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Groups > linux.kernel > #1379616 > unrolled thread
| Started by | Mel Gorman <mgorman@techsingularity.net> |
|---|---|
| First post | 2016-04-15 11:20 +0200 |
| Last post | 2016-04-15 11:40 +0200 |
| Articles | 8 — 2 participants |
Back to article view | Back to linux.kernel
[PATCH 00/27] Move LRU page reclaim from zones to nodes v5 Mel Gorman <mgorman@techsingularity.net> - 2016-04-15 11:20 +0200
[PATCH 22/27] mm: Convert zone_reclaim to node_reclaim Mel Gorman <mgorman@techsingularity.net> - 2016-04-15 11:20 +0200
[PATCH 23/27] mm, vmscan: Add classzone information to tracepoints Mel Gorman <mgorman@techsingularity.net> - 2016-04-15 11:20 +0200
[PATCH 06/27] mm, vmscan: Make kswapd reclaim in terms of nodes Mel Gorman <mgorman@techsingularity.net> - 2016-04-15 11:20 +0200
Re: [PATCH 06/27] mm, vmscan: Make kswapd reclaim in terms of nodes Vlastimil Babka <vbabka@suse.cz> - 2016-04-28 10:40 +0200
[PATCH 08/27] mm, vmscan: Simplify the logic deciding whether kswapd sleeps Mel Gorman <mgorman@techsingularity.net> - 2016-04-15 11:20 +0200
[PATCH 14/27] mm, workingset: Make working set detection node-aware Mel Gorman <mgorman@techsingularity.net> - 2016-04-15 11:20 +0200
[PATCH 01/27] mm, vmstat: Add infrastructure for per-node vmstats Mel Gorman <mgorman@techsingularity.net> - 2016-04-15 11:40 +0200
| From | Mel Gorman <mgorman@techsingularity.net> |
|---|---|
| Date | 2016-04-15 11:20 +0200 |
| Subject | [PATCH 00/27] Move LRU page reclaim from zones to nodes v5 |
| Message-ID | <ro84W-In-3@gated-at.bofh.it> |
Changelog since v4
o Rebase on top of v3 of page allocator optimisation series
Changelog since v3
o Rebase on top of the page allocator optimisation series
o Remove RFC tag
This is the latest version of a series that moves LRUs from the zones to
the node that is based upon 4.6-rc3 plus the page allocator optimisation
series. Conceptually, this is simple but there are a lot of details. Some
of the broad motivations for this are;
1. The residency of a page partially depends on what zone the page was
allocated from. This is partially combatted by the fair zone allocation
policy but that is a partial solution that introduces overhead in the
page allocator paths.
2. Currently, reclaim on node 0 behaves slightly different to node 1. For
example, direct reclaim scans in zonelist order and reclaims even if
the zone is over the high watermark regardless of the age of pages
in that LRU. Kswapd on the other hand starts reclaim on the highest
unbalanced zone. A difference in distribution of file/anon pages due
to when they were allocated results can result in a difference in
again. While the fair zone allocation policy mitigates some of the
problems here, the page reclaim results on a multi-zone node will
always be different to a single-zone node.
it was scheduled on as a result.
3. kswapd and the page allocator scan zones in the opposite order to
avoid interfering with each other but it's sensitive to timing. This
mitigates the page allocator using pages that were allocated very recently
in the ideal case but it's sensitive to timing. When kswapd is allocating
from lower zones then it's great but during the rebalancing of the highest
zone, the page allocator and kswapd interfere with each other. It's worse
if the highest zone is small and difficult to balance.
4. slab shrinkers are node-based which makes it harder to identify the exact
relationship between slab reclaim and LRU reclaim.
The reason we have zone-based reclaim is that we used to have
large highmem zones in common configurations and it was necessary
to quickly find ZONE_NORMAL pages for reclaim. Today, this is much
less of a concern as machines with lots of memory will (or should) use
64-bit kernels. Combinations of 32-bit hardware and 64-bit hardware are
rare. Machines that do use highmem should have relatively low highmem:lowmem
ratios than we worried about in the past.
Conceptually, moving to node LRUs should be easier to understand. The
page allocator plays fewer tricks to game reclaim and reclaim behaves
similarly on all nodes.
It was tested on a UMA (16 cores single socket) and a NUMA machine (48
cores, 2 sockets). In most cases, only the UMA results are presented as
the NUMA machine takes an excessive amount of time to complete tests.
There may be an obvious difference in the number of
allocations from each zone as the fair zone allocation policy is removed
towards the end of the series. In cases where the working set exceeds memory,
the differences will be small but on small workloads it'll be very obvious.
For example, these are the allocation stats on a workload that is doing small
amounts of dd.
4.6.0-rc1 4.6.0-rc1
vanilla nodelru-v3
DMA allocs 0 0
DMA32 allocs 1961196 0
Normal allocs 3355799 5247180
Movable allocs 0 0
The key reason why this is not a problem is that kswapd will sleep if any
applicable zone for a classzone is free. If it tried to balance all zones
then there would be excessive reclaim.
bonnie
------
This was configured to do an IO test with a working set 2*RAM using the
ext4 filesystem. For both machines, there was no significant performance
difference between them but this is the result for the UMA machine
bonnie
4.6.0-rc1 4.6.0-rc1
vanilla nodelru-v3r10
Hmean SeqOut Char 53306.32 ( 0.00%) 79027.86 ( 48.25%)
Hmean SeqOut Block 87796.15 ( 0.00%) 87881.69 ( 0.10%)
Hmean SeqOut Rewrite 35996.31 ( 0.00%) 36355.59 ( 1.00%)
Hmean SeqIn Char 38789.17 ( 0.00%) 76356.20 ( 96.85%)
Hmean SeqIn Block 105315.39 ( 0.00%) 105514.07 ( 0.19%)
Hmean Random seeks 329.80 ( 0.00%) 334.36 ( 1.38%)
Hmean SeqCreate ops 4.62 ( 0.00%) 4.62 ( 0.00%)
Hmean SeqCreate read 4.62 ( 0.00%) 4.62 ( 0.00%)
Hmean SeqCreate del 599.29 ( 0.00%) 1580.23 (163.68%)
Hmean RandCreate ops 5.00 ( 0.00%) 5.00 ( 0.00%)
Hmean RandCreate read 5.00 ( 0.00%) 4.62 ( -7.69%)
Hmean RandCreate del 629.51 ( 0.00%) 1634.55 (159.66%)
4.6.0-rc1 4.6.0-rc1
vanillanodelru-v3r10
User 2049.02 1078.82
System 294.25 181.00
Elapsed 6960.58 6021.58
Note that the massive gains shown here are possible an anomaly. It has been noted
that in some cases, bonnie gets an artifical boost due to dumb reclaim luck. There
is no guarantee this result would be reproducible on the same machine let alone
any other machine. That said, the VM stats are interesting;
However, the overall VM stats are interesting
4.5.0-rc3 4.5.0-rc3
mmotm-20160209 nodelru-v2
Swap Ins 14 0
Swap Outs 873 0
DMA allocs 0 0
DMA32 allocs 38259888 36320496
Normal allocs 64762073 66488556
Movable allocs 0 0
Allocation stalls 3584 0
Direct pages scanned 736769 0
Kswapd pages scanned 77818637 78836064
Kswapd pages reclaimed 77782378 78812260
Direct pages reclaimed 736548 0
Kswapd efficiency 99% 99%
Kswapd velocity 11179.907 13092.256
Direct efficiency 99% 100%
Direct velocity 105.849 0.000
The series does not swap the workload and it never stalls on direct reclaim. There
is a slight increase in kswapd scans but it's offset by the elimination of direct
scans and the overall scanning velocity is not noticably higher. While it's not
reported here, the overall IO stats and CPU usage over time are very similar. kswapd
CPU usage is slightly elevated but (0.5% usage to roughly 1.2% usage over time) but
that is acceptable given the lack of direct reclaim.
tiobench
--------
tiobench is a flawed benchmark but it's very important in this case. tiobench
benefited from a bug prior to the fair zone allocation policy that allowed
old pages to be artificially preserved. The visible impact was that performance
exceeded the physical capabilities of the disk. With this patch applied the results are
tiobench Throughput
tiobench Throughput
4.6.0-rc1 4.6.0-rc1
vanilla nodelru-v3
Hmean PotentialReadSpeed 85.84 ( 0.00%) 86.20 ( 0.42%)
Hmean SeqRead-MB/sec-1 84.48 ( 0.00%) 84.60 ( 0.14%)
Hmean SeqRead-MB/sec-2 75.69 ( 0.00%) 75.44 ( -0.34%)
Hmean SeqRead-MB/sec-4 77.35 ( 0.00%) 77.62 ( 0.35%)
Hmean SeqRead-MB/sec-8 68.29 ( 0.00%) 68.58 ( 0.43%)
Hmean SeqRead-MB/sec-16 62.82 ( 0.00%) 62.72 ( -0.15%)
Hmean RandRead-MB/sec-1 0.93 ( 0.00%) 0.88 ( -4.69%)
Hmean RandRead-MB/sec-2 1.11 ( 0.00%) 1.08 ( -3.20%)
Hmean RandRead-MB/sec-4 1.52 ( 0.00%) 1.48 ( -2.86%)
Hmean RandRead-MB/sec-8 1.70 ( 0.00%) 1.70 ( -0.26%)
Hmean RandRead-MB/sec-16 1.96 ( 0.00%) 1.91 ( -2.49%)
Hmean SeqWrite-MB/sec-1 83.01 ( 0.00%) 83.07 ( 0.07%)
Hmean SeqWrite-MB/sec-2 77.80 ( 0.00%) 78.20 ( 0.52%)
Hmean SeqWrite-MB/sec-4 81.68 ( 0.00%) 81.72 ( 0.05%)
Hmean SeqWrite-MB/sec-8 78.17 ( 0.00%) 78.41 ( 0.31%)
Hmean SeqWrite-MB/sec-16 80.08 ( 0.00%) 80.08 ( 0.01%)
Hmean RandWrite-MB/sec-1 1.17 ( 0.00%) 1.17 ( -0.03%)
Hmean RandWrite-MB/sec-2 1.02 ( 0.00%) 1.06 ( 4.21%)
Hmean RandWrite-MB/sec-4 1.02 ( 0.00%) 1.04 ( 2.32%)
Hmean RandWrite-MB/sec-8 0.95 ( 0.00%) 0.97 ( 1.75%)
Hmean RandWrite-MB/sec-16 0.95 ( 0.00%) 0.96 ( 0.97%)
Note that the performance is almost identical allowing us to conclude that
the correct reclaim behaviour granted by the fair zone allocation policy
is preserved.
stutter
-------
stutter simulates a simple workload. One part uses a lot of anonymous
memory, a second measures mmap latency and a third copies a large file.
The primary metric is checking for mmap latency.
stutter
4.6.0-rc1 4.6.0-rc1
vanilla nodelru-v3
Min mmap 13.4442 ( 0.00%) 13.6705 ( -1.68%)
1st-qrtle mmap 38.0442 ( 0.00%) 37.7842 ( 0.68%)
2nd-qrtle mmap 78.5109 ( 0.00%) 40.3648 ( 48.59%)
3rd-qrtle mmap 86.7806 ( 0.00%) 46.2499 ( 46.70%)
Max-90% mmap 89.7028 ( 0.00%) 86.5790 ( 3.48%)
Max-93% mmap 90.6776 ( 0.00%) 89.5367 ( 1.26%)
Max-95% mmap 91.1678 ( 0.00%) 90.3138 ( 0.94%)
Max-99% mmap 92.0036 ( 0.00%) 93.2003 ( -1.30%)
Max mmap 167.0073 ( 0.00%) 94.5935 ( 43.36%)
Mean mmap 68.7672 ( 0.00%) 48.9853 ( 28.77%)
Best99%Mean mmap 68.5246 ( 0.00%) 48.5354 ( 29.17%)
Best95%Mean mmap 67.5540 ( 0.00%) 46.7102 ( 30.86%)
Best90%Mean mmap 66.2798 ( 0.00%) 44.3547 ( 33.08%)
Best50%Mean mmap 50.7730 ( 0.00%) 37.1298 ( 26.87%)
Best10%Mean mmap 35.8311 ( 0.00%) 33.6910 ( 5.97%)
Best5%Mean mmap 34.0159 ( 0.00%) 31.4259 ( 7.61%)
Best1%Mean mmap 22.1306 ( 0.00%) 24.8851 (-12.45%)
4.6.0-rc1 4.6.0-rc1
vanillanodelru-v3r10
User 1.51 0.97
System 138.03 122.58
Elapsed 2420.90 2394.80
The VM stats in this case were not that intresting and are very roughly comparable.
