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author | Ken Chen <kenchen@google.com> | 2007-10-16 23:30:38 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-17 08:43:02 -0700 |
commit | 0e0f4fc22ece8e593167eccbb1a4154565c11faa (patch) | |
tree | 564ab2eabb31ab945c334706662854bb227f45e9 /fs/super.c | |
parent | 670e4def6ef5f44315d62748134e535b479c784f (diff) | |
download | linux-stable-0e0f4fc22ece8e593167eccbb1a4154565c11faa.tar.gz linux-stable-0e0f4fc22ece8e593167eccbb1a4154565c11faa.tar.bz2 linux-stable-0e0f4fc22ece8e593167eccbb1a4154565c11faa.zip |
writeback: fix periodic superblock dirty inode flushing
Current -mm tree has bucketful of bug fixes in periodic writeback path.
However, we still hit a glitch where dirty pages on a given inode aren't
completely flushed to the disk, and system will accumulate large amount of
dirty pages beyond what dirty_expire_interval is designed for.
The problem is __sync_single_inode() will move an inode to sb->s_dirty list
even when there are more pending dirty pages on that inode. If there is
another inode with a small number of dirty pages, we hit a case where the loop
iteration in wb_kupdate() terminates prematurely because wbc.nr_to_write > 0.
Thus leaving the inode that has large amount of dirty pages behind and it has
to wait for another dirty_writeback_interval before we flush it again. We
effectively only write out MAX_WRITEBACK_PAGES every dirty_writeback_interval.
If the rate of dirtying is sufficiently high, the system will start
accumulate a large number of dirty pages.
So fix it by having another sb->s_more_io list on which to park the inode
while we iterate through sb->s_io and to allow each dirty inode which resides
on that sb to have an equal chance of flushing some amount of dirty pages.
Signed-off-by: Ken Chen <kenchen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/super.c')
-rw-r--r-- | fs/super.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/super.c b/fs/super.c index fc8ebedc6bed..1bfcca2104be 100644 --- a/fs/super.c +++ b/fs/super.c @@ -67,6 +67,7 @@ static struct super_block *alloc_super(struct file_system_type *type) } INIT_LIST_HEAD(&s->s_dirty); INIT_LIST_HEAD(&s->s_io); + INIT_LIST_HEAD(&s->s_more_io); INIT_LIST_HEAD(&s->s_files); INIT_LIST_HEAD(&s->s_instances); INIT_HLIST_HEAD(&s->s_anon); |