| Message ID | 1509158391-31992-1-git-send-email-tang.junhui@zte.com.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2017/10/28 上午10:39, tang.junhui@zte.com.cn wrote: > From: "tang.junhui" <tang.junhui@zte.com.cn> > > 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. > > Signed-off-by: tang.junhui <tang.junhui@zte.com.cn> It is good to me, thanks. Reviewed-by: Coly Li <colyli@suse.de> Coly Li > --- > drivers/md/bcache/request.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c > index 76d2087..8f280e9 100644 > --- a/drivers/md/bcache/request.c > +++ b/drivers/md/bcache/request.c > @@ -468,6 +468,7 @@ struct search { > unsigned recoverable:1; > unsigned write:1; > unsigned read_dirty_data:1; > + unsigned cache_missed:1; > > unsigned long start_time; > > @@ -653,6 +654,7 @@ 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)); > @@ -764,7 +766,7 @@ 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.error) > @@ -783,6 +785,8 @@ 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; >
On 10/27/2017 07:39 PM, tang.junhui@zte.com.cn wrote: > From: "tang.junhui" <tang.junhui@zte.com.cn> > > 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. > > Signed-off-by: tang.junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Applied to my local tree for test. Thanks! -mpl
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index 76d2087..8f280e9 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -468,6 +468,7 @@ struct search { unsigned recoverable:1; unsigned write:1; unsigned read_dirty_data:1; + unsigned cache_missed:1; unsigned long start_time; @@ -653,6 +654,7 @@ 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)); @@ -764,7 +766,7 @@ 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.error) @@ -783,6 +785,8 @@ 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;