Page allocator intensive workloads showed few differences as the cost
of the fair zone allocation policy does not dominate from a userspace
perspective but a microbench of just the allocator shows a difference
4.6.0-rc1 4.6.0-rc1
vanilla nodelru-v3
Min total-odr0-1 725.00 ( 0.00%) 697.00 ( 3.86%)
Min total-odr0-2 559.00 ( 0.00%) 527.00 ( 5.72%)
Min total-odr0-4 459.00 ( 0.00%) 436.00 ( 5.01%)
Min total-odr0-8 403.00 ( 0.00%) 391.00 ( 2.98%)
Min total-odr0-16 329.00 ( 0.00%) 366.00 (-11.25%)
Min total-odr0-32 365.00 ( 0.00%) 355.00 ( 2.74%)
Min total-odr0-64 297.00 ( 0.00%) 348.00 (-17.17%)
Min total-odr0-128 752.00 ( 0.00%) 344.00 ( 54.26%)
Min total-odr0-256 385.00 ( 0.00%) 379.00 ( 1.56%)
Min total-odr0-512 899.00 ( 0.00%) 414.00 ( 53.95%)
Min total-odr0-1024 763.00 ( 0.00%) 530.00 ( 30.54%)
Min total-odr0-2048 982.00 ( 0.00%) 469.00 ( 52.24%)
Min total-odr0-4096 928.00 ( 0.00%) 526.00 ( 43.32%)
Min total-odr0-8192 1007.00 ( 0.00%) 768.00 ( 23.73%)
Min total-odr0-16384 375.00 ( 0.00%) 366.00 ( 2.40%)
This series is not without its hazards. There are at least three areas
that I'm concerned with even though I could not reproduce any problems in
that area.
1. Reclaim/compaction is going to be affected because the amount of reclaim is
no longer targetted at a specific zone. Compaction works on a per-zone basis
so there is no guarantee that reclaiming a few THP's worth page pages will
have a positive impact on compaction success rates.
2. The Slab/LRU reclaim ratio is affected because the frequency the shrinkers
are called is now different. This may or may not be a problem but if it
is, it'll be because shrinkers are not called enough and some balancing
is required.
3. The anon/file reclaim ratio may be affected. Pages about to be dirtied are
distributed between zones and the fair zone allocation policy used to do
something very similar for anon. The distribution is now different but not
necessarily in any way that matters but it's still worth bearing in mind.
Documentation/cgroup-v1/memcg_test.txt | 4 +-
Documentation/cgroup-v1/memory.txt | 4 +-
arch/s390/appldata/appldata_mem.c | 2 +-
arch/tile/mm/pgtable.c | 18 +-
drivers/base/node.c | 73 +--
drivers/staging/android/lowmemorykiller.c | 12 +-
fs/fs-writeback.c | 4 +-
fs/fuse/file.c | 8 +-
fs/nfs/internal.h | 2 +-
fs/nfs/write.c | 2 +-
fs/proc/meminfo.c | 14 +-
include/linux/backing-dev.h | 2 +-
include/linux/memcontrol.h | 30 +-
include/linux/mm_inline.h | 4 +-
include/linux/mm_types.h | 2 +-
include/linux/mmzone.h | 156 +++---
include/linux/swap.h | 13 +-
include/linux/topology.h | 2 +-
include/linux/vm_event_item.h | 14 +-
include/linux/vmstat.h | 111 +++-
include/linux/writeback.h | 2 +-
include/trace/events/vmscan.h | 40 +-
include/trace/events/writeback.h | 10 +-
kernel/power/snapshot.c | 10 +-
kernel/sysctl.c | 4 +-
mm/backing-dev.c | 14 +-
mm/compaction.c | 24 +-
mm/filemap.c | 14 +-
mm/huge_memory.c | 14 +-
mm/internal.h | 11 +-
mm/memcontrol.c | 235 ++++-----
mm/memory-failure.c | 4 +-
mm/memory_hotplug.c | 7 +-
mm/mempolicy.c | 2 +-
mm/migrate.c | 35 +-
mm/mlock.c | 12 +-
mm/page-writeback.c | 119 ++---
mm/page_alloc.c | 289 +++++-----
mm/page_idle.c | 4 +-
mm/rmap.c | 15 +-
mm/shmem.c | 12 +-
mm/swap.c | 66 +--
mm/swap_state.c | 4 +-
mm/util.c | 4 +-
mm/vmscan.c | 847 ++++++++++++++----------------
mm/vmstat.c | 369 ++++++++++---
mm/workingset.c | 53 +-
47 files changed, 1476 insertions(+), 1221 deletions(-)
--
2.6.4
[toc] | [next] | [standalone]
| From | Mel Gorman <mgorman@techsingularity.net> |
|---|---|
| Date | 2016-04-15 11:20 +0200 |
| Subject | [PATCH 22/27] mm: Convert zone_reclaim to node_reclaim |
| Message-ID | <ro84Z-In-75@gated-at.bofh.it> |
| In reply to | #1379616 |
As reclaim is now per-node based, convert zone_reclaim to be node_reclaim.
It is possible that a node will be reclaimed multiple times if it has
multiple zones but this is unavoidable without caching all nodes traversed
so far. The documentation and interface to userspace is the same from
a configuration perspective and will will be similar in behaviour unless
the node-local allocation requests were also limited to lower zones.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
include/linux/mmzone.h | 18 +++++------
include/linux/swap.h | 9 +++---
include/linux/topology.h | 2 +-
kernel/sysctl.c | 4 +--
mm/huge_memory.c | 4 +--
mm/internal.h | 8 ++---
mm/page_alloc.c | 24 ++++++++++-----
mm/vmscan.c | 77 ++++++++++++++++++++++++------------------------
8 files changed, 77 insertions(+), 69 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 8ffe0208d9c7..53dd1a6aa444 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -363,14 +363,6 @@ struct zone {
unsigned long *pageblock_flags;
#endif /* CONFIG_SPARSEMEM */
-#ifdef CONFIG_NUMA
- /*
- * zone reclaim becomes active if more unmapped pages exist.
- */
- unsigned long min_unmapped_pages;
- unsigned long min_slab_pages;
-#endif /* CONFIG_NUMA */
-
/* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
unsigned long zone_start_pfn;
@@ -515,7 +507,6 @@ struct zone {
} ____cacheline_internodealigned_in_smp;
enum zone_flags {
- ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
ZONE_FAIR_DEPLETED, /* fair zone policy batch depleted */
};
@@ -531,6 +522,7 @@ enum pgdat_flags {
PGDAT_WRITEBACK, /* reclaim scanning has recently found
* many pages under writeback
*/
+ PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */
};
static inline unsigned long zone_end_pfn(const struct zone *zone)
@@ -679,6 +671,14 @@ typedef struct pglist_data {
*/
unsigned long totalreserve_pages;
+#ifdef CONFIG_NUMA
+ /*
+ * zone reclaim becomes active if more unmapped pages exist.
+ */
+ unsigned long min_unmapped_pages;
+ unsigned long min_slab_pages;
+#endif /* CONFIG_NUMA */
+
/* Write-intensive fields used from the page allocator */
ZONE_PADDING(_pad1_)
spinlock_t lru_lock;
diff --git a/include/linux/swap.h b/include/linux/swap.h
index aa566cec54fb..1eefd583cdfb 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -333,13 +333,14 @@ extern int remove_mapping(struct address_space *mapping, struct page *page);
extern unsigned long vm_total_pages;
#ifdef CONFIG_NUMA
-extern int zone_reclaim_mode;
+extern int node_reclaim_mode;
extern int sysctl_min_unmapped_ratio;
extern int sysctl_min_slab_ratio;
-extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
+extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
#else
-#define zone_reclaim_mode 0
-static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
+#define node_reclaim_mode 0
+static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
+ unsigned int order)
{
return 0;
}
diff --git a/include/linux/topology.h b/include/linux/topology.h
index afce69296ac0..cb0775e1ee4b 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -54,7 +54,7 @@ int arch_update_cpu_topology(void);
/*
* If the distance between nodes in a system is larger than RECLAIM_DISTANCE
* (in whatever arch specific measurement units returned by node_distance())
- * and zone_reclaim_mode is enabled then the VM will only call zone_reclaim()
+ * and node_reclaim_mode is enabled then the VM will only call node_reclaim()
* on nodes within this distance.
*/
#define RECLAIM_DISTANCE 30
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 725587f10667..27148ed6bf6a 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1476,8 +1476,8 @@ static struct ctl_table vm_table[] = {
#ifdef CONFIG_NUMA
{
.procname = "zone_reclaim_mode",
- .data = &zone_reclaim_mode,
- .maxlen = sizeof(zone_reclaim_mode),
+ .data = &node_reclaim_mode,
+ .maxlen = sizeof(node_reclaim_mode),
.mode = 0644,
.proc_handler = proc_dointvec,
.extra1 = &zero,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 6d73f1a566ae..39ab35a92e53 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2197,10 +2197,10 @@ static bool khugepaged_scan_abort(int nid)
int i;
/*
- * If zone_reclaim_mode is disabled, then no extra effort is made to
+ * If node_reclaim_mode is disabled, then no extra effort is made to
* allocate memory locally.
*/
- if (!zone_reclaim_mode)
+ if (!node_reclaim_mode)
return false;
/* If there is a count for this node already, it must be acceptable */
diff --git a/mm/internal.h b/mm/internal.h
index 5f8914e7af39..ec08fdfc04fe 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -427,10 +427,10 @@ static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
}
#endif /* CONFIG_SPARSEMEM */
-#define ZONE_RECLAIM_NOSCAN -2
-#define ZONE_RECLAIM_FULL -1
-#define ZONE_RECLAIM_SOME 0
-#define ZONE_RECLAIM_SUCCESS 1
+#define NODE_RECLAIM_NOSCAN -2
+#define NODE_RECLAIM_FULL -1
+#define NODE_RECLAIM_SOME 0
+#define NODE_RECLAIM_SUCCESS 1
extern int hwpoison_filter(struct page *p);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 01b92a22b53c..fa6534bc4e98 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2983,16 +2983,16 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
if (alloc_flags & ALLOC_NO_WATERMARKS)
goto try_this_zone;
- if (zone_reclaim_mode == 0 ||
+ if (node_reclaim_mode == 0 ||
!zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
continue;
- ret = zone_reclaim(zone, gfp_mask, order);
+ ret = node_reclaim(zone->zone_pgdat, gfp_mask, order);
switch (ret) {
- case ZONE_RECLAIM_NOSCAN:
+ case NODE_RECLAIM_NOSCAN:
/* did not scan */
continue;
- case ZONE_RECLAIM_FULL:
+ case NODE_RECLAIM_FULL:
/* scanned but unreclaimable */
continue;
default:
@@ -5780,9 +5780,9 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat)
zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
#ifdef CONFIG_NUMA
zone->node = nid;
- zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
+ pgdat->min_unmapped_pages += (freesize*sysctl_min_unmapped_ratio)
/ 100;
- zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
+ pgdat->min_slab_pages += (freesize * sysctl_min_slab_ratio) / 100;
#endif
zone->name = zone_names[j];
zone->zone_pgdat = pgdat;
@@ -6807,6 +6807,7 @@ int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
+ struct pglist_data *pgdat;
struct zone *zone;
int rc;
@@ -6814,8 +6815,11 @@ int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
if (rc)
return rc;
+ for_each_online_pgdat(pgdat)
+ pgdat->min_slab_pages = 0;
+
for_each_zone(zone)
- zone->min_unmapped_pages = (zone->managed_pages *
+ zone->zone_pgdat->min_unmapped_pages += (zone->managed_pages *
sysctl_min_unmapped_ratio) / 100;
return 0;
}
@@ -6823,6 +6827,7 @@ int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
+ struct pglist_data *pgdat;
struct zone *zone;
int rc;
@@ -6830,8 +6835,11 @@ int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
if (rc)
return rc;
+ for_each_online_pgdat(pgdat)
+ pgdat->min_slab_pages = 0;
+
for_each_zone(zone)
- zone->min_slab_pages = (zone->managed_pages *
+ zone->zone_pgdat->min_slab_pages += (zone->managed_pages *
sysctl_min_slab_ratio) / 100;
return 0;
}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1931e98d2f67..dfd8bdfadfe4 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3568,12 +3568,12 @@ module_init(kswapd_init)
#ifdef CONFIG_NUMA
/*
- * Zone reclaim mode
+ * Node reclaim mode
*
- * If non-zero call zone_reclaim when the number of free pages falls below
+ * If non-zero call node_reclaim when the number of free pages falls below
* the watermarks.
*/
-int zone_reclaim_mode __read_mostly;
+int node_reclaim_mode __read_mostly;
#define RECLAIM_OFF 0
#define RECLAIM_ZONE (1<<0) /* Run shrink_inactive_list on the zone */
@@ -3581,14 +3581,14 @@ int zone_reclaim_mode __read_mostly;
#define RECLAIM_UNMAP (1<<2) /* Unmap pages during reclaim */
/*
- * Priority for ZONE_RECLAIM. This determines the fraction of pages
+ * Priority for NODE_RECLAIM. This determines the fraction of pages
* of a node considered for each zone_reclaim. 4 scans 1/16th of
* a zone.
