 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -325,6 +325,37 @@ void multiorder_tagged_iteration(void)
item_kill_tree(&tree);
}
+static void __multiorder_join(unsigned long index,
+ unsigned order1, unsigned order2)
+{
+ unsigned long loc;
+ void *item, *item2 = item_create(index + 1);
+ RADIX_TREE(tree, GFP_KERNEL);
+
+ item_insert_order(&tree, index, order2);
+ item = radix_tree_lookup(&tree, index);
+ radix_tree_join(&tree, index + 1, order1, item2);
+ loc = radix_tree_locate_item(&tree, item);
+ if (loc == -1)
+ free(item);
+ item = radix_tree_lookup(&tree, index + 1);
+ assert(item == item2);
+ item_kill_tree(&tree);
+}
+
+static void multiorder_join(void)
+{
+ int i, j, idx;
+
+ for (idx = 0; idx < 1024; idx = idx * 2 + 3) {
+ for (i = 1; i < 15; i++) {
+ for (j = 0; j < i; j++) {
+ __multiorder_join(idx, i, j);
+ }
+ }
+ }
+}
+
void multiorder_checks(void)
{
int i;
@@ -342,4 +373,5 @@ void multiorder_checks(void)
multiorder_tag_tests();
multiorder_iteration();
multiorder_tagged_iteration();
+ multiorder_join();
}
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 23/29] idr: Add ida_is_empty |
| Message-ID | <sEgSm-rg-23@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <willy@linux.intel.com>
Two of the USB Gadgets were poking around in the internals of struct ida
in order to determine if it is empty. Add the appropriate abstraction.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
drivers/usb/gadget/function/f_hid.c | 6 +++---
drivers/usb/gadget/function/f_printer.c | 6 +++---
include/linux/idr.h | 5 +++++
3 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index e2966f8..b9b04fc 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -840,7 +840,7 @@ static void hidg_free_inst(struct usb_function_instance *f)
mutex_lock(&hidg_ida_lock);
hidg_put_minor(opts->minor);
- if (idr_is_empty(&hidg_ida.idr))
+ if (ida_is_empty(&hidg_ida))
ghid_cleanup();
mutex_unlock(&hidg_ida_lock);
@@ -866,7 +866,7 @@ static struct usb_function_instance *hidg_alloc_inst(void)
mutex_lock(&hidg_ida_lock);
- if (idr_is_empty(&hidg_ida.idr)) {
+ if (ida_is_empty(&hidg_ida)) {
status = ghid_setup(NULL, HIDG_MINORS);
if (status) {
ret = ERR_PTR(status);
@@ -879,7 +879,7 @@ static struct usb_function_instance *hidg_alloc_inst(void)
if (opts->minor < 0) {
ret = ERR_PTR(opts->minor);
kfree(opts);
- if (idr_is_empty(&hidg_ida.idr))
+ if (ida_is_empty(&hidg_ida))
ghid_cleanup();
goto unlock;
}
diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
index 0de36cd..8054da9 100644
--- a/drivers/usb/gadget/function/f_printer.c
+++ b/drivers/usb/gadget/function/f_printer.c
@@ -1265,7 +1265,7 @@ static void gprinter_free_inst(struct usb_function_instance *f)
mutex_lock(&printer_ida_lock);
gprinter_put_minor(opts->minor);
- if (idr_is_empty(&printer_ida.idr))
+ if (ida_is_empty(&printer_ida))
gprinter_cleanup();
mutex_unlock(&printer_ida_lock);
@@ -1289,7 +1289,7 @@ static struct usb_function_instance *gprinter_alloc_inst(void)
mutex_lock(&printer_ida_lock);
- if (idr_is_empty(&printer_ida.idr)) {
+ if (ida_is_empty(&printer_ida)) {
status = gprinter_setup(PRINTER_MINORS);
if (status) {
ret = ERR_PTR(status);
@@ -1302,7 +1302,7 @@ static struct usb_function_instance *gprinter_alloc_inst(void)
if (opts->minor < 0) {
ret = ERR_PTR(opts->minor);
kfree(opts);
- if (idr_is_empty(&printer_ida.idr))
+ if (ida_is_empty(&printer_ida))
gprinter_cleanup();
goto unlock;
}
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 083d61e..3639a28 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -195,6 +195,11 @@ static inline int ida_get_new(struct ida *ida, int *p_id)
return ida_get_new_above(ida, 0, p_id);
}
+static inline bool ida_is_empty(struct ida *ida)
+{
+ return idr_is_empty(&ida->idr);
+}
+
void __init idr_init_cache(void);
#endif /* __IDR_H__ */
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 22/29] radix-tree: Delete radix_tree_range_tag_if_tagged() |
| Message-ID | <sEgSn-rg-55@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <mawilcox@microsoft.com>
This is an exceptionally complicated function with just one caller
(tag_pages_for_writeback). We devote a large portion of the runtime
of the test suite to testing this one function which has one caller.
By introducing the new function radix_tree_iter_tag_set(), we
can eliminate all of the complexity while keeping the performance.
The caller can now use a fairly standard radix_tree_for_each() loop,
and it doesn't need to worry about tricksy things like 'start' wrapping.
The test suite continues to spend a large amount of time investigating
this function, but now it's testing the underlying primitives such as
radix_tree_iter_next() and the radix_tree_for_each_tagged() iterator
which are also used by other parts of the kernel.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
---
include/linux/radix-tree.h | 74 ++++++++++-----------
lib/radix-tree.c | 114 +++++----------------------------
mm/page-writeback.c | 28 +++++---
tools/testing/radix-tree/main.c | 12 ++--
tools/testing/radix-tree/multiorder.c | 13 ++--
tools/testing/radix-tree/regression2.c | 3 +-
tools/testing/radix-tree/tag_check.c | 4 +-
tools/testing/radix-tree/test.c | 25 ++++++++
tools/testing/radix-tree/test.h | 3 +
9 files changed, 113 insertions(+), 163 deletions(-)
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index 57bf635..ca4eea1 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -124,6 +124,41 @@ static inline bool radix_tree_empty(struct radix_tree_root *root)
}
/**
+ * struct radix_tree_iter - radix tree iterator state
+ *
+ * @index: index of current slot
+ * @next_index: one beyond the last index for this chunk
+ * @tags: bit-mask for tag-iterating
+ * @node: node that contains current slot
+ * @shift: shift for the node that holds our slots
+ *
+ * This radix tree iterator works in terms of "chunks" of slots. A chunk is a
+ * subinterval of slots contained within one radix tree leaf node. It is
+ * described by a pointer to its first slot and a struct radix_tree_iter
+ * which holds the chunk's position in the tree and its size. For tagged
+ * iteration radix_tree_iter also holds the slots' bit-mask for one chosen
+ * radix tree tag.
