| Message ID | 1498855388-16990-4-git-send-email-bcache@lists.ewheeler.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2017/7/1 上午4:42, bcache@lists.ewheeler.net wrote: > From: Tang Junhui <tang.junhui@zte.com.cn> > > Some missed IOs are not counted into cache_misses, this patch fix this > issue. Could you please explain more about, - which kind of missed I/O are mot counted - where cache_missed is located This will help the patch to be more understandable. > > Signed-off-by: tang.junhui <tang.junhui@zte.com.cn> > Reviewed-by: Eric Wheeler <bcache@linux.ewheeler.net> > Cc: stable@vger.kernel.org [snip] > @@ -758,7 +760,7 @@ 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); Should the above line be changed to, trace_bcache_read(s->orig_bio, !s->cache_missed, s->iop.bypass); as well ? [snip] Thanks.
On Sun, 2 Jul 2017, Coly Li wrote: > On 2017/7/1 上午4:42, bcache@lists.ewheeler.net wrote: > > From: Tang Junhui <tang.junhui@zte.com.cn> > > > > Some missed IOs are not counted into cache_misses, this patch fix this > > issue. > > Could you please explain more about, > - which kind of missed I/O are mot counted > - where cache_missed is located > > This will help the patch to be more understandable. Hi Tang, I'm waiting to queue this patch pending your response to Coly. Can you update the message send a v2? -- Eric Wheeler > > > > > Signed-off-by: tang.junhui <tang.junhui@zte.com.cn> > > Reviewed-by: Eric Wheeler <bcache@linux.ewheeler.net> > > Cc: stable@vger.kernel.org > > [snip] > > > @@ -758,7 +760,7 @@ 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); > > > Should the above line be changed to, > trace_bcache_read(s->orig_bio, !s->cache_missed, s->iop.bypass); > as well ? > > > [snip] > > Thanks. > > -- > Coly Li >
On Thu, 13 Jul 2017, Eric Wheeler wrote: > On Sun, 2 Jul 2017, Coly Li wrote: > > > On 2017/7/1 上午4:42, bcache@lists.ewheeler.net wrote: > > > From: Tang Junhui <tang.junhui@zte.com.cn> > > > > > > Some missed IOs are not counted into cache_misses, this patch fix this > > > issue. > > > > Could you please explain more about, > > - which kind of missed I/O are mot counted > > - where cache_missed is located > > > > This will help the patch to be more understandable. > > Hi Tang, > > I'm waiting to queue this patch pending your response to Coly. Can you > update the message send a v2? Hi Tang, Can you to an update message and send this in so we can get the cache miss metrics corrected? -- Eric Wheeler > > > > > > > > > > > Signed-off-by: tang.junhui <tang.junhui@zte.com.cn> > > > Reviewed-by: Eric Wheeler <bcache@linux.ewheeler.net> > > > Cc: stable@vger.kernel.org > > > > [snip] > > > > > @@ -758,7 +760,7 @@ 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); > > > > > > Should the above line be changed to, > > trace_bcache_read(s->orig_bio, !s->cache_missed, s->iop.bypass); > > as well ? > > > > > > [snip] > > > > Thanks. > > > > -- > > Coly Li > >
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index 4b413db..d27707d 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -462,6 +462,7 @@ struct search { unsigned recoverable:1; unsigned write:1; unsigned read_dirty_data:1; + unsigned cache_missed:1; unsigned long start_time; @@ -647,6 +648,7 @@ 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)); @@ -758,7 +760,7 @@ 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) @@ -777,6 +779,8 @@ 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; /* true */ + 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;