*/
-#define ZONE_RECLAIM_PRIORITY 4
+#define NODE_RECLAIM_PRIORITY 4
/*
- * Percentage of pages in a zone that must be unmapped for zone_reclaim to
+ * Percentage of pages in a zone that must be unmapped for node_reclaim to
* occur.
*/
int sysctl_min_unmapped_ratio = 1;
@@ -3614,7 +3614,7 @@ static inline unsigned long node_unmapped_file_pages(struct pglist_data *pgdat)
}
/* Work out how many page cache pages we can reclaim in this reclaim_mode */
-static unsigned long zone_pagecache_reclaimable(struct zone *zone)
+static unsigned long zone_pagecache_reclaimable(struct pglist_data *pgdat)
{
unsigned long nr_pagecache_reclaimable;
unsigned long delta = 0;
@@ -3625,14 +3625,14 @@ static unsigned long zone_pagecache_reclaimable(struct zone *zone)
* pages like swapcache and node_unmapped_file_pages() provides
* a better estimate
*/
- if (zone_reclaim_mode & RECLAIM_UNMAP)
- nr_pagecache_reclaimable = node_page_state(zone->zone_pgdat, NR_FILE_PAGES);
+ if (node_reclaim_mode & RECLAIM_UNMAP)
+ nr_pagecache_reclaimable = node_page_state(pgdat, NR_FILE_PAGES);
else
- nr_pagecache_reclaimable = node_unmapped_file_pages(zone->zone_pgdat);
+ nr_pagecache_reclaimable = node_unmapped_file_pages(pgdat);
/* If we can't clean pages, remove dirty pages from consideration */
- if (!(zone_reclaim_mode & RECLAIM_WRITE))
- delta += node_page_state(zone->zone_pgdat, NR_FILE_DIRTY);
+ if (!(node_reclaim_mode & RECLAIM_WRITE))
+ delta += node_page_state(pgdat, NR_FILE_DIRTY);
/* Watch for any possible underflows due to delta */
if (unlikely(delta > nr_pagecache_reclaimable))
@@ -3642,23 +3642,24 @@ static unsigned long zone_pagecache_reclaimable(struct zone *zone)
}
/*
- * Try to free up some pages from this zone through reclaim.
+ * Try to free up some pages from this node through reclaim.
*/
-static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
+static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned int order)
{
/* Minimum pages needed in order to stay on node */
const unsigned long nr_pages = 1 << order;
struct task_struct *p = current;
struct reclaim_state reclaim_state;
+ int classzone_idx = gfp_zone(gfp_mask);
struct scan_control sc = {
.nr_to_reclaim = max(nr_pages, SWAP_CLUSTER_MAX),
.gfp_mask = (gfp_mask = memalloc_noio_flags(gfp_mask)),
.order = order,
- .priority = ZONE_RECLAIM_PRIORITY,
- .may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE),
- .may_unmap = !!(zone_reclaim_mode & RECLAIM_UNMAP),
+ .priority = NODE_RECLAIM_PRIORITY,
+ .may_writepage = !!(node_reclaim_mode & RECLAIM_WRITE),
+ .may_unmap = !!(node_reclaim_mode & RECLAIM_UNMAP),
.may_swap = 1,
- .reclaim_idx = zone_idx(zone),
+ .reclaim_idx = classzone_idx,
};
cond_resched();
@@ -3672,13 +3673,13 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
reclaim_state.reclaimed_slab = 0;
p->reclaim_state = &reclaim_state;
- if (zone_pagecache_reclaimable(zone) > zone->min_unmapped_pages) {
+ if (zone_pagecache_reclaimable(pgdat) > pgdat->min_unmapped_pages) {
/*
* Free memory by calling shrink zone with increasing
* priorities until we have enough memory freed.
*/
do {
- shrink_node(zone->zone_pgdat, &sc, zone_idx(zone));
+ shrink_node(pgdat, &sc, classzone_idx);
} while (sc.nr_reclaimed < nr_pages && --sc.priority >= 0);
}
@@ -3688,49 +3689,47 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
return sc.nr_reclaimed >= nr_pages;
}
-int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
+int node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned int order)
{
- int node_id;
int ret;
/*
- * Zone reclaim reclaims unmapped file backed pages and
+ * Node reclaim reclaims unmapped file backed pages and
* slab pages if we are over the defined limits.
*
* A small portion of unmapped file backed pages is needed for
* file I/O otherwise pages read by file I/O will be immediately
- * thrown out if the zone is overallocated. So we do not reclaim
- * if less than a specified percentage of the zone is used by
+ * thrown out if the node is overallocated. So we do not reclaim
+ * if less than a specified percentage of the node is used by
* unmapped file backed pages.
*/
- if (zone_pagecache_reclaimable(zone) <= zone->min_unmapped_pages &&
- zone_page_state(zone, NR_SLAB_RECLAIMABLE) <= zone->min_slab_pages)
- return ZONE_RECLAIM_FULL;
+ if (zone_pagecache_reclaimable(pgdat) <= pgdat->min_unmapped_pages &&
+ sum_zone_node_page_state(pgdat->node_id, NR_SLAB_RECLAIMABLE) <= pgdat->min_slab_pages)
+ return NODE_RECLAIM_FULL;
- if (!pgdat_reclaimable(zone->zone_pgdat))
- return ZONE_RECLAIM_FULL;
+ if (!pgdat_reclaimable(pgdat))
+ return NODE_RECLAIM_FULL;
/*
* Do not scan if the allocation should not be delayed.
*/
if (!gfpflags_allow_blocking(gfp_mask) || (current->flags & PF_MEMALLOC))
- return ZONE_RECLAIM_NOSCAN;
+ return NODE_RECLAIM_NOSCAN;
/*
- * Only run zone reclaim on the local zone or on zones that do not
+ * Only run node reclaim on the local node or on nodes that do not
* have associated processors. This will favor the local processor
* over remote processors and spread off node memory allocations
* as wide as possible.
*/
- node_id = zone_to_nid(zone);
- if (node_state(node_id, N_CPU) && node_id != numa_node_id())
- return ZONE_RECLAIM_NOSCAN;
+ if (node_state(pgdat->node_id, N_CPU) && pgdat->node_id != numa_node_id())
+ return NODE_RECLAIM_NOSCAN;
- if (test_and_set_bit(ZONE_RECLAIM_LOCKED, &zone->flags))
- return ZONE_RECLAIM_NOSCAN;
+ if (test_and_set_bit(PGDAT_RECLAIM_LOCKED, &pgdat->flags))
+ return NODE_RECLAIM_NOSCAN;
- ret = __zone_reclaim(zone, gfp_mask, order);
- clear_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
+ ret = __node_reclaim(pgdat, gfp_mask, order);
+ clear_bit(PGDAT_RECLAIM_LOCKED, &pgdat->flags);
if (!ret)
count_vm_event(PGSCAN_ZONE_RECLAIM_FAILED);
--
2.6.4
[toc] | [prev] | [next] | [standalone]
| From | Mel Gorman <mgorman@techsingularity.net> |
|---|---|
| Date | 2016-04-15 11:20 +0200 |
| Subject | [PATCH 23/27] mm, vmscan: Add classzone information to tracepoints |
| Message-ID | <ro84Z-In-81@gated-at.bofh.it> |
| In reply to | #1379616 |
This is convenient when tracking down why the skip count is high because it'll
show what classzone kswapd woke up at and what zones are being isolated.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
include/trace/events/vmscan.h | 28 ++++++++++++++++++----------
mm/vmscan.c | 4 ++--
2 files changed, 20 insertions(+), 12 deletions(-)
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 897f1aa1ee5f..3d242fb8910a 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -55,21 +55,23 @@ TRACE_EVENT(mm_vmscan_kswapd_sleep,
TRACE_EVENT(mm_vmscan_kswapd_wake,
- TP_PROTO(int nid, int order),
+ TP_PROTO(int nid, int zid, int order),
- TP_ARGS(nid, order),
+ TP_ARGS(nid, zid, order),
TP_STRUCT__entry(
__field( int, nid )
+ __field( int, zid )
__field( int, order )
),
TP_fast_assign(
__entry->nid = nid;
+ __entry->zid = zid;
__entry->order = order;
),
- TP_printk("nid=%d order=%d", __entry->nid, __entry->order)
+ TP_printk("nid=%d zid=%d order=%d", __entry->nid, __entry->zid, __entry->order)
);
TRACE_EVENT(mm_vmscan_wakeup_kswapd,
@@ -266,16 +268,18 @@ TRACE_EVENT(mm_shrink_slab_end,
DECLARE_EVENT_CLASS(mm_vmscan_lru_isolate_template,
- TP_PROTO(int order,
+ TP_PROTO(int classzone_idx,
+ int order,
unsigned long nr_requested,
unsigned long nr_scanned,
unsigned long nr_taken,
isolate_mode_t isolate_mode,
int file),
- TP_ARGS(order, nr_requested, nr_scanned, nr_taken, isolate_mode, file),
+ TP_ARGS(classzone_idx, order, nr_requested, nr_scanned, nr_taken, isolate_mode, file),
TP_STRUCT__entry(
+ __field(int, classzone_idx)
__field(int, order)
__field(unsigned long, nr_requested)
__field(unsigned long, nr_scanned)
@@ -285,6 +289,7 @@ DECLARE_EVENT_CLASS(mm_vmscan_lru_isolate_template,
),
TP_fast_assign(
+ __entry->classzone_idx = classzone_idx;
__entry->order = order;
__entry->nr_requested = nr_requested;
__entry->nr_scanned = nr_scanned;
@@ -293,8 +298,9 @@ DECLARE_EVENT_CLASS(mm_vmscan_lru_isolate_template,
__entry->file = file;
),
- TP_printk("isolate_mode=%d order=%d nr_requested=%lu nr_scanned=%lu nr_taken=%lu file=%d",
+ TP_printk("isolate_mode=%d classzone=%d order=%d nr_requested=%lu nr_scanned=%lu nr_taken=%lu file=%d",
__entry->isolate_mode,
+ __entry->classzone_idx,
__entry->order,
__entry->nr_requested,
__entry->nr_scanned,
@@ -304,27 +310,29 @@ DECLARE_EVENT_CLASS(mm_vmscan_lru_isolate_template,
DEFINE_EVENT(mm_vmscan_lru_isolate_template, mm_vmscan_lru_isolate,
- TP_PROTO(int order,
+ TP_PROTO(int classzone_idx,
+ int order,
unsigned long nr_requested,
unsigned long nr_scanned,
unsigned long nr_taken,
isolate_mode_t isolate_mode,
int file),
- TP_ARGS(order, nr_requested, nr_scanned, nr_taken, isolate_mode, file)
+ TP_ARGS(classzone_idx, order, nr_requested, nr_scanned, nr_taken, isolate_mode, file)
);
DEFINE_EVENT(mm_vmscan_lru_isolate_template, mm_vmscan_memcg_isolate,
- TP_PROTO(int order,
+ TP_PROTO(int classzone_idx,
+ int order,
unsigned long nr_requested,
unsigned long nr_scanned,
unsigned long nr_taken,
isolate_mode_t isolate_mode,
int file),
- TP_ARGS(order, nr_requested, nr_scanned, nr_taken, isolate_mode, file)
+ TP_ARGS(classzone_idx, order, nr_requested, nr_scanned, nr_taken, isolate_mode, file)
);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index dfd8bdfadfe4..e5aa605da6c4 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1417,7 +1417,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
if (!list_empty(&pages_skipped))
list_splice(&pages_skipped, src);
*nr_scanned = scan;
- trace_mm_vmscan_lru_isolate(sc->order, nr_to_scan, scan,
+ trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan, scan,
nr_taken, mode, is_file_lru(lru));
return nr_taken;
}
@@ -3402,7 +3402,7 @@ static int kswapd(void *p)
* Try reclaim the requested order but if that fails
* then try sleeping on the basis of the order reclaimed.
*/
- trace_mm_vmscan_kswapd_wake(pgdat->node_id, order);
+ trace_mm_vmscan_kswapd_wake(pgdat->node_id, classzone_idx, order);
if (balance_pgdat(pgdat, order, classzone_idx) < order)
goto kswapd_try_sleep;
--
2.6.4
[toc] | [prev] | [next] | [standalone]
| From | Mel Gorman <mgorman@techsingularity.net> |
|---|---|
| Date | 2016-04-15 11:20 +0200 |
| Subject | [PATCH 06/27] mm, vmscan: Make kswapd reclaim in terms of nodes |
| Message-ID | <ro850-In-87@gated-at.bofh.it> |
| In reply to | #1379616 |
Patch "mm: vmscan: Begin reclaiming pages on a per-node basis" started
thinking of reclaim in terms of nodes but kswapd is still zone-centric. This
patch gets rid of many of the node-based versus zone-based decisions.
o A node is considered balanced when any eligible lower zone is balanced.