+ */
+struct radix_tree_iter {
+ unsigned long index;
+ unsigned long next_index;
+ unsigned long tags;
+ struct radix_tree_node *node;
+#ifdef CONFIG_RADIX_TREE_MULTIORDER
+ unsigned int shift;
+#endif
+};
+
+static inline unsigned int iter_shift(struct radix_tree_iter *iter)
+{
+#ifdef CONFIG_RADIX_TREE_MULTIORDER
+ return iter->shift;
+#else
+ return 0;
+#endif
+}
+
+/**
* Radix-tree synchronization
*
* The radix-tree API requires that users provide all synchronisation (with
@@ -293,6 +328,8 @@ void *radix_tree_tag_clear(struct radix_tree_root *root,
unsigned long index, unsigned int tag);
int radix_tree_tag_get(struct radix_tree_root *root,
unsigned long index, unsigned int tag);
+void radix_tree_iter_tag_set(struct radix_tree_root *root,
+ const struct radix_tree_iter *iter, unsigned int tag);
unsigned int
radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
unsigned long first_index, unsigned int max_items,
@@ -301,10 +338,6 @@ unsigned int
radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,
unsigned long first_index, unsigned int max_items,
unsigned int tag);
-unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
- unsigned long *first_indexp, unsigned long last_index,
- unsigned long nr_to_tag,
- unsigned int fromtag, unsigned int totag);
int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);
static inline void radix_tree_preload_end(void)
@@ -318,39 +351,6 @@ int radix_tree_split(struct radix_tree_root *, unsigned long index,
int radix_tree_join(struct radix_tree_root *, unsigned long index,
unsigned new_order, void *);
-/**
- * struct radix_tree_iter - radix tree iterator state
- *
- * @index: index of current slot
- * @next_index: one beyond the last index for this chunk
- * @tags: bit-mask for tag-iterating
- * @shift: shift for the node that holds our slots
- *
- * This radix tree iterator works in terms of "chunks" of slots. A chunk is a
- * subinterval of slots contained within one radix tree leaf node. It is
- * described by a pointer to its first slot and a struct radix_tree_iter
- * which holds the chunk's position in the tree and its size. For tagged
- * iteration radix_tree_iter also holds the slots' bit-mask for one chosen
- * radix tree tag.
- */
-struct radix_tree_iter {
- unsigned long index;
- unsigned long next_index;
- unsigned long tags;
-#ifdef CONFIG_RADIX_TREE_MULTIORDER
- unsigned int shift;
-#endif
-};
-
-static inline unsigned int iter_shift(struct radix_tree_iter *iter)
-{
-#ifdef CONFIG_RADIX_TREE_MULTIORDER
- return iter->shift;
-#else
- return 0;
-#endif
-}
-
#define RADIX_TREE_ITER_TAG_MASK 0x00FF /* tag index in lower byte */
#define RADIX_TREE_ITER_TAGGED 0x0100 /* lookup tagged slots */
#define RADIX_TREE_ITER_CONTIG 0x0200 /* stop at first hole */
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 7e70ac9..c8ef657 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1049,6 +1049,20 @@ static void node_tag_set(struct radix_tree_root *root,
}
/**
+ * radix_tree_iter_tag_set - set a tag on the current iterator entry
+ *
+ * @root: radix tree root
+ * @iter: iterator state
+ * @tag: tag to set
+ */
+void radix_tree_iter_tag_set(struct radix_tree_root *root,
+ const struct radix_tree_iter *iter, unsigned int tag)
+{
+ unsigned offset = (iter->index >> iter->shift) & RADIX_TREE_MAP_MASK;
+ node_tag_set(root, iter->node, tag, offset);
+}
+
+/**
* radix_tree_tag_clear - clear a tag on a radix tree node
* @root: radix tree root
* @index: index key
@@ -1176,6 +1190,7 @@ void ** __radix_tree_next_slot(void **slot, struct radix_tree_iter *iter,
if (node == RADIX_TREE_RETRY)
return slot;
node = entry_to_node(node);
+ iter->node = node;
if (flags & RADIX_TREE_ITER_TAGGED) {
unsigned tag_long, tag_bit;
@@ -1275,6 +1290,7 @@ void **radix_tree_next_chunk(struct radix_tree_root *root,
iter->index = index;
iter->next_index = maxindex + 1;
iter->tags = 1;
+ iter->node = NULL;
__set_iter_shift(iter, 0);
return (void **)&root->rnode;
}
@@ -1319,6 +1335,7 @@ void **radix_tree_next_chunk(struct radix_tree_root *root,
/* Update the iterator state */
iter->index = (index &~ node_maxindex(node)) | (offset << node->shift);
iter->next_index = (index | node_maxindex(node)) + 1;
+ iter->node = node;
__set_iter_shift(iter, node->shift);
/* Construct iter->tags bit-mask from node->tags[tag] array */
@@ -1344,103 +1361,6 @@ void **radix_tree_next_chunk(struct radix_tree_root *root,
EXPORT_SYMBOL(radix_tree_next_chunk);
/**
- * radix_tree_range_tag_if_tagged - for each item in given range set given
- * tag if item has another tag set
- * @root: radix tree root
- * @first_indexp: pointer to a starting index of a range to scan
- * @last_index: last index of a range to scan
- * @nr_to_tag: maximum number items to tag
- * @iftag: tag index to test
- * @settag: tag index to set if tested tag is set
- *
- * This function scans range of radix tree from first_index to last_index
- * (inclusive). For each item in the range if iftag is set, the function sets
- * also settag. The function stops either after tagging nr_to_tag items or
- * after reaching last_index.
