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| author | Mel Gorman <mgorman@suse.de> | 2012-01-12 17:19:34 -0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-08-02 14:37:30 +0100 |
| commit | 419276781056d8942c97b11447b8302d739e8c64 (patch) | |
| tree | 4646bd7d3374216aff1384e719f243322e5cf0d7 /fs/nfs | |
| parent | 46aadfff5c7660f3736c7330952c380d58aacec5 (diff) | |
| download | lwn-419276781056d8942c97b11447b8302d739e8c64.tar.gz lwn-419276781056d8942c97b11447b8302d739e8c64.zip | |
mm: compaction: determine if dirty pages can be migrated without blocking within ->migratepage
commit b969c4ab9f182a6e1b2a0848be349f99714947b0 upstream.
Stable note: Not tracked in Bugzilla. A fix aimed at preserving page
aging information by reducing LRU list churning had the side-effect
of reducing THP allocation success rates. This was part of a series
to restore the success rates while preserving the reclaim fix.
Asynchronous compaction is used when allocating transparent hugepages to
avoid blocking for long periods of time. Due to reports of stalling,
there was a debate on disabling synchronous compaction but this severely
impacted allocation success rates. Part of the reason was that many dirty
pages are skipped in asynchronous compaction by the following check;
if (PageDirty(page) && !sync &&
mapping->a_ops->migratepage != migrate_page)
rc = -EBUSY;
This skips over all mapping aops using buffer_migrate_page() even though
it is possible to migrate some of these pages without blocking. This
patch updates the ->migratepage callback with a "sync" parameter. It is
the responsibility of the callback to fail gracefully if migration would
block.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/internal.h | 2 | ||||
| -rw-r--r-- | fs/nfs/write.c | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 3f4d95751d52..8d96ed6af6db 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -330,7 +330,7 @@ void nfs_commit_release_pages(struct nfs_write_data *data); #ifdef CONFIG_MIGRATION extern int nfs_migrate_page(struct address_space *, - struct page *, struct page *); + struct page *, struct page *, bool); #else #define nfs_migrate_page NULL #endif diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 4efd42166992..31b246194f87 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1711,7 +1711,7 @@ out_error: #ifdef CONFIG_MIGRATION int nfs_migrate_page(struct address_space *mapping, struct page *newpage, - struct page *page) + struct page *page, bool sync) { /* * If PagePrivate is set, then the page is currently associated with @@ -1726,7 +1726,7 @@ int nfs_migrate_page(struct address_space *mapping, struct page *newpage, nfs_fscache_release_page(page, GFP_KERNEL); - return migrate_page(mapping, newpage, page); + return migrate_page(mapping, newpage, page, sync); } #endif |