This eliminates one class of age-inversion problem because we avoid
reclaiming a newer page just because it's in the wrong zone
o pgdat_balanced disappears because we now only care about one zone being
balanced.
o Some anomalies related to writeback and congestion tracking being based on
zones disappear.
o kswapd no longer has to take care to reclaim zones in the reverse order
that the page allocator uses.
o Most importantly of all, reclaim from node 0 with multiple zones will
have similar aging and reclaiming characteristics as every
other node.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
mm/vmscan.c | 292 +++++++++++++++++++++---------------------------------------
1 file changed, 101 insertions(+), 191 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index f2534e8f8527..c23d8f9722ad 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2979,7 +2979,8 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
}
#endif
-static void age_active_anon(struct zone *zone, struct scan_control *sc)
+static void age_active_anon(struct pglist_data *pgdat,
+ struct zone *zone, struct scan_control *sc)
{
struct mem_cgroup *memcg;
@@ -2998,85 +2999,15 @@ static void age_active_anon(struct zone *zone, struct scan_control *sc)
} while (memcg);
}
-static bool zone_balanced(struct zone *zone, int order, bool highorder,
+static bool zone_balanced(struct zone *zone, int order,
unsigned long balance_gap, int classzone_idx)
{
unsigned long mark = high_wmark_pages(zone) + balance_gap;
- /*
- * When checking from pgdat_balanced(), kswapd should stop and sleep
- * when it reaches the high order-0 watermark and let kcompactd take
- * over. Other callers such as wakeup_kswapd() want to determine the
- * true high-order watermark.
- */
- if (IS_ENABLED(CONFIG_COMPACTION) && !highorder) {
- mark += (1UL << order);
- order = 0;
- }
-
return zone_watermark_ok_safe(zone, order, mark, classzone_idx);
}
/*
- * pgdat_balanced() is used when checking if a node is balanced.
- *
- * For order-0, all zones must be balanced!
- *
- * For high-order allocations only zones that meet watermarks and are in a
- * zone allowed by the callers classzone_idx are added to balanced_pages. The
- * total of balanced pages must be at least 25% of the zones allowed by
- * classzone_idx for the node to be considered balanced. Forcing all zones to
- * be balanced for high orders can cause excessive reclaim when there are
- * imbalanced zones.
- * The choice of 25% is due to
- * o a 16M DMA zone that is balanced will not balance a zone on any
- * reasonable sized machine
- * o On all other machines, the top zone must be at least a reasonable
- * percentage of the middle zones. For example, on 32-bit x86, highmem
- * would need to be at least 256M for it to be balance a whole node.
- * Similarly, on x86-64 the Normal zone would need to be at least 1G
- * to balance a node on its own. These seemed like reasonable ratios.
- */
-static bool pgdat_balanced(pg_data_t *pgdat, int order, int classzone_idx)
-{
- unsigned long managed_pages = 0;
- unsigned long balanced_pages = 0;
- int i;
-
- /* Check the watermark levels */
- for (i = 0; i <= classzone_idx; i++) {
- struct zone *zone = pgdat->node_zones + i;
-
- if (!populated_zone(zone))
- continue;
-
- managed_pages += zone->managed_pages;
-
- /*
- * A special case here:
- *
- * balance_pgdat() skips over all_unreclaimable after
- * DEF_PRIORITY. Effectively, it considers them balanced so
- * they must be considered balanced here as well!
- */
- if (!pgdat_reclaimable(zone->zone_pgdat)) {
- balanced_pages += zone->managed_pages;
- continue;
- }
-
- if (zone_balanced(zone, order, false, 0, i))
- balanced_pages += zone->managed_pages;
- else if (!order)
- return false;
- }
-
- if (order)
- return balanced_pages >= (managed_pages >> 2);
- else
- return true;
-}
-
-/*
* Prepare kswapd for sleeping. This verifies that there are no processes
* waiting in throttle_direct_reclaim() and that watermarks have been met.
*
@@ -3085,6 +3016,8 @@ static bool pgdat_balanced(pg_data_t *pgdat, int order, int classzone_idx)
static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
int classzone_idx)
{
+ int i;
+
/* If a direct reclaimer woke kswapd within HZ/10, it's premature */
if (remaining)
return false;
@@ -3105,101 +3038,90 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
if (waitqueue_active(&pgdat->pfmemalloc_wait))
wake_up_all(&pgdat->pfmemalloc_wait);
- return pgdat_balanced(pgdat, order, classzone_idx);
+ for (i = 0; i <= classzone_idx; i++) {
+ struct zone *zone = pgdat->node_zones + i;
+
+ if (!populated_zone(zone))
+ continue;
+
+ if (zone_balanced(zone, order, 0, classzone_idx))
+ return true;
+ }
+
+ return false;
}
/*
- * kswapd shrinks the zone by the number of pages required to reach
- * the high watermark.
+ * kswapd shrinks a node of pages that are at or below the highest usable
+ * zone that is currently unbalanced.
*
* Returns true if kswapd scanned at least the requested number of pages to
* reclaim or if the lack of progress was due to pages under writeback.
* This is used to determine if the scanning priority needs to be raised.
*/
-static bool kswapd_shrink_zone(struct zone *zone,
+static bool kswapd_shrink_node(pg_data_t *pgdat,
int classzone_idx,
struct scan_control *sc)
{
- unsigned long balance_gap;
- bool lowmem_pressure;
- struct pglist_data *pgdat = zone->zone_pgdat;
+ struct zone *zone;
+ unsigned long nr_to_reclaim = 0;
+ int z;
- /* Reclaim above the high watermark. */
- sc->nr_to_reclaim = max(SWAP_CLUSTER_MAX, high_wmark_pages(zone));
+ /* Reclaim a number of pages proportional to the number of zones */
+ for (z = 0; z <= classzone_idx; z++) {
+ zone = pgdat->node_zones + z;
+ if (!populated_zone(zone))
+ continue;
- /*
- * We put equal pressure on every zone, unless one zone has way too
- * many pages free already. The "too many pages" is defined as the
- * high wmark plus a "gap" where the gap is either the low
- * watermark or 1% of the zone, whichever is smaller.
- */
- balance_gap = min(low_wmark_pages(zone), DIV_ROUND_UP(
- zone->managed_pages, KSWAPD_ZONE_BALANCE_GAP_RATIO));
+ nr_to_reclaim += max(high_wmark_pages(zone), SWAP_CLUSTER_MAX);
+ }
/*
- * If there is no low memory pressure or the zone is balanced then no
- * reclaim is necessary
+ * Historically care was taken to put equal pressure on all zones but
+ * now pressure is applied based on node LRU order.
*/
- lowmem_pressure = (buffer_heads_over_limit && is_highmem(zone));
- if (!lowmem_pressure && zone_balanced(zone, sc->order, false,
- balance_gap, classzone_idx))
- return true;
-
- shrink_node(zone->zone_pgdat, sc, classzone_idx);
-
- /* TODO: ANOMALY */
- clear_bit(PGDAT_WRITEBACK, &pgdat->flags);
+ shrink_node(pgdat, sc, classzone_idx);
/*
- * If a zone reaches its high watermark, consider it to be no longer
- * congested. It's possible there are dirty pages backed by congested
- * BDIs but as pressure is relieved, speculatively avoid congestion
- * waits.
+ * Fragmentation may mean that the system cannot be rebalanced for
+ * high-order allocations. If twice the allocation size has been
+ * reclaimed then recheck watermarks only at order-0 to prevent
+ * excessive reclaim. Assume that a process requested a high-order
+ * can direct reclaim/compact.
*/
- if (pgdat_reclaimable(zone->zone_pgdat) &&
- zone_balanced(zone, sc->order, false, 0, classzone_idx)) {
- clear_bit(PGDAT_CONGESTED, &pgdat->flags);
- clear_bit(PGDAT_DIRTY, &pgdat->flags);
- }
+ if (sc->order && sc->nr_reclaimed >= 2UL << sc->order)
+ sc->order = 0;
return sc->nr_scanned >= sc->nr_to_reclaim;
}
/*
- * For kswapd, balance_pgdat() will work across all this node's zones until
- * they are all at high_wmark_pages(zone).
- *
- * Returns the highest zone idx kswapd was reclaiming at
+ * For kswapd, balance_pgdat() will reclaim pages across a node from zones
+ * that are eligible for use by the caller until at least one zone is
+ * balanced.
*
- * There is special handling here for zones which are full of pinned pages.
- * This can happen if the pages are all mlocked, or if they are all used by
- * device drivers (say, ZONE_DMA). Or if they are all in use by hugetlb.
- * What we do is to detect the case where all pages in the zone have been
- * scanned twice and there has been zero successful reclaim. Mark the zone as
- * dead and from now on, only perform a short scan. Basically we're polling
- * the zone for when the problem goes away.
+ * Returns the order kswapd finished reclaiming at.
*
* kswapd scans the zones in the highmem->normal->dma direction. It skips
* zones which have free_pages > high_wmark_pages(zone), but once a zone is
- * found to have free_pages <= high_wmark_pages(zone), we scan that zone and the
- * lower zones regardless of the number of free pages in the lower zones. This
- * interoperates with the page allocator fallback scheme to ensure that aging
- * of pages is balanced across the zones.
+ * found to have free_pages <= high_wmark_pages(zone), any page is that zone
+ * or lower is eligible for reclaim until at least one usable zone is
+ * balanced.
*/
static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
{
int i;
- int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */
unsigned long nr_soft_reclaimed;
unsigned long nr_soft_scanned;
+ struct zone *zone;
struct scan_control sc = {
.gfp_mask = GFP_KERNEL,
- .reclaim_idx = MAX_NR_ZONES - 1,
.order = order,
.priority = DEF_PRIORITY,
.may_writepage = !laptop_mode,
.may_unmap = 1,
.may_swap = 1,
+ .reclaim_idx = classzone_idx,
};
count_vm_event(PAGEOUTRUN);
@@ -3210,21 +3132,10 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
/* Scan from the highest requested zone to dma */
for (i = classzone_idx; i >= 0; i--) {
- struct zone *zone = pgdat->node_zones + i;
-
+ zone = pgdat->node_zones + i;
if (!populated_zone(zone))
continue;
- if (sc.priority != DEF_PRIORITY &&
- !pgdat_reclaimable(zone->zone_pgdat))
- continue;
-
- /*
- * Do some background aging of the anon list, to give
- * pages a chance to be referenced before reclaiming.
- */
- age_active_anon(zone, &sc);
-
/*
* If the number of buffer_heads in the machine
* exceeds the maximum allowed level and this node
@@ -3232,19 +3143,17 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
* it to relieve lowmem pressure.
*/
if (buffer_heads_over_limit && is_highmem_idx(i)) {
- end_zone = i;
+ classzone_idx = i;
break;
}
- if (!zone_balanced(zone, order, false, 0, 0)) {
- end_zone = i;
+ if (!zone_balanced(zone, order, 0, 0)) {
+ classzone_idx = i;
break;
} else {
/*
- * If balanced, clear the dirty and congested
- * flags
- *
- * TODO: ANOMALY
+ * If any eligible zone is balanced then the
+ * node is not considered congested or dirty.
*/
clear_bit(PGDAT_CONGESTED, &zone->zone_pgdat->flags);
clear_bit(PGDAT_DIRTY, &zone->zone_pgdat->flags);
@@ -3255,51 +3164,34 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
goto out;
/*
+ * Do some background aging of the anon list, to give
+ * pages a chance to be referenced before reclaiming. All
+ * pages are rotated regardless of classzone as this is
+ * about consistent aging.
+ */
+ age_active_anon(pgdat, &pgdat->node_zones[MAX_NR_ZONES - 1], &sc);
+
+ /*
* If we're getting trouble reclaiming, start doing writepage
* even in laptop mode.
*/
- if (sc.priority < DEF_PRIORITY - 2)
+ if (sc.priority < DEF_PRIORITY - 2 || !pgdat_reclaimable(pgdat))
sc.may_writepage = 1;
+ /* Call soft limit reclaim before calling shrink_node. */
+ sc.nr_scanned = 0;
+ nr_soft_scanned = 0;
+ nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone, sc.order,
+ sc.gfp_mask, &nr_soft_scanned);
+ sc.nr_reclaimed += nr_soft_reclaimed;
+
/*
- * Continue scanning in the highmem->dma direction stopping at
- * the last zone which needs scanning. This may reclaim lowmem
- * pages that are not necessary for zone balancing but it
- * preserves LRU ordering. It is assumed that the bulk of
- * allocation requests can use arbitrary zones with the
- * possible exception of big highmem:lowmem configurations.
+ * There should be no need to raise the scanning priority if
+ * enough pages are already being scanned that that high
+ * watermark would be met at 100% efficiency.