- *
- * The tags must be set from the leaf level only and propagated back up the
- * path to the root. We must do this so that we resolve the full path before
- * setting any tags on intermediate nodes. If we set tags as we descend, then
- * we can get to the leaf node and find that the index that has the iftag
- * set is outside the range we are scanning. This reults in dangling tags and
- * can lead to problems with later tag operations (e.g. livelocks on lookups).
- *
- * The function returns the number of leaves where the tag was set and sets
- * *first_indexp to the first unscanned index.
- * WARNING! *first_indexp can wrap if last_index is ULONG_MAX. Caller must
- * be prepared to handle that.
- */
-unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
- unsigned long *first_indexp, unsigned long last_index,
- unsigned long nr_to_tag,
- unsigned int iftag, unsigned int settag)
-{
- struct radix_tree_node *node, *child;
- unsigned long maxindex;
- unsigned long tagged = 0;
- unsigned long index = *first_indexp;
-
- radix_tree_load_root(root, &child, &maxindex);
- last_index = min(last_index, maxindex);
- if (index > last_index)
- return 0;
- if (!nr_to_tag)
- return 0;
- if (!root_tag_get(root, iftag)) {
- *first_indexp = last_index + 1;
- return 0;
- }
- if (!radix_tree_is_internal_node(child)) {
- *first_indexp = last_index + 1;
- root_tag_set(root, settag);
- return 1;
- }
-
- node = entry_to_node(child);
-
- for (;;) {
- unsigned offset = radix_tree_descend(node, &child, index);
- if (!child)
- goto next;
- if (!tag_get(node, iftag, offset))
- goto next;
- /* Sibling slots never have tags set on them */
- if (radix_tree_is_internal_node(child)) {
- node = entry_to_node(child);
- continue;
- }
-
- tagged++;
- node_tag_set(root, node, settag, offset);
- next:
- /* Go to next entry in node */
- index = ((index >> node->shift) + 1) << node->shift;
- /* Overflow can happen when last_index is ~0UL... */
- if (index > last_index || !index)
- break;
- offset = (index >> node->shift) & RADIX_TREE_MAP_MASK;
- while (offset == 0) {
- /*
- * We've fully scanned this node. Go up. Because
- * last_index is guaranteed to be in the tree, what
- * we do below cannot wander astray.
- */
- node = node->parent;
- offset = (index >> node->shift) & RADIX_TREE_MAP_MASK;
- }
- if (is_sibling_entry(node, node->slots[offset]))
- goto next;
- if (tagged >= nr_to_tag)
- break;
- }
-
- *first_indexp = index;
-
- return tagged;
-}
-EXPORT_SYMBOL(radix_tree_range_tag_if_tagged);
-
-/**
* radix_tree_gang_lookup - perform multiple lookup on a radix tree
* @root: radix tree root
* @results: where the results of the lookup are placed
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 439cc63..c593715 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2105,18 +2105,26 @@ void tag_pages_for_writeback(struct address_space *mapping,
pgoff_t start, pgoff_t end)
{
#define WRITEBACK_TAG_BATCH 4096
- unsigned long tagged;
-
- do {
- spin_lock_irq(&mapping->tree_lock);
- tagged = radix_tree_range_tag_if_tagged(&mapping->page_tree,
- &start, end, WRITEBACK_TAG_BATCH,
- PAGECACHE_TAG_DIRTY, PAGECACHE_TAG_TOWRITE);
+ unsigned long tagged = 0;
+ struct radix_tree_iter iter;
+ void **slot;
+
+ spin_lock_irq(&mapping->tree_lock);
+ radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter, start,
+ PAGECACHE_TAG_DIRTY) {
+ if (iter.index > end)
+ break;
+ radix_tree_iter_tag_set(&mapping->page_tree, &iter,
+ PAGECACHE_TAG_TOWRITE);
+ tagged++;
+ if ((tagged % WRITEBACK_TAG_BATCH) != 0)
+ continue;
+ slot = radix_tree_iter_next(slot, &iter);
spin_unlock_irq(&mapping->tree_lock);
- WARN_ON_ONCE(tagged > WRITEBACK_TAG_BATCH);
cond_resched();
- /* We check 'start' to handle wrapping when end == ~0UL */
- } while (tagged >= WRITEBACK_TAG_BATCH && start);
+ spin_lock_irq(&mapping->tree_lock);
+ }
+ spin_unlock_irq(&mapping->tree_lock);
}
EXPORT_SYMBOL(tag_pages_for_writeback);
diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c
index 93a77f9..7d14812 100644
--- a/tools/testing/radix-tree/main.c
+++ b/tools/testing/radix-tree/main.c
@@ -205,8 +205,7 @@ void copy_tag_check(void)
}
// printf("\ncopying tags...\n");
- cur = start;
- tagged = radix_tree_range_tag_if_tagged(&tree, &cur, end, ITEMS, 0, 1);
+ tagged = tag_tagged_items(&tree, start, end, ITEMS, 0, 1);
// printf("checking copied tags\n");
assert(tagged == count);
@@ -214,16 +213,13 @@ void copy_tag_check(void)
/* Copy tags in several rounds */
// printf("\ncopying tags...\n");
- cur = start;
- do {
- tmp = rand() % (count/10+2);
- tagged = radix_tree_range_tag_if_tagged(&tree, &cur, end, tmp, 0, 2);
- } while (tmp == tagged);
+ tmp = rand() % (count / 10 + 2);
+ tagged = tag_tagged_items(&tree, start, end, tmp, 0, 2);
+ assert(tagged == count);
// printf("%lu %lu %lu\n", tagged, tmp, count);
// printf("checking copied tags\n");
check_copied_tags(&tree, start, end, idx, ITEMS, 0, 2);
- assert(tagged < tmp);
verify_tag_consistency(&tree, 0);
verify_tag_consistency(&tree, 1);
verify_tag_consistency(&tree, 2);
diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index 400de5c..6a0287d 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -26,7 +26,6 @@ static void __multiorder_tag_test(int index, int order)
{
RADIX_TREE(tree, GFP_KERNEL);
int base, err, i;
- unsigned long first = 0;
/* our canonical entry */
