From b969c4ab9f182a6e1b2a0848be349f99714947b0 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 12 Jan 2012 17:19:34 -0800 Subject: mm: compaction: determine if dirty pages can be migrated without blocking within ->migratepage 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 Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Minchan Kim Cc: Dave Jones Cc: Jan Kara Cc: Andy Isaacson Cc: Nai Xia Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/btrfs/disk-io.c | 4 ++-- fs/hugetlbfs/inode.c | 3 ++- fs/nfs/internal.h | 2 +- fs/nfs/write.c | 4 ++-- 4 files changed, 7 insertions(+), 6 deletions(-) (limited to 'fs') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index f99a099a7747..1375494c8cb6 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -872,7 +872,7 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, #ifdef CONFIG_MIGRATION static int btree_migratepage(struct address_space *mapping, - struct page *newpage, struct page *page) + struct page *newpage, struct page *page, bool sync) { /* * we can't safely write a btree page from here, @@ -887,7 +887,7 @@ static int btree_migratepage(struct address_space *mapping, if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) return -EAGAIN; - return migrate_page(mapping, newpage, page); + return migrate_page(mapping, newpage, page, sync); } #endif diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index e425ad9d0490..06fd4608a990 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -583,7 +583,8 @@ static int hugetlbfs_set_page_dirty(struct page *page) } static int hugetlbfs_migrate_page(struct address_space *mapping, - struct page *newpage, struct page *page) + struct page *newpage, struct page *page, + bool sync) { int rc; diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 5ee92538b063..114398a15830 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -332,7 +332,7 @@ 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 0c3885255f97..889e98bc5a21 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1688,7 +1688,7 @@ 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 @@ -1703,7 +1703,7 @@ 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 -- cgit v1.2.3