*/
- for (i = end_zone; i >= end_zone; i--) {
- struct zone *zone = pgdat->node_zones + i;
-
- if (!populated_zone(zone))
- continue;
-
- if (sc.priority != DEF_PRIORITY &&
- !pgdat_reclaimable(zone->zone_pgdat))
- continue;
-
- sc.nr_scanned = 0;
- sc.reclaim_idx = i;
-
- nr_soft_scanned = 0;
- /*
- * Call soft limit reclaim before calling shrink_zone.
- */
- nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone,
- order, sc.gfp_mask,
- &nr_soft_scanned);
- sc.nr_reclaimed += nr_soft_reclaimed;
-
- /*
- * There should be no need to raise the scanning
- * priority if enough pages are already being scanned
- * that that high watermark would be met at 100%
- * efficiency.
- */
- if (kswapd_shrink_zone(zone, end_zone, &sc))
- raise_priority = false;
- }
+ if (kswapd_shrink_node(pgdat, classzone_idx, &sc))
+ raise_priority = false;
/*
* If the low watermark is met there is no need for processes
@@ -3315,20 +3207,37 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
break;
/*
+ * Stop reclaiming if any eligible zone is balanced and clear
+ * node writeback or congested.
+ */
+ for (i = 0; i <= classzone_idx; i++) {
+ zone = pgdat->node_zones + i;
+ if (!populated_zone(zone))
+ continue;
+
+ if (zone_balanced(zone, sc.order, 0, classzone_idx)) {
+ clear_bit(PGDAT_CONGESTED, &pgdat->flags);
+ clear_bit(PGDAT_DIRTY, &pgdat->flags);
+ goto out;
+ }
+ }
+
+ /*
* Raise priority if scanning rate is too low or there was no
* progress in reclaiming pages
*/
if (raise_priority || !sc.nr_reclaimed)
sc.priority--;
- } while (sc.priority >= 1 &&
- !pgdat_balanced(pgdat, order, classzone_idx));
+ } while (sc.priority >= 1);
out:
/*
- * Return the highest zone idx we were reclaiming at so
- * prepare_kswapd_sleep() makes the same decisions as here.
+ * Return the order kswapd stopped reclaiming at as
+ * prepare_kswapd_sleep() takes it into account. If another caller
+ * entered the allocator slow path while kswapd was awake, order will
+ * remain at the higher level.
*/
- return end_zone;
+ return sc.order;
}
static void kswapd_try_to_sleep(pg_data_t *pgdat, int order,
@@ -3485,8 +3394,9 @@ static int kswapd(void *p)
*/
if (!ret) {
trace_mm_vmscan_kswapd_wake(pgdat->node_id, order);
- balanced_classzone_idx = balance_pgdat(pgdat, order,
- classzone_idx);
+
+ /* return value ignored until next patch */
+ balance_pgdat(pgdat, order, classzone_idx);
}
}
@@ -3516,7 +3426,7 @@ void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx)
}
if (!waitqueue_active(&pgdat->kswapd_wait))
return;
- if (zone_balanced(zone, order, true, 0, 0))
+ if (zone_balanced(zone, order, 0, 0))
return;
trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, zone_idx(zone), order);
--
2.6.4
[toc] | [prev] | [next] | [standalone]
| From | Vlastimil Babka <vbabka@suse.cz> |
|---|---|
| Date | 2016-04-28 10:40 +0200 |
| Subject | Re: [PATCH 06/27] mm, vmscan: Make kswapd reclaim in terms of nodes |
| Message-ID | <rsPEm-9y-9@gated-at.bofh.it> |
| In reply to | #1379622 |
On 04/15/2016 11:13 AM, Mel Gorman wrote:
> /*
> - * If a zone reaches its high watermark, consider it to be no longer
> - * congested. It's possible there are dirty pages backed by congested
> - * BDIs but as pressure is relieved, speculatively avoid congestion
> - * waits.
> + * Fragmentation may mean that the system cannot be rebalanced for
> + * high-order allocations. If twice the allocation size has been
> + * reclaimed then recheck watermarks only at order-0 to prevent
> + * excessive reclaim. Assume that a process requested a high-order
> + * can direct reclaim/compact.
Also kcompactd is woken up in this case...
> */
> - if (pgdat_reclaimable(zone->zone_pgdat) &&
> - zone_balanced(zone, sc->order, false, 0, classzone_idx)) {
> - clear_bit(PGDAT_CONGESTED, &pgdat->flags);
> - clear_bit(PGDAT_DIRTY, &pgdat->flags);
> - }
> + if (sc->order && sc->nr_reclaimed >= 2UL << sc->order)
> + sc->order = 0;
>
> return sc->nr_scanned >= sc->nr_to_reclaim;
This looks indeed simpler than my earlier zone_balanced() modification
you removed. However I think there's still potential of overreclaim due
to a stream of kswapd_wakeups where each will have to reclaim 2UL <<
sc->order pages, regardless of watermarks. Could be some high-order
wakeups from GFP_ATOMIC context that have order-0 fallbacks but will
cause kswapd to keep reclaiming when kcompactd can't keep up due to
fragmentation...
[toc] | [prev] | [next] | [standalone]
| From | Mel Gorman <mgorman@techsingularity.net> |
|---|---|
| Date | 2016-04-15 11:20 +0200 |
| Subject | [PATCH 08/27] mm, vmscan: Simplify the logic deciding whether kswapd sleeps |
| Message-ID | <ro850-In-89@gated-at.bofh.it> |
| In reply to | #1379616 |
kswapd goes through some complex steps trying to figure out if it
should stay awake based on the classzone_idx and the requested order.
It is unnecessarily complex and passes in an invalid classzone_idx to
balance_pgdat(). What matters most of all is whether a larger order has
been requsted and whether kswapd successfully reclaimed at the previous
order. This patch irons out the logic to check just that and the end result
is less headache inducing.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/mmzone.h | 5 ++--
mm/memory_hotplug.c | 5 ++--
mm/page_alloc.c | 2 +-
mm/vmscan.c | 79 +++++++++++++++++++++++++-------------------------
4 files changed, 46 insertions(+), 45 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 9f038d86b75b..3ec0ee859d48 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -660,8 +660,9 @@ typedef struct pglist_data {
wait_queue_head_t pfmemalloc_wait;
struct task_struct *kswapd; /* Protected by
mem_hotplug_begin/end() */
- int kswapd_max_order;
- enum zone_type classzone_idx;
+ int kswapd_order;
+ enum zone_type kswapd_classzone_idx;
+
#ifdef CONFIG_COMPACTION
int kcompactd_max_order;
enum zone_type kcompactd_classzone_idx;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 372f1099fc8f..f66a54608529 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1148,9 +1148,10 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
arch_refresh_nodedata(nid, pgdat);
} else {
- /* Reset the nr_zones and classzone_idx to 0 before reuse */
+ /* Reset the nr_zones, order and classzone_idx before reuse */
pgdat->nr_zones = 0;
- pgdat->classzone_idx = 0;
+ pgdat->kswapd_order = 0;
+ pgdat->kswapd_classzone_idx = -1;
}
/* we can use NODE_DATA(nid) from here */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8d4e46464ffb..e5a1597ee244 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5866,7 +5866,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
unsigned long end_pfn = 0;
/* pg_data_t should be reset to zero when it's allocated */
- WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
+ WARN_ON(pgdat->nr_zones || pgdat->kswapd_classzone_idx);
reset_deferred_meminit(pgdat);
pgdat->node_id = nid;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6aa05cf28a0b..ef1cfa835138 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2764,7 +2764,7 @@ static bool pfmemalloc_watermark_ok(pg_data_t *pgdat)
/* kswapd must be awake if processes are being throttled */
if (!wmark_ok && waitqueue_active(&pgdat->kswapd_wait)) {
- pgdat->classzone_idx = min(pgdat->classzone_idx,
+ pgdat->kswapd_classzone_idx = min(pgdat->kswapd_classzone_idx,
(enum zone_type)ZONE_NORMAL);
wake_up_interruptible(&pgdat->kswapd_wait);
}
@@ -3248,6 +3248,12 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order,
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
+ /* If kswapd has not been woken recently, then full sleep */
+ if (classzone_idx == -1) {
+ classzone_idx = balanced_classzone_idx = MAX_NR_ZONES - 1;
+ goto full_sleep;
+ }
+
/* Try to sleep for a short interval */
if (prepare_kswapd_sleep(pgdat, order, remaining,
balanced_classzone_idx)) {
@@ -3256,6 +3262,7 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order,
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
}
+full_sleep:
/*
* After a short sleep, check if it was a premature sleep. If not, then
* go fully to sleep until explicitly woken up.
@@ -3316,9 +3323,7 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int order,
*/
static int kswapd(void *p)
{
- unsigned long order, new_order;
- int classzone_idx, new_classzone_idx;
- int balanced_classzone_idx;
+ unsigned int order, classzone_idx;
pg_data_t *pgdat = (pg_data_t*)p;
struct task_struct *tsk = current;
@@ -3348,38 +3353,25 @@ static int kswapd(void *p)
tsk->flags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
set_freezable();
- order = new_order = 0;
- classzone_idx = new_classzone_idx = pgdat->nr_zones - 1;
- balanced_classzone_idx = classzone_idx;
+ pgdat->kswapd_order = order = 0;
+ pgdat->kswapd_classzone_idx = classzone_idx = -1;
for ( ; ; ) {
bool ret;
+kswapd_try_sleep:
+ kswapd_try_to_sleep(pgdat, order, classzone_idx, classzone_idx);
+
/*
- * While we were reclaiming, there might have been another
- * wakeup, so check the values.
+ * Read the new order and classzone_idx which may be -1 if
+ * kswapd_try_to_sleep() woke up after a short timeout instead
+ * of being woken by the page allocator.
*/
- new_order = pgdat->kswapd_max_order;
- new_classzone_idx = pgdat->classzone_idx;
- pgdat->kswapd_max_order = 0;
- pgdat->classzone_idx = pgdat->nr_zones - 1;
-
- if (order < new_order || classzone_idx > new_classzone_idx) {
- /*
- * Don't sleep if someone wants a larger 'order'
- * allocation or has tigher zone constraints
- */
- order = new_order;
- classzone_idx = new_classzone_idx;
- } else {
- kswapd_try_to_sleep(pgdat, order, classzone_idx,
- balanced_classzone_idx);
- order = pgdat->kswapd_max_order;
- classzone_idx = pgdat->classzone_idx;
- new_order = order;
- new_classzone_idx = classzone_idx;
- pgdat->kswapd_max_order = 0;
- pgdat->classzone_idx = pgdat->nr_zones - 1;
- }
+ order = pgdat->kswapd_order;
+ classzone_idx = pgdat->kswapd_classzone_idx;
+ if (classzone_idx == -1)
+ classzone_idx = MAX_NR_ZONES - 1;
+ pgdat->kswapd_order = 0;
+ pgdat->kswapd_classzone_idx = -1;
ret = try_to_freeze();
if (kthread_should_stop())
@@ -3389,12 +3381,19 @@ static int kswapd(void *p)
* We can speed up thawing tasks if we don't call balance_pgdat
* after returning from the refrigerator
*/
- if (!ret) {
- trace_mm_vmscan_kswapd_wake(pgdat->node_id, order);
+ if (ret)
+ continue;
- /* return value ignored until next patch */
- balance_pgdat(pgdat, order, classzone_idx);
- }
+ /*
+ * Try reclaim the requested order but if that fails
+ * then try sleeping on the basis of the order reclaimed.