base = index & ~((1 << order) - 1);
@@ -60,7 +59,7 @@ static void __multiorder_tag_test(int index, int order)
assert(!radix_tree_tag_get(&tree, i, 1));
}
- assert(radix_tree_range_tag_if_tagged(&tree, &first, ~0UL, 10, 0, 1) == 1);
+ assert(tag_tagged_items(&tree, 0, ~0UL, 10, 0, 1) == 1);
assert(radix_tree_tag_clear(&tree, index, 0));
for_each_index(i, base, order) {
@@ -252,7 +251,6 @@ void multiorder_tagged_iteration(void)
RADIX_TREE(tree, GFP_KERNEL);
struct radix_tree_iter iter;
void **slot;
- unsigned long first = 0;
int i, j;
printf("Multiorder tagged iteration test\n");
@@ -297,8 +295,8 @@ void multiorder_tagged_iteration(void)
}
}
- radix_tree_range_tag_if_tagged(&tree, &first, ~0UL,
- MT_NUM_ENTRIES, 1, 2);
+ assert(tag_tagged_items(&tree, 0, ~0UL, TAG_ENTRIES, 1, 2) ==
+ TAG_ENTRIES);
for (j = 0; j < 256; j++) {
int mask, k;
@@ -325,9 +323,8 @@ void multiorder_tagged_iteration(void)
}
}
- first = 1;
- radix_tree_range_tag_if_tagged(&tree, &first, ~0UL,
- MT_NUM_ENTRIES, 1, 0);
+ assert(tag_tagged_items(&tree, 1, ~0UL, MT_NUM_ENTRIES * 2, 1, 0)
+ == TAG_ENTRIES);
i = 0;
radix_tree_for_each_tagged(slot, &tree, &iter, 0, 0) {
assert(iter.index == tag_index[i]);
diff --git a/tools/testing/radix-tree/regression2.c b/tools/testing/radix-tree/regression2.c
index 63bf347..5cd2c0f 100644
--- a/tools/testing/radix-tree/regression2.c
+++ b/tools/testing/radix-tree/regression2.c
@@ -50,6 +50,7 @@
#include <stdio.h>
#include "regression.h"
+#include "test.h"
#define PAGECACHE_TAG_DIRTY 0
#define PAGECACHE_TAG_WRITEBACK 1
@@ -90,7 +91,7 @@ void regression2_test(void)
/* 1. */
start = 0;
end = max_slots - 2;
- radix_tree_range_tag_if_tagged(&mt_tree, &start, end, 1,
+ tag_tagged_items(&mt_tree, start, end, 1,
PAGECACHE_TAG_DIRTY, PAGECACHE_TAG_TOWRITE);
/* 2. */
diff --git a/tools/testing/radix-tree/tag_check.c b/tools/testing/radix-tree/tag_check.c
index 186f6e4..b047b2d 100644
--- a/tools/testing/radix-tree/tag_check.c
+++ b/tools/testing/radix-tree/tag_check.c
@@ -23,7 +23,7 @@ __simple_checks(struct radix_tree_root *tree, unsigned long index, int tag)
item_tag_set(tree, index, tag);
ret = item_tag_get(tree, index, tag);
assert(ret != 0);
- ret = radix_tree_range_tag_if_tagged(tree, &first, ~0UL, 10, tag, !tag);
+ ret = tag_tagged_items(tree, first, ~0UL, 10, tag, !tag);
assert(ret == 1);
ret = item_tag_get(tree, index, !tag);
assert(ret != 0);
@@ -320,7 +320,7 @@ static void single_check(void)
assert(ret == 0);
verify_tag_consistency(&tree, 0);
verify_tag_consistency(&tree, 1);
- ret = radix_tree_range_tag_if_tagged(&tree, &first, 10, 10, 0, 1);
+ ret = tag_tagged_items(&tree, first, 10, 10, 0, 1);
assert(ret == 1);
ret = radix_tree_gang_lookup_tag(&tree, (void **)items, 0, BATCH, 1);
assert(ret == 1);
diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c
index a68ed3b..322c34b 100644
--- a/tools/testing/radix-tree/test.c
+++ b/tools/testing/radix-tree/test.c
@@ -142,6 +142,31 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start,
assert(nfound == 0);
}
+/* Use the same pattern as tag_pages_for_writeback() in mm/page-writeback.c */
+int tag_tagged_items(struct radix_tree_root *root,
+ unsigned long start, unsigned long end, unsigned batch,
+ unsigned iftag, unsigned thentag)
+{
+ unsigned long tagged = 0;
+ struct radix_tree_iter iter;
+ void **slot;
+
+ if (batch == 0)
+ batch = 1;
+
+ radix_tree_for_each_tagged(slot, root, &iter, start, iftag) {
+ if (iter.index > end)
+ break;
+ radix_tree_iter_tag_set(root, &iter, thentag);
+ tagged++;
+ if ((tagged % batch) != 0)
+ continue;
+ slot = radix_tree_iter_next(slot, &iter);
+ }
+
+ return tagged;
+}
+
/* Use the same pattern as find_swap_entry() in mm/shmem.c */
unsigned long find_item(struct radix_tree_root *root, void *item)
{
diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h
index ccdd3c1..1faf0a3 100644
--- a/tools/testing/radix-tree/test.h
+++ b/tools/testing/radix-tree/test.h
@@ -27,6 +27,9 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start,
unsigned long nr, int chunk);
void item_kill_tree(struct radix_tree_root *root);
+int tag_tagged_items(struct radix_tree_root *, unsigned long start,
+ unsigned long end, unsigned batch,
+ unsigned iftag, unsigned thentag);
unsigned long find_item(struct radix_tree_root *, void *item);
void tag_check(void);
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 25/29] rxrpc: Abstract away knowledge of IDR internals |
| Message-ID | <sEgSn-rg-57@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <mawilcox@microsoft.com>
Add idr_get_cursor() / idr_set_cursor() APIs, and remove the rounding
up to IDR_SIZE.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
include/linux/idr.h | 26 ++++++++++++++++++++++++++
net/rxrpc/af_rxrpc.c | 11 ++++++-----
net/rxrpc/conn_client.c | 4 ++--
3 files changed, 34 insertions(+), 7 deletions(-)
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 3639a28..1eb755f 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -56,6 +56,32 @@ struct idr {
#define DEFINE_IDR(name) struct idr name = IDR_INIT(name)
/**
+ * idr_get_cursor - Return the current position of the cyclic allocator
+ * @idr: idr handle
+ *
+ * The value returned is the value that will be next returned from
+ * idr_alloc_cyclic() if it is free (otherwise the search will start from
+ * this position).
