path: root/fs
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-11 13:37:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-12 11:13:07 -0700
commit505a666ee3fc611518e85df203eb8c707995ceaa (patch)
treec4df72f1504a245d027e7c3c7617e3d08c0c7385 /fs
parent0ba13fd19d39b7cb672bcec052bc813389c079a4 (diff)
writeback: plug writeback in wb_writeback() and writeback_inodes_wb()
We had to revert the pluggin in writeback_sb_inodes() because the wb->list_lock is held, but we could easily plug at a higher level before taking that lock, and unplug after releasing it. This does that. Chris will run performance numbers, just to verify that this approach is comparable to the alternative (we could just drop and re-take the lock around the blk_finish_plug() rather than these two commits. I'd have preferred waiting for actual performance numbers before picking one approach over the other, but I don't want to release rc1 with the known "sleeping function called from invalid context" issue, so I'll pick this cleanup version for now. But if the numbers show that we really want to plug just at the writeback_sb_inodes() level, and we should just play ugly games with the spinlock, we'll switch to that. Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Neil Brown <neilb@suse.de> Cc: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index d8ea7ed411b2..587ac08eabb6 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1546,12 +1546,15 @@ static long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages,
.range_cyclic = 1,
.reason = reason,
+ struct blk_plug plug;
+ blk_start_plug(&plug);
if (list_empty(&wb->b_io))
queue_io(wb, &work);
__writeback_inodes_wb(wb, &work);
+ blk_finish_plug(&plug);
return nr_pages - work.nr_pages;
@@ -1579,10 +1582,12 @@ static long wb_writeback(struct bdi_writeback *wb,
unsigned long oldest_jif;
struct inode *inode;
long progress;
+ struct blk_plug plug;
oldest_jif = jiffies;
work->older_than_this = &oldest_jif;
+ blk_start_plug(&plug);
for (;;) {
@@ -1662,6 +1667,7 @@ static long wb_writeback(struct bdi_writeback *wb,
+ blk_finish_plug(&plug);
return nr_pages - work->nr_pages;

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