+ */
+ trace_mm_vmscan_kswapd_wake(pgdat->node_id, order);
+ if (balance_pgdat(pgdat, order, classzone_idx) < order)
+ goto kswapd_try_sleep;
+
+ order = pgdat->kswapd_order;
+ classzone_idx = pgdat->kswapd_classzone_idx;
}
tsk->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD);
@@ -3417,10 +3416,10 @@ void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx)
if (!cpuset_zone_allowed(zone, GFP_KERNEL | __GFP_HARDWALL))
return;
pgdat = zone->zone_pgdat;
- if (pgdat->kswapd_max_order < order) {
- pgdat->kswapd_max_order = order;
- pgdat->classzone_idx = min(pgdat->classzone_idx, classzone_idx);
- }
+ if (pgdat->kswapd_classzone_idx == -1)
+ pgdat->kswapd_classzone_idx = classzone_idx;
+ pgdat->kswapd_classzone_idx = max(pgdat->kswapd_classzone_idx, classzone_idx);
+ pgdat->kswapd_order = max(pgdat->kswapd_order, order);
if (!waitqueue_active(&pgdat->kswapd_wait))
return;
if (zone_balanced(zone, order, 0))
--
2.6.4
[toc] | [prev] | [next] | [standalone]
| From | Mel Gorman <mgorman@techsingularity.net> |
|---|---|
| Date | 2016-04-15 11:20 +0200 |
| Subject | [PATCH 14/27] mm, workingset: Make working set detection node-aware |
| Message-ID | <ro850-In-93@gated-at.bofh.it> |
| In reply to | #1379616 |
Working set and refault detection is still zone-based, fix it.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/mmzone.h | 6 +++---
include/linux/vmstat.h | 1 -
mm/vmstat.c | 20 +++-----------------
mm/workingset.c | 39 ++++++++++++++++++---------------------
4 files changed, 24 insertions(+), 42 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 6f9ceac774af..9a90b918823f 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -139,9 +139,6 @@ enum zone_stat_item {
NUMA_LOCAL, /* allocation from local node */
NUMA_OTHER, /* allocation from other node */
#endif
- WORKINGSET_REFAULT,
- WORKINGSET_ACTIVATE,
- WORKINGSET_NODERECLAIM,
NR_ANON_TRANSPARENT_HUGEPAGES,
NR_FREE_CMA_PAGES,
NR_VM_ZONE_STAT_ITEMS };
@@ -156,6 +153,9 @@ enum node_stat_item {
NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
NR_PAGES_SCANNED, /* pages scanned since last reclaim */
+ WORKINGSET_REFAULT,
+ WORKINGSET_ACTIVATE,
+ WORKINGSET_NODERECLAIM,
NR_VM_NODE_STAT_ITEMS
};
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 41f91a3244a9..24bca20ede8f 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -227,7 +227,6 @@ void mod_node_page_state(struct pglist_data *, enum node_stat_item, long);
void inc_node_page_state(struct page *, enum node_stat_item);
void dec_node_page_state(struct page *, enum node_stat_item);
-extern void inc_zone_state(struct zone *, enum zone_stat_item);
extern void inc_node_state(struct pglist_data *, enum node_stat_item);
extern void __inc_zone_state(struct zone *, enum zone_stat_item);
extern void __inc_node_state(struct pglist_data *, enum node_stat_item);
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 8fbc25ac5859..3cb871ca06e2 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -433,11 +433,6 @@ void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
}
EXPORT_SYMBOL(mod_zone_page_state);
-void inc_zone_state(struct zone *zone, enum zone_stat_item item)
-{
- mod_zone_state(zone, item, 1, 1);
-}
-
void inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
mod_zone_state(page_zone(page), item, 1, 1);
@@ -526,15 +521,6 @@ void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
}
EXPORT_SYMBOL(mod_zone_page_state);
-void inc_zone_state(struct zone *zone, enum zone_stat_item item)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- __inc_zone_state(zone, item);
- local_irq_restore(flags);
-}
-
void inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
unsigned long flags;
@@ -956,9 +942,6 @@ const char * const vmstat_text[] = {
"numa_local",
"numa_other",
#endif
- "workingset_refault",
- "workingset_activate",
- "workingset_nodereclaim",
"nr_anon_transparent_hugepages",
"nr_free_cma",
@@ -971,6 +954,9 @@ const char * const vmstat_text[] = {
"nr_isolated_anon",
"nr_isolated_file",
"nr_pages_scanned",
+ "workingset_refault",
+ "workingset_activate",
+ "workingset_nodereclaim",
/* enum writeback_stat_item counters */
"nr_dirty_threshold",
diff --git a/mm/workingset.c b/mm/workingset.c
index d06d69670b5d..48596c7a910e 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -16,7 +16,7 @@
/*
* Double CLOCK lists
*
- * Per zone, two clock lists are maintained for file pages: the
+ * Per node, two clock lists are maintained for file pages: the
* inactive and the active list. Freshly faulted pages start out at
* the head of the inactive list and page reclaim scans pages from the
* tail. Pages that are accessed multiple times on the inactive list
@@ -141,11 +141,11 @@
*
* Implementation
*
- * For each zone's file LRU lists, a counter for inactive evictions
- * and activations is maintained (zone->inactive_age).
+ * For each node's file LRU lists, a counter for inactive evictions
+ * and activations is maintained (node->inactive_age).
*
* On eviction, a snapshot of this counter (along with some bits to
- * identify the zone) is stored in the now empty page cache radix tree
+ * identify the node) is stored in the now empty page cache radix tree
* slot of the evicted page. This is called a shadow entry.
*
* On cache misses for which there are shadow entries, an eligible
@@ -153,7 +153,7 @@
*/
#define EVICTION_SHIFT (RADIX_TREE_EXCEPTIONAL_ENTRY + \
- ZONES_SHIFT + NODES_SHIFT + \
+ NODES_SHIFT + \
MEM_CGROUP_ID_SHIFT)
#define EVICTION_MASK (~0UL >> EVICTION_SHIFT)
@@ -167,33 +167,30 @@
*/
static unsigned int bucket_order __read_mostly;
-static void *pack_shadow(int memcgid, struct zone *zone, unsigned long eviction)
+static void *pack_shadow(int memcgid, pg_data_t *pgdat, unsigned long eviction)
{
eviction >>= bucket_order;
eviction = (eviction << MEM_CGROUP_ID_SHIFT) | memcgid;
- eviction = (eviction << NODES_SHIFT) | zone_to_nid(zone);
- eviction = (eviction << ZONES_SHIFT) | zone_idx(zone);
+ eviction = (eviction << NODES_SHIFT) | pgdat->node_id;
eviction = (eviction << RADIX_TREE_EXCEPTIONAL_SHIFT);
return (void *)(eviction | RADIX_TREE_EXCEPTIONAL_ENTRY);
}
-static void unpack_shadow(void *shadow, int *memcgidp, struct zone **zonep,
+static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat,
unsigned long *evictionp)
{
unsigned long entry = (unsigned long)shadow;
- int memcgid, nid, zid;
+ int memcgid, nid;
entry >>= RADIX_TREE_EXCEPTIONAL_SHIFT;
- zid = entry & ((1UL << ZONES_SHIFT) - 1);
- entry >>= ZONES_SHIFT;
nid = entry & ((1UL << NODES_SHIFT) - 1);
entry >>= NODES_SHIFT;
memcgid = entry & ((1UL << MEM_CGROUP_ID_SHIFT) - 1);
entry >>= MEM_CGROUP_ID_SHIFT;
*memcgidp = memcgid;
- *zonep = NODE_DATA(nid)->node_zones + zid;
+ *pgdat = NODE_DATA(nid);
*evictionp = entry << bucket_order;
}
@@ -220,7 +217,7 @@ void *workingset_eviction(struct address_space *mapping, struct page *page)
lruvec = mem_cgroup_lruvec(zone->zone_pgdat, memcg);
eviction = atomic_long_inc_return(&lruvec->inactive_age);
- return pack_shadow(memcgid, zone, eviction);
+ return pack_shadow(memcgid, zone->zone_pgdat, eviction);
}
/**
@@ -228,7 +225,7 @@ void *workingset_eviction(struct address_space *mapping, struct page *page)
* @shadow: shadow entry of the evicted page
*
* Calculates and evaluates the refault distance of the previously
- * evicted page in the context of the zone it was allocated in.
+ * evicted page in the context of the node it was allocated in.
*
* Returns %true if the page should be activated, %false otherwise.
*/
@@ -240,10 +237,10 @@ bool workingset_refault(void *shadow)
unsigned long eviction;
struct lruvec *lruvec;
unsigned long refault;
- struct zone *zone;
+ struct pglist_data *pgdat;
int memcgid;
- unpack_shadow(shadow, &memcgid, &zone, &eviction);
+ unpack_shadow(shadow, &memcgid, &pgdat, &eviction);
rcu_read_lock();
/*
@@ -267,7 +264,7 @@ bool workingset_refault(void *shadow)
rcu_read_unlock();
return false;
}
- lruvec = mem_cgroup_lruvec(zone->zone_pgdat, memcg);
+ lruvec = mem_cgroup_lruvec(pgdat, memcg);
refault = atomic_long_read(&lruvec->inactive_age);
active_file = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE);
rcu_read_unlock();
@@ -290,10 +287,10 @@ bool workingset_refault(void *shadow)
*/
refault_distance = (refault - eviction) & EVICTION_MASK;
- inc_zone_state(zone, WORKINGSET_REFAULT);
+ inc_node_state(pgdat, WORKINGSET_REFAULT);
if (refault_distance <= active_file) {
- inc_zone_state(zone, WORKINGSET_ACTIVATE);
+ inc_node_state(pgdat, WORKINGSET_ACTIVATE);
return true;
}
return false;
@@ -435,7 +432,7 @@ static enum lru_status shadow_lru_isolate(struct list_head *item,
}
}
BUG_ON(node->count);
- inc_zone_state(page_zone(virt_to_page(node)), WORKINGSET_NODERECLAIM);
+ inc_node_state(page_zone(virt_to_page(node))->zone_pgdat, WORKINGSET_NODERECLAIM);
if (!__radix_tree_delete_node(&mapping->page_tree, node))
BUG();
--
2.6.4
[toc] | [prev] | [next] | [standalone]
| From | Mel Gorman <mgorman@techsingularity.net> |
|---|---|
| Date | 2016-04-15 11:40 +0200 |
| Subject | [PATCH 01/27] mm, vmstat: Add infrastructure for per-node vmstats |
| Message-ID | <ro8oi-S5-11@gated-at.bofh.it> |
| In reply to | #1379616 |
VM statistic counters for reclaim decisions are zone-based. If the kernel
is to reclaim on a per-node basis then we need to track per-node statistics
but there is no infrastructure for that. The most notable change is that
the old node_page_state is renamed to sum_zone_node_page_state. The new
node_page_state takes a pglist_data and uses per-node stats but none exist
yet. There is some renaming such as vm_stat to vm_zone_stat and the addition
of vm_node_stat and the renaming of mod_state to mod_zone_state. Otherwise,
this is mostly a mechanical patch with no functional change. There is a
lot of similarity between the node and zone helpers which is unfortunate
but there was no obvious way of reusing the code and maintaining type safety.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
drivers/base/node.c | 72 +++++++------
include/linux/mmzone.h | 13 +++
include/linux/vmstat.h | 92 +++++++++++++---
mm/page_alloc.c | 10 +-
mm/vmstat.c | 280 +++++++++++++++++++++++++++++++++++++++++++++----
mm/workingset.c | 9 +-
6 files changed, 403 insertions(+), 73 deletions(-)
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 560751bad294..efb81da250a8 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -74,16 +74,16 @@ static ssize_t node_read_meminfo(struct device *dev,
nid, K(i.totalram),
nid, K(i.freeram),
nid, K(i.totalram - i.freeram),
- nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
- node_page_state(nid, NR_ACTIVE_FILE)),
- nid, K(node_page_state(nid, NR_INACTIVE_ANON) +
- node_page_state(nid, NR_INACTIVE_FILE)),
- nid, K(node_page_state(nid, NR_ACTIVE_ANON)),
- nid, K(node_page_state(nid, NR_INACTIVE_ANON)),
- nid, K(node_page_state(nid, NR_ACTIVE_FILE)),
- nid, K(node_page_state(nid, NR_INACTIVE_FILE)),
- nid, K(node_page_state(nid, NR_UNEVICTABLE)),
- nid, K(node_page_state(nid, NR_MLOCK)));
+ nid, K(sum_zone_node_page_state(nid, NR_ACTIVE_ANON) +
+ sum_zone_node_page_state(nid, NR_ACTIVE_FILE)),
+ nid, K(sum_zone_node_page_state(nid, NR_INACTIVE_ANON) +
+ sum_zone_node_page_state(nid, NR_INACTIVE_FILE)),
+ nid, K(sum_zone_node_page_state(nid, NR_ACTIVE_ANON)),
+ nid, K(sum_zone_node_page_state(nid, NR_INACTIVE_ANON)),
+ nid, K(sum_zone_node_page_state(nid, NR_ACTIVE_FILE)),
+ nid, K(sum_zone_node_page_state(nid, NR_INACTIVE_FILE)),
+ nid, K(sum_zone_node_page_state(nid, NR_UNEVICTABLE)),
+ nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
#ifdef CONFIG_HIGHMEM
n += sprintf(buf + n,
@@ -115,28 +115,28 @@ static ssize_t node_read_meminfo(struct device *dev,
"Node %d AnonHugePages: %8lu kB\n"
#endif
,
- nid, K(node_page_state(nid, NR_FILE_DIRTY)),
- nid, K(node_page_state(nid, NR_WRITEBACK)),
- nid, K(node_page_state(nid, NR_FILE_PAGES)),
- nid, K(node_page_state(nid, NR_FILE_MAPPED)),
- nid, K(node_page_state(nid, NR_ANON_PAGES)),
+ nid, K(sum_zone_node_page_state(nid, NR_FILE_DIRTY)),
+ nid, K(sum_zone_node_page_state(nid, NR_WRITEBACK)),
+ nid, K(sum_zone_node_page_state(nid, NR_FILE_PAGES)),
+ nid, K(sum_zone_node_page_state(nid, NR_FILE_MAPPED)),
+ nid, K(sum_zone_node_page_state(nid, NR_ANON_PAGES)),
nid, K(i.sharedram),
- nid, node_page_state(nid, NR_KERNEL_STACK) *