+ */
+static inline unsigned int idr_get_cursor(struct idr *idr)
+{
+ return READ_ONCE(idr->cur);
+}
+
+/**
+ * idr_set_cursor - Set the current position of the cyclic allocator
+ * @idr: idr handle
+ * @val: new position
+ *
+ * The next call to idr_alloc_cyclic() will return @val if it is free
+ * (otherwise the search will start from this position).
+ */
+static inline void idr_set_cursor(struct idr *idr, unsigned int val)
+{
+ WRITE_ONCE(idr->cur, val);
+}
+
+/**
* DOC: idr sync
* idr synchronization (stolen from radix-tree.h)
*
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 2d59c9b..5f63f6d 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -762,16 +762,17 @@ static const struct net_proto_family rxrpc_family_ops = {
static int __init af_rxrpc_init(void)
{
int ret = -1;
+ unsigned int tmp;
BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > FIELD_SIZEOF(struct sk_buff, cb));
get_random_bytes(&rxrpc_epoch, sizeof(rxrpc_epoch));
rxrpc_epoch |= RXRPC_RANDOM_EPOCH;
- get_random_bytes(&rxrpc_client_conn_ids.cur,
- sizeof(rxrpc_client_conn_ids.cur));
- rxrpc_client_conn_ids.cur &= 0x3fffffff;
- if (rxrpc_client_conn_ids.cur == 0)
- rxrpc_client_conn_ids.cur = 1;
+ get_random_bytes(&tmp, sizeof(tmp));
+ tmp &= 0x3fffffff;
+ if (tmp == 0)
+ tmp = 1;
+ idr_set_cursor(&rxrpc_client_conn_ids, tmp);
ret = -ENOMEM;
rxrpc_call_jar = kmem_cache_create(
diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
index 60ef960..9706f60 100644
--- a/net/rxrpc/conn_client.c
+++ b/net/rxrpc/conn_client.c
@@ -263,12 +263,12 @@ static bool rxrpc_may_reuse_conn(struct rxrpc_connection *conn)
* times the maximum number of client conns away from the current
* allocation point to try and keep the IDs concentrated.
*/
- id_cursor = READ_ONCE(rxrpc_client_conn_ids.cur);
+ id_cursor = idr_get_cursor(&rxrpc_client_conn_ids);
id = conn->proto.cid >> RXRPC_CIDSHIFT;
distance = id - id_cursor;
if (distance < 0)
distance = -distance;
- limit = round_up(rxrpc_max_client_connections, IDR_SIZE) * 4;
+ limit = rxrpc_max_client_connections * 4;
if (distance > limit)
goto mark_dont_reuse;
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 05/29] radix tree test suite: Make runs more reproducible |
| Message-ID | <sEgSn-rg-69@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <willy@infradead.org>
Instead of reseeding the random number generator every time around the
loop in big_gang_check(), seed it at the beginning of execution. Use
rand_r() and an independent base seed for each thread in iteration_test()
so they don't stomp all over each others state. Since this particular
test depends on the kernel scheduler, the iteration test can't be
reproduced based purely on the random seed, but at least it won't pollute
the other tests.
Print the seed, and allow the seed to be specified so that a run which
hits a problem can be reproduced.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
---
tools/testing/radix-tree/iteration_check.c | 11 +++++++----
tools/testing/radix-tree/main.c | 9 +++++++--
2 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/tools/testing/radix-tree/iteration_check.c b/tools/testing/radix-tree/iteration_check.c
index 9adb8e7..11d570c 100644
--- a/tools/testing/radix-tree/iteration_check.c
+++ b/tools/testing/radix-tree/iteration_check.c
@@ -20,6 +20,7 @@
#define TAG 0
static pthread_mutex_t tree_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_t threads[NUM_THREADS];
+static unsigned int seeds[3];
RADIX_TREE(tree, GFP_KERNEL);
bool test_complete;
@@ -71,7 +72,7 @@ static void *tagged_iteration_fn(void *arg)
continue;
}
- if (rand() % 50 == 0)
+ if (rand_r(&seeds[0]) % 50 == 0)
slot = radix_tree_iter_next(&iter);
}
rcu_read_unlock();
@@ -111,7 +112,7 @@ static void *untagged_iteration_fn(void *arg)
continue;
}
- if (rand() % 50 == 0)
+ if (rand_r(&seeds[1]) % 50 == 0)
slot = radix_tree_iter_next(&iter);
}
rcu_read_unlock();
@@ -129,7 +130,7 @@ static void *remove_entries_fn(void *arg)
while (!test_complete) {
int pgoff;
- pgoff = rand() % 100;
+ pgoff = rand_r(&seeds[2]) % 100;
pthread_mutex_lock(&tree_lock);
item_delete(&tree, pgoff);
@@ -146,9 +147,11 @@ void iteration_test(void)
printf("Running iteration tests for 10 seconds\n");
- srand(time(0));
test_complete = false;
+ for (i = 0; i < 3; i++)
+ seeds[i] = rand();
+
if (pthread_create(&threads[0], NULL, tagged_iteration_fn, NULL)) {
perror("pthread_create");
exit(1);
diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c
index 2930560..5ddec8e 100644
--- a/tools/testing/radix-tree/main.c
+++ b/tools/testing/radix-tree/main.c
@@ -67,7 +67,6 @@ void big_gang_check(bool long_run)
for (i = 0; i < (long_run ? 1000 : 3); i++) {
__big_gang_check();
- srand(time(0));
printf("%d ", i);
fflush(stdout);
}
@@ -329,12 +328,18 @@ int main(int argc, char **argv)
{
bool long_run = false;
int opt;
+ unsigned int seed = time(NULL);
- while ((opt = getopt(argc, argv, "l")) != -1) {
+ while ((opt = getopt(argc, argv, "ls:")) != -1) {
if (opt == 'l')
long_run = true;
+ else if (opt == 's')
+ seed = strtoul(optarg, NULL, 0);
}
+ printf("random seed %u\n", seed);
+ srand(seed);
+
rcu_register_thread();
radix_tree_init();
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 14/29] radix-tree: Move rcu_head into a union with private_list |
| Message-ID | <sEgSn-rg-71@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <willy@infradead.org>
I want to be able to reference node->parent after freeing node.
