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| author |   tang.junhui <tang.junhui@zte.com.cn> | 2017-10-30 14:46:34 -0700 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2017-10-30 15:57:54 -0600 |
| commit | c157313791a999646901b3e3c6888514ebc36d62 (patch) | |
| tree | 8b5fef73f04ef261fcc6761950795ebd3db9cc5c /drivers/md/bcache/request.c | |
| parent | bcache: update bucket_in_use in real time (diff) | |
| download | linux-dev-c157313791a999646901b3e3c6888514ebc36d62.tar.xz linux-dev-c157313791a999646901b3e3c6888514ebc36d62.zip | |
bcache: fix wrong cache_misses statistics
Currently, Cache missed IOs are identified by s->cache_miss, but actually,
there are many situations that missed IOs are not assigned a value for
s->cache_miss in cached_dev_cache_miss(), for example, a bypassed IO
(s->iop.bypass = 1), or the cache_bio allocate failed. In these situations,
it will go to out_put or out_submit, and s->cache_miss is null, which leads
bch_mark_cache_accounting() to treat this IO as a hit IO.
[ML: applied by 3-way merge]
Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md/bcache/request.c')
| -rw-r--r-- | drivers/md/bcache/request.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index 886e4b6643f1..597dd1e87bea 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -470,6 +470,7 @@ struct search { unsigned recoverable:1; unsigned write:1; unsigned read_dirty_data:1; + unsigned cache_missed:1; unsigned long start_time; @@ -656,6 +657,7 @@ static inline struct search *search_alloc(struct bio *bio, s->orig_bio = bio; s->cache_miss = NULL; + s->cache_missed = 0; s->d = d; s->recoverable = 1; s->write = op_is_write(bio_op(bio)); @@ -775,7 +777,7 @@ static void cached_dev_read_done_bh(struct closure *cl) struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); bch_mark_cache_accounting(s->iop.c, s->d, - !s->cache_miss, s->iop.bypass); + !s->cache_missed, s->iop.bypass); trace_bcache_read(s->orig_bio, !s->cache_miss, s->iop.bypass); if (s->iop.status) @@ -794,6 +796,8 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s, struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); struct bio *miss, *cache_bio; + s->cache_missed = 1; + if (s->cache_miss || s->iop.bypass) { miss = bio_next_split(bio, sectors, GFP_NOIO, s->d->bio_split); ret = miss == bio ? MAP_DONE : MAP_CONTINUE; |