+ nid, sum_zone_node_page_state(nid, NR_KERNEL_STACK) *
THREAD_SIZE / 1024,
- nid, K(node_page_state(nid, NR_PAGETABLE)),
- nid, K(node_page_state(nid, NR_UNSTABLE_NFS)),
- nid, K(node_page_state(nid, NR_BOUNCE)),
- nid, K(node_page_state(nid, NR_WRITEBACK_TEMP)),
- nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE) +
- node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
- nid, K(node_page_state(nid, NR_SLAB_RECLAIMABLE)),
+ nid, K(sum_zone_node_page_state(nid, NR_PAGETABLE)),
+ nid, K(sum_zone_node_page_state(nid, NR_UNSTABLE_NFS)),
+ nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
+ nid, K(sum_zone_node_page_state(nid, NR_WRITEBACK_TEMP)),
+ nid, K(sum_zone_node_page_state(nid, NR_SLAB_RECLAIMABLE) +
+ sum_zone_node_page_state(nid, NR_SLAB_UNRECLAIMABLE)),
+ nid, K(sum_zone_node_page_state(nid, NR_SLAB_RECLAIMABLE)),
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE))
+ nid, K(sum_zone_node_page_state(nid, NR_SLAB_UNRECLAIMABLE))
, nid,
- K(node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) *
+ K(sum_zone_node_page_state(nid, NR_ANON_TRANSPARENT_HUGEPAGES) *
HPAGE_PMD_NR));
#else
- nid, K(node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
+ nid, K(sum_zone_node_page_state(nid, NR_SLAB_UNRECLAIMABLE)));
#endif
n += hugetlb_report_node_meminfo(nid, buf + n);
return n;
@@ -155,12 +155,12 @@ static ssize_t node_read_numastat(struct device *dev,
"interleave_hit %lu\n"
"local_node %lu\n"
"other_node %lu\n",
- node_page_state(dev->id, NUMA_HIT),
- node_page_state(dev->id, NUMA_MISS),
- node_page_state(dev->id, NUMA_FOREIGN),
- node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
- node_page_state(dev->id, NUMA_LOCAL),
- node_page_state(dev->id, NUMA_OTHER));
+ sum_zone_node_page_state(dev->id, NUMA_HIT),
+ sum_zone_node_page_state(dev->id, NUMA_MISS),
+ sum_zone_node_page_state(dev->id, NUMA_FOREIGN),
+ sum_zone_node_page_state(dev->id, NUMA_INTERLEAVE_HIT),
+ sum_zone_node_page_state(dev->id, NUMA_LOCAL),
+ sum_zone_node_page_state(dev->id, NUMA_OTHER));
}
static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
@@ -168,12 +168,18 @@ static ssize_t node_read_vmstat(struct device *dev,
struct device_attribute *attr, char *buf)
{
int nid = dev->id;
+ struct pglist_data *pgdat = NODE_DATA(nid);
int i;
int n = 0;
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
n += sprintf(buf+n, "%s %lu\n", vmstat_text[i],
- node_page_state(nid, i));
+ sum_zone_node_page_state(nid, i));
+
+ for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+ n += sprintf(buf+n, "%s %lu\n",
+ vmstat_text[i + NR_VM_ZONE_STAT_ITEMS],
+ node_page_state(pgdat, i));
return n;
}
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 48ee8885aa74..16af78ef6c21 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -155,6 +155,10 @@ enum zone_stat_item {
NR_FREE_CMA_PAGES,
NR_VM_ZONE_STAT_ITEMS };
+enum node_stat_item {
+ NR_VM_NODE_STAT_ITEMS
+};
+
/*
* We do arithmetic on the LRU lists in various places in the code,
* so it is important to keep the active lists LRU_ACTIVE higher in
@@ -262,6 +266,11 @@ struct per_cpu_pageset {
#endif
};
+struct per_cpu_nodestat {
+ s8 stat_threshold;
+ s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
+};
+
#endif /* !__GENERATING_BOUNDS.H */
enum zone_type {
@@ -691,6 +700,10 @@ typedef struct pglist_data {
struct list_head split_queue;
unsigned long split_queue_len;
#endif
+
+ /* Per-node vmstats */
+ struct per_cpu_nodestat __percpu *per_cpu_nodestats;
+ atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS];
} pg_data_t;
#define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 152d26b7f972..0f2ecd8ee84a 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -106,20 +106,38 @@ static inline void vm_events_fold_cpu(int cpu)
zone_idx(zone), delta)
/*
- * Zone based page accounting with per cpu differentials.
+ * Zone and node-based page accounting with per cpu differentials.
*/
-extern atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
+extern atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS];
+extern atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS];
static inline void zone_page_state_add(long x, struct zone *zone,
enum zone_stat_item item)
{
atomic_long_add(x, &zone->vm_stat[item]);
- atomic_long_add(x, &vm_stat[item]);
+ atomic_long_add(x, &vm_zone_stat[item]);
+}
+
+static inline void node_page_state_add(long x, struct pglist_data *pgdat,
+ enum node_stat_item item)
+{
+ atomic_long_add(x, &pgdat->vm_stat[item]);
+ atomic_long_add(x, &vm_node_stat[item]);
}
static inline unsigned long global_page_state(enum zone_stat_item item)
{
- long x = atomic_long_read(&vm_stat[item]);
+ long x = atomic_long_read(&vm_zone_stat[item]);
+#ifdef CONFIG_SMP
+ if (x < 0)
+ x = 0;
+#endif
+ return x;
+}
+
+static inline unsigned long global_node_page_state(enum node_stat_item item)
+{
+ long x = atomic_long_read(&vm_node_stat[item]);
#ifdef CONFIG_SMP
if (x < 0)
x = 0;
@@ -161,31 +179,44 @@ static inline unsigned long zone_page_state_snapshot(struct zone *zone,
}
#ifdef CONFIG_NUMA
-
-extern unsigned long node_page_state(int node, enum zone_stat_item item);
-
+extern unsigned long sum_zone_node_page_state(int node,
+ enum zone_stat_item item);
+extern unsigned long node_page_state(struct pglist_data *pgdat,
+ enum node_stat_item item);
#else
-
-#define node_page_state(node, item) global_page_state(item)
-
+#define sum_zone_node_page_state(node, item) global_node_page_state(item)
+#define node_page_state(node, item) global_node_page_state(item)
#endif /* CONFIG_NUMA */
#define add_zone_page_state(__z, __i, __d) mod_zone_page_state(__z, __i, __d)
#define sub_zone_page_state(__z, __i, __d) mod_zone_page_state(__z, __i, -(__d))
+#define add_node_page_state(__p, __i, __d) mod_node_page_state(__p, __i, __d)
+#define sub_node_page_state(__p, __i, __d) mod_node_page_state(__p, __i, -(__d))
#ifdef CONFIG_SMP
void __mod_zone_page_state(struct zone *, enum zone_stat_item item, long);
void __inc_zone_page_state(struct page *, enum zone_stat_item);
void __dec_zone_page_state(struct page *, enum zone_stat_item);
+void __mod_node_page_state(struct pglist_data *, enum node_stat_item item, long);
+void __inc_node_page_state(struct page *, enum node_stat_item);
+void __dec_node_page_state(struct page *, enum node_stat_item);
+
void mod_zone_page_state(struct zone *, enum zone_stat_item, long);
void inc_zone_page_state(struct page *, enum zone_stat_item);
void dec_zone_page_state(struct page *, enum zone_stat_item);
+void mod_node_page_state(struct pglist_data *, enum node_stat_item, long);
+void inc_node_page_state(struct page *, enum node_stat_item);
+void dec_node_page_state(struct page *, enum node_stat_item);
+
extern void inc_zone_state(struct zone *, enum zone_stat_item);
+extern void inc_node_state(struct pglist_data *, enum node_stat_item);
extern void __inc_zone_state(struct zone *, enum zone_stat_item);
+extern void __inc_node_state(struct pglist_data *, enum node_stat_item);
extern void dec_zone_state(struct zone *, enum zone_stat_item);
extern void __dec_zone_state(struct zone *, enum zone_stat_item);
+extern void __dec_node_state(struct pglist_data *, enum node_stat_item);
void quiet_vmstat(void);
void cpu_vm_stats_fold(int cpu);
@@ -209,16 +240,34 @@ static inline void __mod_zone_page_state(struct zone *zone,
zone_page_state_add(delta, zone, item);
}
+static inline void __mod_node_page_state(struct pglist_data *pgdat,
+ enum node_stat_item item, int delta)
+{
+ node_page_state_add(delta, pgdat, item);
+}
+
static inline void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
atomic_long_inc(&zone->vm_stat[item]);
- atomic_long_inc(&vm_stat[item]);
+ atomic_long_inc(&vm_zone_stat[item]);
+}
+
+static inline void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+ atomic_long_inc(&pgdat->vm_stat[item]);
+ atomic_long_inc(&vm_node_stat[item]);
}
static inline void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
{
atomic_long_dec(&zone->vm_stat[item]);
- atomic_long_dec(&vm_stat[item]);
+ atomic_long_dec(&vm_zone_stat[item]);
+}
+
+static inline void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+ atomic_long_dec(&pgdat->vm_stat[item]);
+ atomic_long_dec(&vm_node_stat[item]);
}
static inline void __inc_zone_page_state(struct page *page,
@@ -227,12 +276,26 @@ static inline void __inc_zone_page_state(struct page *page,
__inc_zone_state(page_zone(page), item);
}
+static inline void __inc_node_page_state(struct page *page,
+ enum node_stat_item item)
+{
+ __inc_node_state(page_zone(page)->zone_pgdat, item);
+}
+
+
static inline void __dec_zone_page_state(struct page *page,
enum zone_stat_item item)
{
__dec_zone_state(page_zone(page), item);
}
+static inline void __dec_node_page_state(struct page *page,
+ enum node_stat_item item)
+{
+ __dec_node_state(page_zone(page)->zone_pgdat, item);
+}
+
+
/*
* We only use atomic operations to update counters. So there is no need to
* disable interrupts.
@@ -241,7 +304,12 @@ static inline void __dec_zone_page_state(struct page *page,
#define dec_zone_page_state __dec_zone_page_state
#define mod_zone_page_state __mod_zone_page_state
+#define inc_node_page_state __inc_node_page_state
+#define dec_node_page_state __dec_node_page_state
+#define mod_node_page_state __mod_node_page_state
+
#define inc_zone_state __inc_zone_state
+#define inc_node_state __inc_node_state
#define dec_zone_state __dec_zone_state
#define set_pgdat_percpu_threshold(pgdat, callback) { }
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 147c0d55ed32..6a9f71320d35 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4056,8 +4056,8 @@ void si_meminfo_node(struct sysinfo *val, int nid)
for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++)
managed_pages += pgdat->node_zones[zone_type].managed_pages;
val->totalram = managed_pages;
- val->sharedram = node_page_state(nid, NR_SHMEM);
- val->freeram = node_page_state(nid, NR_FREE_PAGES);
+ val->sharedram = sum_zone_node_page_state(nid, NR_SHMEM);
+ val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
#ifdef CONFIG_HIGHMEM
val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages;
val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
@@ -5156,6 +5156,11 @@ static void __meminit setup_zone_pageset(struct zone *zone)
zone->pageset = alloc_percpu(struct per_cpu_pageset);
for_each_possible_cpu(cpu)
zone_pageset_init(zone, cpu);
+
+ if (!zone->zone_pgdat->per_cpu_nodestats) {
+ zone->zone_pgdat->per_cpu_nodestats =
+ alloc_percpu(struct per_cpu_nodestat);
+ }
}
/*
@@ -5859,6 +5864,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
reset_deferred_meminit(pgdat);
pgdat->node_id = nid;
pgdat->node_start_pfn = node_start_pfn;
+ pgdat->per_cpu_nodestats = NULL;
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 20698fc82354..2e90f17d222d 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -86,8 +86,10 @@ void vm_events_fold_cpu(int cpu)
*
* vm_stat contains the global counters
*/
-atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
-EXPORT_SYMBOL(vm_stat);
+atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
+atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS] __cacheline_aligned_in_smp;
+EXPORT_SYMBOL(vm_zone_stat);
+EXPORT_SYMBOL(vm_node_stat);
#ifdef CONFIG_SMP
@@ -176,9 +178,13 @@ void refresh_zone_stat_thresholds(void)
threshold = calculate_normal_threshold(zone);
- for_each_online_cpu(cpu)
+ for_each_online_cpu(cpu) {
+ struct pglist_data *pgdat = zone->zone_pgdat;
per_cpu_ptr(zone->pageset, cpu)->stat_threshold
= threshold;
+ per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold
+ = threshold;
+ }
/*
* Only set percpu_drift_mark if there is a danger that
@@ -238,6 +244,26 @@ void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
}
EXPORT_SYMBOL(__mod_zone_page_state);
+void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
+ long delta)
+{
+ struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+ s8 __percpu *p = pcp->vm_node_stat_diff + item;
+ long x;
+ long t;
+
+ x = delta + __this_cpu_read(*p);
+
+ t = __this_cpu_read(pcp->stat_threshold);
+
+ if (unlikely(x > t || x < -t)) {
+ node_page_state_add(x, pgdat, item);
+ x = 0;
+ }
+ __this_cpu_write(*p, x);
+}
+EXPORT_SYMBOL(__mod_node_page_state);
+
/*
* Optimized increment and decrement functions.