Currently node->parent is in a union with rcu_head, so it is overwritten
when the node is put on the RCU list. We know that private_list is not
referenced after the node is freed, so it is safe for these two members
to share space.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
---
include/linux/radix-tree.h | 14 ++++----------
lib/radix-tree.c | 1 +
2 files changed, 5 insertions(+), 10 deletions(-)
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index 8ffb051..66fb8c0 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -88,18 +88,12 @@ struct radix_tree_node {
unsigned char shift; /* Bits remaining in each slot */
unsigned char offset; /* Slot offset in parent */
unsigned int count;
+ struct radix_tree_node *parent; /* Used when ascending tree */
+ void *private_data; /* For tree user */
union {
- struct {
- /* Used when ascending tree */
- struct radix_tree_node *parent;
- /* For tree user */
- void *private_data;
- };
- /* Used when freeing node */
- struct rcu_head rcu_head;
+ struct list_head private_list; /* For tree user */
+ struct rcu_head rcu_head; /* Used when freeing node */
};
- /* For tree user */
- struct list_head private_list;
void __rcu *slots[RADIX_TREE_MAP_SIZE];
unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
};
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index e917c56..baf4ba1 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -325,6 +325,7 @@ static void radix_tree_node_rcu_free(struct rcu_head *head)
*/
memset(node->slots, 0, sizeof(node->slots));
memset(node->tags, 0, sizeof(node->tags));
+ INIT_LIST_HEAD(&node->private_list);
kmem_cache_free(radix_tree_node_cachep, node);
}
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 15/29] radix-tree: Create node_tag_set() |
| Message-ID | <sEgSm-rg-11@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <willy@linux.intel.com>
Similar to node_tag_clear(), factor node_tag_set() out of
radix_tree_range_tag_if_tagged().
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
lib/radix-tree.c | 41 +++++++++++++++++++----------------------
1 file changed, 19 insertions(+), 22 deletions(-)
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index baf4ba1..bf1303f 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1028,6 +1028,22 @@ static void node_tag_clear(struct radix_tree_root *root,
root_tag_clear(root, tag);
}
+static void node_tag_set(struct radix_tree_root *root,
+ struct radix_tree_node *node,
+ unsigned int tag, unsigned int offset)
+{
+ while (node) {
+ if (tag_get(node, tag, offset))
+ return;
+ tag_set(node, tag, offset);
+ offset = node->offset;
+ node = node->parent;
+ }
+
+ if (!root_tag_get(root, tag))
+ root_tag_set(root, tag);
+}
+
/**
* radix_tree_tag_clear - clear a tag on a radix tree node
* @root: radix tree root
@@ -1268,7 +1284,7 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
unsigned long nr_to_tag,
unsigned int iftag, unsigned int settag)
{
- struct radix_tree_node *parent, *node, *child;
+ struct radix_tree_node *node, *child;
unsigned long maxindex;
unsigned long tagged = 0;
unsigned long index = *first_indexp;
@@ -1303,22 +1319,8 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
continue;
}
- /* tag the leaf */
tagged++;
- tag_set(node, settag, offset);
-
- /* walk back up the path tagging interior nodes */
- parent = node;
- for (;;) {
- offset = parent->offset;
- parent = parent->parent;
- if (!parent)
- break;
- /* stop if we find a node with the tag already set */
- if (tag_get(parent, settag, offset))
- break;
- tag_set(parent, settag, offset);
- }
+ node_tag_set(root, node, settag, offset);
next:
/* Go to next entry in node */
index = ((index >> node->shift) + 1) << node->shift;
@@ -1340,12 +1342,7 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
if (tagged >= nr_to_tag)
break;
}
- /*
- * We need not to tag the root tag if there is no tag which is set with
- * settag within the range from *first_indexp to last_index.
- */
- if (tagged > 0)
- root_tag_set(root, settag);
+
*first_indexp = index;
return tagged;
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:30 +0100 |
| Subject | [PATCH 27/29] radix tree test suite: Add some more functionality |
| Message-ID | <sEgSn-rg-77@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <willy@linux.intel.com>
IDR needs more functionality from the kernel: kmalloc()/kfree(), and xchg().
