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| author | Coly Li <colyli@suse.de> | 2018-12-13 17:53:53 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-12-13 18:15:54 +0300 |
| commit | 7a671d8ef821bf5743fdff17fae0600648345b03 (patch) | |
| tree | a4199a4a11b9fff8b6e02d7e6dad331991c091a9 /drivers/md/bcache/writeback.h | |
| parent | cb07ad63682ffcce10e9beaed7828a26780e3df9 (diff) | |
| download | linux-7a671d8ef821bf5743fdff17fae0600648345b03.tar.xz | |
bcache: option to automatically run gc thread after writeback
The option gc_after_writeback is disabled by default, because garbage
collection will discard SSD data which drops cached data.
Echo 1 into /sys/fs/bcache/<UUID>/internal/gc_after_writeback will
enable this option, which wakes up gc thread when writeback accomplished
and all cached data is clean.
This option is helpful for people who cares writing performance more. In
heavy writing workload, all cached data can be clean only happens when
writeback thread cleans all cached data in I/O idle time. In such
situation a following gc running may help to shrink bcache B+ tree and
discard more clean data, which may be helpful for future writing
requests.
If you are not sure whether this is helpful for your own workload,
please leave it as disabled by default.
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md/bcache/writeback.h')
| -rw-r--r-- | drivers/md/bcache/writeback.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h index d2b9fdbc8994..ce63be98a39d 100644 --- a/drivers/md/bcache/writeback.h +++ b/drivers/md/bcache/writeback.h @@ -11,6 +11,8 @@ #define WRITEBACK_RATE_UPDATE_SECS_MAX 60 #define WRITEBACK_RATE_UPDATE_SECS_DEFAULT 5 +#define BCH_AUTO_GC_DIRTY_THRESHOLD 50 + /* * 14 (16384ths) is chosen here as something that each backing device * should be a reasonable fraction of the share, and not to blow up |