*
@@ -277,12 +303,34 @@ void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
}
}
+void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+ struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+ s8 __percpu *p = pcp->vm_node_stat_diff + item;
+ s8 v, t;
+
+ v = __this_cpu_inc_return(*p);
+ t = __this_cpu_read(pcp->stat_threshold);
+ if (unlikely(v > t)) {
+ s8 overstep = t >> 1;
+
+ node_page_state_add(v + overstep, pgdat, item);
+ __this_cpu_write(*p, -overstep);
+ }
+}
+
void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
__inc_zone_state(page_zone(page), item);
}
EXPORT_SYMBOL(__inc_zone_page_state);
+void __inc_node_page_state(struct page *page, enum node_stat_item item)
+{
+ __inc_node_state(page_zone(page)->zone_pgdat, item);
+}
+EXPORT_SYMBOL(__inc_node_page_state);
+
void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
{
struct per_cpu_pageset __percpu *pcp = zone->pageset;
@@ -299,12 +347,34 @@ void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
}
}
+void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+ struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+ s8 __percpu *p = pcp->vm_node_stat_diff + item;
+ s8 v, t;
+
+ v = __this_cpu_dec_return(*p);
+ t = __this_cpu_read(pcp->stat_threshold);
+ if (unlikely(v < - t)) {
+ s8 overstep = t >> 1;
+
+ node_page_state_add(v - overstep, pgdat, item);
+ __this_cpu_write(*p, overstep);
+ }
+}
+
void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
__dec_zone_state(page_zone(page), item);
}
EXPORT_SYMBOL(__dec_zone_page_state);
+void __dec_node_page_state(struct page *page, enum node_stat_item item)
+{
+ __dec_node_state(page_zone(page)->zone_pgdat, item);
+}
+EXPORT_SYMBOL(__dec_node_page_state);
+
#ifdef CONFIG_HAVE_CMPXCHG_LOCAL
/*
* If we have cmpxchg_local support then we do not need to incur the overhead
@@ -318,8 +388,8 @@ EXPORT_SYMBOL(__dec_zone_page_state);
* 1 Overstepping half of threshold
* -1 Overstepping minus half of threshold
*/
-static inline void mod_state(struct zone *zone, enum zone_stat_item item,
- long delta, int overstep_mode)
+static inline void mod_zone_state(struct zone *zone,
+ enum zone_stat_item item, long delta, int overstep_mode)
{
struct per_cpu_pageset __percpu *pcp = zone->pageset;
s8 __percpu *p = pcp->vm_stat_diff + item;
@@ -359,26 +429,88 @@ static inline void mod_state(struct zone *zone, enum zone_stat_item item,
void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
long delta)
{
- mod_state(zone, item, delta, 0);
+ mod_zone_state(zone, item, delta, 0);
}
EXPORT_SYMBOL(mod_zone_page_state);
void inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
- mod_state(zone, item, 1, 1);
+ mod_zone_state(zone, item, 1, 1);
}
void inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
- mod_state(page_zone(page), item, 1, 1);
+ mod_zone_state(page_zone(page), item, 1, 1);
}
EXPORT_SYMBOL(inc_zone_page_state);
void dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
- mod_state(page_zone(page), item, -1, -1);
+ mod_zone_state(page_zone(page), item, -1, -1);
}
EXPORT_SYMBOL(dec_zone_page_state);
+
+static inline void mod_node_state(struct pglist_data *pgdat,
+ enum node_stat_item item, int delta, int overstep_mode)
+{
+ struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+ s8 __percpu *p = pcp->vm_node_stat_diff + item;
+ long o, n, t, z;
+
+ do {
+ z = 0; /* overflow to zone counters */
+
+ /*
+ * The fetching of the stat_threshold is racy. We may apply
+ * a counter threshold to the wrong the cpu if we get
+ * rescheduled while executing here. However, the next
+ * counter update will apply the threshold again and
+ * therefore bring the counter under the threshold again.
+ *
+ * Most of the time the thresholds are the same anyways
+ * for all cpus in a zone.
+ */
+ t = this_cpu_read(pcp->stat_threshold);
+
+ o = this_cpu_read(*p);
+ n = delta + o;
+
+ if (n > t || n < -t) {
+ int os = overstep_mode * (t >> 1) ;
+
+ /* Overflow must be added to zone counters */
+ z = n + os;
+ n = -os;
+ }
+ } while (this_cpu_cmpxchg(*p, o, n) != o);
+
+ if (z)
+ node_page_state_add(z, pgdat, item);
+}
+
+void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
+ long delta)
+{
+ mod_node_state(pgdat, item, delta, 0);
+}
+EXPORT_SYMBOL(mod_node_page_state);
+
+void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+ mod_node_state(pgdat, item, 1, 1);
+}
+
+void inc_node_page_state(struct page *page, enum node_stat_item item)
+{
+ mod_node_state(page_zone(page)->zone_pgdat, item, 1, 1);
+}
+EXPORT_SYMBOL(inc_node_page_state);
+
+void dec_node_page_state(struct page *page, enum node_stat_item item)
+{
+ mod_node_state(page_zone(page)->zone_pgdat, item, -1, -1);
+}
+EXPORT_SYMBOL(dec_node_page_state);
#else
/*
* Use interrupt disable to serialize counter updates
@@ -424,21 +556,69 @@ void dec_zone_page_state(struct page *page, enum zone_stat_item item)
local_irq_restore(flags);
}
EXPORT_SYMBOL(dec_zone_page_state);
-#endif
+void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __inc_node_state(pgdat, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(inc_node_state);
+
+void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
+ long delta)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __mod_node_page_state(pgdat, item, delta);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(mod_node_page_state);
+
+void inc_node_page_state(struct page *page, enum node_stat_item item)
+{
+ unsigned long flags;
+ struct pglist_data *pgdat;
+
+ pgdat = page_zone(page)->zone_pgdat;
+ local_irq_save(flags);
+ __inc_node_state(pgdat, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(inc_node_page_state);
+
+void dec_node_page_state(struct page *page, enum node_stat_item item)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __dec_node_page_state(page, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(dec_node_page_state);
+#endif
/*
* Fold a differential into the global counters.
* Returns the number of counters updated.
*/
-static int fold_diff(int *diff)
+static int fold_diff(int *zone_diff, int *node_diff)
{
int i;
int changes = 0;
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
- if (diff[i]) {
- atomic_long_add(diff[i], &vm_stat[i]);
+ if (zone_diff[i]) {
+ atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
+ changes++;
+ }
+
+ for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+ if (node_diff[i]) {
+ atomic_long_add(node_diff[i], &vm_node_stat[i]);
changes++;
}
return changes;
@@ -462,9 +642,11 @@ static int fold_diff(int *diff)
*/
static int refresh_cpu_vm_stats(bool do_pagesets)
{
+ struct pglist_data *pgdat;
struct zone *zone;
int i;
- int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+ int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+ int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
int changes = 0;
for_each_populated_zone(zone) {
@@ -477,7 +659,7 @@ static int refresh_cpu_vm_stats(bool do_pagesets)
if (v) {
atomic_long_add(v, &zone->vm_stat[i]);
- global_diff[i] += v;
+ global_zone_diff[i] += v;
#ifdef CONFIG_NUMA
/* 3 seconds idle till flush */
__this_cpu_write(p->expire, 3);
@@ -516,7 +698,22 @@ static int refresh_cpu_vm_stats(bool do_pagesets)
}
#endif
}
- changes += fold_diff(global_diff);
+
+ for_each_online_pgdat(pgdat) {
+ struct per_cpu_nodestat __percpu *p = pgdat->per_cpu_nodestats;
+
+ for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
+ int v;
+
+ v = this_cpu_xchg(p->vm_node_stat_diff[i], 0);
+ if (v) {
+ atomic_long_add(v, &pgdat->vm_stat[i]);
+ global_node_diff[i] += v;
+ }
+ }
+ }
+
+ changes += fold_diff(global_zone_diff, global_node_diff);
return changes;
}
@@ -527,9 +724,11 @@ static int refresh_cpu_vm_stats(bool do_pagesets)
*/
void cpu_vm_stats_fold(int cpu)
{
+ struct pglist_data *pgdat;
struct zone *zone;
int i;
- int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+ int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+ int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
for_each_populated_zone(zone) {
struct per_cpu_pageset *p;
@@ -543,11 +742,27 @@ void cpu_vm_stats_fold(int cpu)
v = p->vm_stat_diff[i];
p->vm_stat_diff[i] = 0;
atomic_long_add(v, &zone->vm_stat[i]);
- global_diff[i] += v;
+ global_zone_diff[i] += v;
}
}
- fold_diff(global_diff);
+ for_each_online_pgdat(pgdat) {
+ struct per_cpu_nodestat *p;
+
+ p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu);
+
+ for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+ if (p->vm_node_stat_diff[i]) {
+ int v;
+
+ v = p->vm_node_stat_diff[i];
+ p->vm_node_stat_diff[i] = 0;
+ atomic_long_add(v, &pgdat->vm_stat[i]);
+ global_node_diff[i] += v;
+ }
+ }
+
+ fold_diff(global_zone_diff, global_node_diff);
}
/*
@@ -563,16 +778,19 @@ void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
int v = pset->vm_stat_diff[i];
pset->vm_stat_diff[i] = 0;
atomic_long_add(v, &zone->vm_stat[i]);
- atomic_long_add(v, &vm_stat[i]);
+ atomic_long_add(v, &vm_zone_stat[i]);
}
}
#endif
#ifdef CONFIG_NUMA
/*
- * Determine the per node value of a stat item.
+ * Determine the per node value of a stat item. This function
+ * is called frequently in a NUMA machine, so try to be as
+ * frugal as possible.
*/
-unsigned long node_page_state(int node, enum zone_stat_item item)
+unsigned long sum_zone_node_page_state(int node,
+ enum zone_stat_item item)
{
struct zone *zones = NODE_DATA(node)->node_zones;
@@ -590,6 +808,19 @@ unsigned long node_page_state(int node, enum zone_stat_item item)
zone_page_state(&zones[ZONE_MOVABLE], item);
}
+/*
+ * Determine the per node value of a stat item.
+ */
+unsigned long node_page_state(struct pglist_data *pgdat,
+ enum node_stat_item item)
+{
+ long x = atomic_long_read(&pgdat->vm_stat[item]);
+#ifdef CONFIG_SMP
+ if (x < 0)
+ x = 0;
+#endif
+ return x;
+}
#endif
#ifdef CONFIG_COMPACTION
@@ -1278,6 +1509,7 @@ static void *vmstat_start(struct seq_file *m, loff_t *pos)
if (*pos >= ARRAY_SIZE(vmstat_text))
return NULL;
stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
+ NR_VM_NODE_STAT_ITEMS * sizeof(unsigned long) +
NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
#ifdef CONFIG_VM_EVENT_COUNTERS
@@ -1292,6 +1524,10 @@ static void *vmstat_start(struct seq_file *m, loff_t *pos)
v[i] = global_page_state(i);
v += NR_VM_ZONE_STAT_ITEMS;
+ for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+ v[i] = global_node_page_state(i);
+ v += NR_VM_NODE_STAT_ITEMS;
+
global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
v + NR_DIRTY_THRESHOLD);
v += NR_VM_WRITEBACK_STAT_ITEMS;
diff --git a/mm/workingset.c b/mm/workingset.c
index 8a75f8d2916a..ac36efa8c754 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -349,12 +349,13 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
shadow_nodes = list_lru_shrink_count(&workingset_shadow_nodes, sc);
local_irq_enable();
- if (memcg_kmem_enabled())
+ if (memcg_kmem_enabled()) {
pages = mem_cgroup_node_nr_lru_pages(sc->memcg, sc->nid,
LRU_ALL_FILE);
- else
- pages = node_page_state(sc->nid, NR_ACTIVE_FILE) +
- node_page_state(sc->nid, NR_INACTIVE_FILE);
+ } else {
+ pages = sum_zone_node_page_state(sc->nid, NR_ACTIVE_FILE) +
+ sum_zone_node_page_state(sc->nid, NR_INACTIVE_FILE);
+ }
/*
* Active cache pages are limited to 50% of memory, and shadow
--
2.6.4
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