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
tools/testing/radix-tree/linux.c | 15 +++++++++++++++
tools/testing/radix-tree/linux/kernel.h | 3 +++
tools/testing/radix-tree/linux/slab.h | 3 +++
3 files changed, 21 insertions(+)
diff --git a/tools/testing/radix-tree/linux.c b/tools/testing/radix-tree/linux.c
index 1f32a16..ff0452e 100644
--- a/tools/testing/radix-tree/linux.c
+++ b/tools/testing/radix-tree/linux.c
@@ -54,6 +54,21 @@ void kmem_cache_free(struct kmem_cache *cachep, void *objp)
free(objp);
}
+void *kmalloc(size_t size, gfp_t gfp)
+{
+ void *ret = malloc(size);
+ uatomic_inc(&nr_allocated);
+ return ret;
+}
+
+void kfree(void *p)
+{
+ if (!p)
+ return;
+ uatomic_dec(&nr_allocated);
+ free(p);
+}
+
struct kmem_cache *
kmem_cache_create(const char *name, size_t size, size_t offset,
unsigned long flags, void (*ctor)(void *))
diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h
index 23e77f5..9b43b49 100644
--- a/tools/testing/radix-tree/linux/kernel.h
+++ b/tools/testing/radix-tree/linux/kernel.h
@@ -8,6 +8,7 @@
#include <limits.h>
#include "../../include/linux/compiler.h"
+#include "../../include/linux/err.h"
#include "../../../include/linux/kconfig.h"
#ifdef BENCHMARK
@@ -58,4 +59,6 @@ static inline int in_interrupt(void)
#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
#define round_down(x, y) ((x) & ~__round_mask(x, y))
+#define xchg(ptr, x) uatomic_xchg(ptr, x)
+
#endif /* _KERNEL_H */
diff --git a/tools/testing/radix-tree/linux/slab.h b/tools/testing/radix-tree/linux/slab.h
index 452e2bf..446639f 100644
--- a/tools/testing/radix-tree/linux/slab.h
+++ b/tools/testing/radix-tree/linux/slab.h
@@ -7,6 +7,9 @@
#define SLAB_PANIC 2
#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
+void *kmalloc(size_t size, gfp_t);
+void kfree(void *);
+
struct kmem_cache {
int size;
void (*ctor)(void *);
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:40 +0100 |
| Subject | [PATCH 08/29] tools: Add more bitmap functions |
| Message-ID | <sEh21-uC-1@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <willy@linux.intel.com>
I need the following functions for the radix tree:
bitmap_fill
find_next_zero_bit
bitmap_empty
bitmap_full
Copy the implementations from include/linux/bitmap.h and lib/find_bit.c
---
tools/include/linux/bitmap.h | 26 ++++++++++++++++++++++++++
tools/lib/find_bit.c | 8 ++++++++
2 files changed, 34 insertions(+)
diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h
index 43c1c50..eef41d5 100644
--- a/tools/include/linux/bitmap.h
+++ b/tools/include/linux/bitmap.h
@@ -35,6 +35,32 @@ static inline void bitmap_zero(unsigned long *dst, int nbits)
}
}
+static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
+{
+ unsigned int nlongs = BITS_TO_LONGS(nbits);
+ if (!small_const_nbits(nbits)) {
+ unsigned int len = (nlongs - 1) * sizeof(unsigned long);
+ memset(dst, 0xff, len);
+ }
+ dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
+}
+
+static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
+{
+ if (small_const_nbits(nbits))
+ return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
+
+ return find_first_bit(src, nbits) == nbits;
+}
+
+static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
+{
+ if (small_const_nbits(nbits))
+ return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
+
+ return find_first_zero_bit(src, nbits) == nbits;
+}
+
static inline int bitmap_weight(const unsigned long *src, int nbits)
{
if (small_const_nbits(nbits))
diff --git a/tools/lib/find_bit.c b/tools/lib/find_bit.c
index 9122a9e..de26b6f 100644
--- a/tools/lib/find_bit.c
+++ b/tools/lib/find_bit.c
@@ -66,6 +66,14 @@ unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
}
#endif
+#ifndef find_next_zero_bit
+unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
+ unsigned long offset)
+{
+ return _find_next_bit(addr, size, offset, ~0UL);
+}
+#endif
+
#ifndef find_first_bit
/*
* Find the first set bit in a memory region.
--
2.10.2
[toc] | [prev] | [next] | [standalone]
| From | Matthew Wilcox <mawilcox@linuxonhyperv.com> |
|---|---|
| Date | 2016-11-16 23:40 +0100 |
| Subject | [PATCH 21/29] radix-tree: Delete radix_tree_locate_item() |
| Message-ID | <sEh22-uC-3@gated-at.bofh.it> |
| In reply to | #1523884 |
From: Matthew Wilcox <mawilcox@microsoft.com>
This rather complicated function can be better implemented as an iterator.
It has only one caller, so move the functionality to the only place that
needs it. Update the test suite to follow the same pattern.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
include/linux/radix-tree.h | 1 -
lib/radix-tree.c | 99 -----------------------------------
mm/shmem.c | 26 ++++++++-
tools/testing/radix-tree/main.c | 8 +--
tools/testing/radix-tree/multiorder.c | 2 +-
tools/testing/radix-tree/test.c | 22 ++++++++
tools/testing/radix-tree/test.h | 2 +
7 files changed, 54 insertions(+), 106 deletions(-)
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index 36c6175..57bf635 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -306,7 +306,6 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
unsigned long nr_to_tag,
unsigned int fromtag, unsigned int totag);
int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);
-unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item);
static inline void radix_tree_preload_end(void)
{
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 27b53ef..7e70ac9 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1605,105 +1605,6 @@ radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,
}
EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot);
-#if defined(CONFIG_SHMEM) && defined(CONFIG_SWAP)
-#include <linux/sched.h> /* for cond_resched() */
-
-struct locate_info {
- unsigned long found_index;
- bool stop;
-};
-
-/*
- * This linear search is at present only useful to shmem_unuse_inode().
- */
-static unsigned long __locate(struct radix_tree_node *slot, void *item,
- unsigned long index, struct locate_info *info)
-{
- unsigned long i;
-
- do {
- unsigned int shift = slot->shift;
-
- for (i = (index >> shift) & RADIX_TREE_MAP_MASK;
- i < RADIX_TREE_MAP_SIZE;
- i++, index += (1UL << shift)) {
- struct radix_tree_node *node =
- rcu_dereference_raw(slot->slots[i]);
- if (node == RADIX_TREE_RETRY)
- goto out;
- if (!radix_tree_is_internal_node(node)) {
- if (node == item) {
- info->found_index = index;
- info->stop = true;
- goto out;
- }
- continue;
- }
- node = entry_to_node(node);
- if (is_sibling_entry(slot, node))
- continue;
- slot = node;
- break;
- }
- } while (i < RADIX_TREE_MAP_SIZE);
-
-out:
- if ((index == 0) && (i == RADIX_TREE_MAP_SIZE))
- info->stop = true;
- return index;
-}
-
-/**
- * radix_tree_locate_item - search through radix tree for item
- * @root: radix tree root
- * @item: item to be found
- *
- * Returns index where item was found, or -1 if not found.
