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Groups > linux.kernel > #1493772
| From | Ross Zwisler <ross.zwisler@linux.intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v4 07/12] dax: coordinate locking for offsets in PMD range |
| Date | 2016-09-30 01:00 +0200 |
| Message-ID | <smSt3-1Wd-7@gated-at.bofh.it> (permalink) |
| References | <smSjo-1SH-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
DAX radix tree locking currently locks entries based on the unique
combination of the 'mapping' pointer and the pgoff_t 'index' for the entry.
This works for PTEs, but as we move to PMDs we will need to have all the
offsets within the range covered by the PMD to map to the same bit lock.
To accomplish this, for ranges covered by a PMD entry we will instead lock
based on the page offset of the beginning of the PMD entry. The 'mapping'
pointer is still used in the same way.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
---
fs/dax.c | 37 ++++++++++++++++++++++++-------------
include/linux/dax.h | 2 +-
mm/filemap.c | 2 +-
3 files changed, 26 insertions(+), 15 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index baef586..406feea 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -64,10 +64,17 @@ static int __init init_dax_wait_table(void)
}
fs_initcall(init_dax_wait_table);
+static pgoff_t dax_entry_start(pgoff_t index, void *entry)
+{
+ if (RADIX_DAX_TYPE(entry) == RADIX_DAX_PMD)
+ index &= (PMD_MASK >> PAGE_SHIFT);
+ return index;
+}
+
static wait_queue_head_t *dax_entry_waitqueue(struct address_space *mapping,
- pgoff_t index)
+ pgoff_t entry_start)
{
- unsigned long hash = hash_long((unsigned long)mapping ^ index,
+ unsigned long hash = hash_long((unsigned long)mapping ^ entry_start,
DAX_WAIT_TABLE_BITS);
return wait_table + hash;
}
@@ -285,7 +292,7 @@ EXPORT_SYMBOL_GPL(dax_do_io);
*/
struct exceptional_entry_key {
struct address_space *mapping;
- unsigned long index;
+ pgoff_t entry_start;
};
struct wait_exceptional_entry_queue {
@@ -301,7 +308,7 @@ static int wake_exceptional_entry_func(wait_queue_t *wait, unsigned int mode,
container_of(wait, struct wait_exceptional_entry_queue, wait);
if (key->mapping != ewait->key.mapping ||
- key->index != ewait->key.index)
+ key->entry_start != ewait->key.entry_start)
return 0;
return autoremove_wake_function(wait, mode, sync, NULL);
}
@@ -359,12 +366,10 @@ static void *get_unlocked_mapping_entry(struct address_space *mapping,
{
void *entry, **slot;
struct wait_exceptional_entry_queue ewait;
- wait_queue_head_t *wq = dax_entry_waitqueue(mapping, index);
+ wait_queue_head_t *wq;
init_wait(&ewait.wait);
ewait.wait.func = wake_exceptional_entry_func;
- ewait.key.mapping = mapping;
- ewait.key.index = index;
for (;;) {
entry = __radix_tree_lookup(&mapping->page_tree, index, NULL,
@@ -375,6 +380,11 @@ static void *get_unlocked_mapping_entry(struct address_space *mapping,
*slotp = slot;
return entry;
}
+
+ wq = dax_entry_waitqueue(mapping,
+ dax_entry_start(index, entry));
+ ewait.key.mapping = mapping;
+ ewait.key.entry_start = dax_entry_start(index, entry);
prepare_to_wait_exclusive(wq, &ewait.wait,
TASK_UNINTERRUPTIBLE);
spin_unlock_irq(&mapping->tree_lock);
@@ -447,10 +457,11 @@ restart:
return entry;
}
-void dax_wake_mapping_entry_waiter(struct address_space *mapping,
+void dax_wake_mapping_entry_waiter(void *entry, struct address_space *mapping,
pgoff_t index, bool wake_all)
{
- wait_queue_head_t *wq = dax_entry_waitqueue(mapping, index);
+ wait_queue_head_t *wq = dax_entry_waitqueue(mapping,
+ dax_entry_start(index, entry));
/*
* Checking for locked entry and prepare_to_wait_exclusive() happens
@@ -462,7 +473,7 @@ void dax_wake_mapping_entry_waiter(struct address_space *mapping,
struct exceptional_entry_key key;
key.mapping = mapping;
- key.index = index;
+ key.entry_start = dax_entry_start(index, entry);
__wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key);
}
}
@@ -480,7 +491,7 @@ void dax_unlock_mapping_entry(struct address_space *mapping, pgoff_t index)
}
unlock_slot(mapping, slot);
spin_unlock_irq(&mapping->tree_lock);
- dax_wake_mapping_entry_waiter(mapping, index, false);
+ dax_wake_mapping_entry_waiter(entry, mapping, index, false);
}
static void put_locked_mapping_entry(struct address_space *mapping,
@@ -505,7 +516,7 @@ static void put_unlocked_mapping_entry(struct address_space *mapping,
return;
/* We have to wake up next waiter for the radix tree entry lock */
- dax_wake_mapping_entry_waiter(mapping, index, false);
+ dax_wake_mapping_entry_waiter(entry, mapping, index, false);
}
/*
@@ -532,7 +543,7 @@ int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index)
radix_tree_delete(&mapping->page_tree, index);
mapping->nrexceptional--;
spin_unlock_irq(&mapping->tree_lock);
- dax_wake_mapping_entry_waiter(mapping, index, true);
+ dax_wake_mapping_entry_waiter(entry, mapping, index, true);
return 1;
}
diff --git a/include/linux/dax.h b/include/linux/dax.h
