diff options
| author | Dave Chinner <dchinner@redhat.com> | 2016-07-26 15:21:50 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-26 16:19:19 -0700 |
| commit | 6c60d2b5746cf23025ffe71bd7ff9075048fc90c (patch) | |
| tree | 6794888cf362aa86c079ed5697c1ef7a6c117a1a /include/linux/writeback.h | |
| parent | 7d65b27448a90e08270537234819563e07936f76 (diff) | |
fs/fs-writeback.c: add a new writeback list for sync
wait_sb_inodes() currently does a walk of all inodes in the filesystem
to find dirty one to wait on during sync. This is highly inefficient
and wastes a lot of CPU when there are lots of clean cached inodes that
we don't need to wait on.
To avoid this "all inode" walk, we need to track inodes that are
currently under writeback that we need to wait for. We do this by
adding inodes to a writeback list on the sb when the mapping is first
tagged as having pages under writeback. wait_sb_inodes() can then walk
this list of "inodes under IO" and wait specifically just for the inodes
that the current sync(2) needs to wait for.
Define a couple helpers to add/remove an inode from the writeback list
and call them when the overall mapping is tagged for or cleared from
writeback. Update wait_sb_inodes() to walk only the inodes under
writeback due to the sync.
With this change, filesystem sync times are significantly reduced for
fs' with largely populated inode caches and otherwise no other work to
do. For example, on a 16xcpu 2GHz x86-64 server, 10TB XFS filesystem
with a ~10m entry inode cache, sync times are reduced from ~7.3s to less
than 0.1s when the filesystem is fully clean.
Link: http://lkml.kernel.org/r/1466594593-6757-2-git-send-email-bfoster@redhat.com
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Holger Hoffstätte <holger.hoffstaette@applied-asynchrony.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/writeback.h')
| -rw-r--r-- | include/linux/writeback.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/writeback.h b/include/linux/writeback.h index d0b5ca5d4e08..717e6149e753 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -384,4 +384,7 @@ void tag_pages_for_writeback(struct address_space *mapping, void account_page_redirty(struct page *page); +void sb_mark_inode_writeback(struct inode *inode); +void sb_clear_inode_writeback(struct inode *inode); + #endif /* WRITEBACK_H */ |