diff options
| author | Coly Li <colyli@suse.de> | 2019-06-28 19:59:24 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-06-28 07:39:13 -0600 |
| commit | 141df8bb5dc052f605de8f48a7aa10290e1384ae (patch) | |
| tree | 355b2bb99b0584a0f09c00304e4e5b2252f5bb9f | |
| parent | a5b47a40bed8b19e956872fb55097d676a68f59e (diff) | |
bcache: don't set max writeback rate if gc is running
When gc is running, user space I/O processes may wait inside
bcache code, so no new I/O coming. Indeed this is not a real idle
time, maximum writeback rate should not be set in such situation.
Otherwise a faster writeback thread may compete locks with gc thread
and makes garbage collection slower, which results a longer I/O
freeze period.
This patch checks c->gc_mark_valid in set_at_max_writeback_rate(). If
c->gc_mark_valid is 0 (gc running), set_at_max_writeback_rate() returns
false, then update_writeback_rate() will not set writeback rate to
maximum value even c->idle_counter reaches an idle threshold.
Now writeback thread won't interfere gc thread performance.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | drivers/md/bcache/writeback.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c index 73f0efac2b9f..262f7ef20992 100644 --- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c @@ -122,6 +122,9 @@ static void __update_writeback_rate(struct cached_dev *dc) static bool set_at_max_writeback_rate(struct cache_set *c, struct cached_dev *dc) { + /* Don't set max writeback rate if gc is running */ + if (!c->gc_mark_valid) + return false; /* * Idle_counter is increased everytime when update_writeback_rate() is * called. If all backing devices attached to the same cache set have |