index add6c4b..4065601 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -21,7 +21,7 @@ int iomap_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
struct iomap_ops *ops);
int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
-void dax_wake_mapping_entry_waiter(struct address_space *mapping,
+void dax_wake_mapping_entry_waiter(void *entry, struct address_space *mapping,
pgoff_t index, bool wake_all);
#ifdef CONFIG_FS_DAX
diff --git a/mm/filemap.c b/mm/filemap.c
index 8a287df..35e880d 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -617,7 +617,7 @@ static int page_cache_tree_insert(struct address_space *mapping,
if (node)
workingset_node_pages_dec(node);
/* Wakeup waiters for exceptional entry lock */
- dax_wake_mapping_entry_waiter(mapping, page->index,
+ dax_wake_mapping_entry_waiter(p, mapping, page->index,
false);
}
}
--
2.7.4
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[PATCH v4 00/12] re-enable DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 00:50 +0200
[PATCH v4 06/12] dax: consistent variable naming for DAX entries Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 06/12] dax: consistent variable naming for DAX entries Jan Kara <jack@suse.cz> - 2016-10-03 11:40 +0200
[PATCH v4 02/12] ext4: tell DAX the size of allocation holes Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
[PATCH v4 05/12] dax: make 'wait_table' global variable static Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 05/12] dax: make 'wait_table' global variable static Jan Kara <jack@suse.cz> - 2016-10-03 11:40 +0200
[PATCH v4 12/12] dax: remove "depends on BROKEN" from FS_DAX_PMD Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
[PATCH v4 09/12] dax: correct dax iomap code namespace Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 09/12] dax: correct dax iomap code namespace Christoph Hellwig <hch@lst.de> - 2016-09-30 11:00 +0200
Re: [PATCH v4 09/12] dax: correct dax iomap code namespace Jan Kara <jack@suse.cz> - 2016-10-03 12:00 +0200
[PATCH v4 07/12] dax: coordinate locking for offsets in PMD range Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 07/12] dax: coordinate locking for offsets in PMD range Christoph Hellwig <hch@infradead.org> - 2016-09-30 11:50 +0200
Re: [PATCH v4 07/12] dax: coordinate locking for offsets in PMD range Jan Kara <jack@suse.cz> - 2016-10-03 12:00 +0200
Re: [PATCH v4 07/12] dax: coordinate locking for offsets in PMD range Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-03 20:50 +0200
[PATCH v4 01/12] ext4: allow DAX writeback for hole punch Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
[PATCH v4 04/12] ext2: remove support for DAX PMD faults Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 04/12] ext2: remove support for DAX PMD faults Jan Kara <jack@suse.cz> - 2016-10-03 11:40 +0200
[PATCH v4 03/12] dax: remove buffer_size_valid() Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 03/12] dax: remove buffer_size_valid() Christoph Hellwig <hch@lst.de> - 2016-09-30 10:50 +0200
[PATCH v4 11/12] xfs: use struct iomap based DAX PMD fault path Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
[PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Christoph Hellwig <hch@infradead.org> - 2016-09-30 12:00 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-03 23:20 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Jan Kara <jack@suse.cz> - 2016-10-03 13:10 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Christoph Hellwig <hch@lst.de> - 2016-10-03 18:40 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-03 23:10 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Jan Kara <jack@suse.cz> - 2016-10-04 08:00 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-04 17:40 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Jan Kara <jack@suse.cz> - 2016-10-05 08:00 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-06 23:40 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-07 05:00 +0200
Re: [PATCH v4 10/12] dax: add struct iomap based DAX PMD support Jan Kara <jack@suse.cz> - 2016-10-07 09:50 +0200
[PATCH v4 08/12] dax: remove dax_pmd_fault() Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 01:00 +0200
Re: [PATCH v4 08/12] dax: remove dax_pmd_fault() Jan Kara <jack@suse.cz> - 2016-10-03 12:00 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Dave Chinner <david@fromorbit.com> - 2016-09-30 01:50 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-09-30 05:10 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support "Darrick J. Wong" <darrick.wong@oracle.com> - 2016-09-30 06:10 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-03 21:00 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Dave Chinner <david@fromorbit.com> - 2016-09-30 08:50 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-03 23:20 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Ross Zwisler <ross.zwisler@linux.intel.com> - 2016-10-04 01:10 +0200
Re: [PATCH v4 00/12] re-enable DAX PMD support Christoph Hellwig <hch@infradead.org> - 2016-09-30 13:50 +0200
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