- * Caller must hold no lock (since this time-consuming function needs
- * to be preemptible), and must check afterwards if item is still there.
- */
-unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item)
-{
- struct radix_tree_node *node;
- unsigned long max_index;
- unsigned long cur_index = 0;
- struct locate_info info = {
- .found_index = -1,
- .stop = false,
- };
-
- do {
- rcu_read_lock();
- node = rcu_dereference_raw(root->rnode);
- if (!radix_tree_is_internal_node(node)) {
- rcu_read_unlock();
- if (node == item)
- info.found_index = 0;
- break;
- }
-
- node = entry_to_node(node);
-
- max_index = node_maxindex(node);
- if (cur_index > max_index) {
- rcu_read_unlock();
- break;
- }
-
- cur_index = __locate(node, item, cur_index, &info);
- rcu_read_unlock();
- cond_resched();
- } while (!info.stop && cur_index <= max_index);
-
- return info.found_index;
-}
-#else
-unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item)
-{
- return -1;
-}
-#endif /* CONFIG_SHMEM && CONFIG_SWAP */
-
/**
* radix_tree_shrink - shrink radix tree to minimum height
* @root radix tree root
diff --git a/mm/shmem.c b/mm/shmem.c
index 0b3fe33..8f9c9aa 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1046,6 +1046,30 @@ static void shmem_evict_inode(struct inode *inode)
clear_inode(inode);
}
+static unsigned long find_swap_entry(struct radix_tree_root *root, void *item)
+{
+ struct radix_tree_iter iter;
+ void **slot;
+ unsigned long found = -1;
+ unsigned int checked = 0;
+
+ rcu_read_lock();
+ radix_tree_for_each_slot(slot, root, &iter, 0) {
+ if (*slot == item) {
+ found = iter.index;
+ break;
+ }
+ checked++;
+ if ((checked % 4096) != 0)
+ continue;
+ slot = radix_tree_iter_next(slot, &iter);
+ cond_resched_rcu();
+ }
+
+ rcu_read_unlock();
+ return found;
+}
+
/*
* If swap found in inode, free it and move page from swapcache to filecache.
*/
@@ -1059,7 +1083,7 @@ static int shmem_unuse_inode(struct shmem_inode_info *info,
int error = 0;
radswap = swp_to_radix_entry(swap);
- index = radix_tree_locate_item(&mapping->page_tree, radswap);
+ index = find_swap_entry(&mapping->page_tree, radswap);
if (index == -1)
return -EAGAIN; /* tell shmem_unuse we found nothing */
diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c
index 8621542..93a77f9 100644
--- a/tools/testing/radix-tree/main.c
+++ b/tools/testing/radix-tree/main.c
@@ -239,7 +239,7 @@ static void __locate_check(struct radix_tree_root *tree, unsigned long index,
item_insert_order(tree, index, order);
item = item_lookup(tree, index);
- index2 = radix_tree_locate_item(tree, item);
+ index2 = find_item(tree, item);
if (index != index2) {
printf("index %ld order %d inserted; found %ld\n",
index, order, index2);
@@ -273,17 +273,17 @@ static void locate_check(void)
index += (1UL << order)) {
__locate_check(&tree, index + offset, order);
}
- if (radix_tree_locate_item(&tree, &tree) != -1)
+ if (find_item(&tree, &tree) != -1)
abort();
item_kill_tree(&tree);
}
}
- if (radix_tree_locate_item(&tree, &tree) != -1)
+ if (find_item(&tree, &tree) != -1)
abort();
__locate_check(&tree, -1, 0);
- if (radix_tree_locate_item(&tree, &tree) != -1)
+ if (find_item(&tree, &tree) != -1)
abort();
item_kill_tree(&tree);
}
diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index 588209a..400de5c 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -347,7 +347,7 @@ static void __multiorder_join(unsigned long index,
item_insert_order(&tree, index, order2);
item = radix_tree_lookup(&tree, index);
radix_tree_join(&tree, index + 1, order1, item2);
- loc = radix_tree_locate_item(&tree, item);
+ loc = find_item(&tree, item);
if (loc == -1)
free(item);
item = radix_tree_lookup(&tree, index + 1);
diff --git a/tools/testing/radix-tree/test.c b/tools/testing/radix-tree/test.c
index a6e8099..a68ed3b 100644
--- a/tools/testing/radix-tree/test.c
+++ b/tools/testing/radix-tree/test.c
@@ -142,6 +142,28 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start,
assert(nfound == 0);
}
+/* Use the same pattern as find_swap_entry() in mm/shmem.c */
+unsigned long find_item(struct radix_tree_root *root, void *item)
+{
+ struct radix_tree_iter iter;
+ void **slot;
+ unsigned long found = -1;
+ unsigned long checked = 0;
+
+ radix_tree_for_each_slot(slot, root, &iter, 0) {
+ if (*slot == item) {
+ found = iter.index;
+ break;
+ }
+ checked++;
+ if ((checked % 4) != 0)
+ continue;
+ slot = radix_tree_iter_next(slot, &iter);
+ }
+
+ return found;
+}
+
static int verify_node(struct radix_tree_node *slot, unsigned int tag,
int tagged)
{
diff --git a/tools/testing/radix-tree/test.h b/tools/testing/radix-tree/test.h
index b678f13..ccdd3c1 100644
--- a/tools/testing/radix-tree/test.h
+++ b/tools/testing/radix-tree/test.h
@@ -27,6 +27,8 @@ void item_full_scan(struct radix_tree_root *root, unsigned long start,
unsigned long nr, int chunk);
void item_kill_tree(struct radix_tree_root *root);
+unsigned long find_item(struct radix_tree_root *, void *item);
+
void tag_check(void);
void multiorder_checks(void);
void iteration_test(void);
--
2.10.2
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