Message ID | 20130809150744.GB25306@dhcp-26-207.brq.redhat.com |
---|---|
State | Not Applicable |
Delegated to: | David Miller |
Headers | show |
On 08/09/2013 09:07 AM, Alexander Gordeev wrote: > On Fri, Aug 09, 2013 at 08:24:38AM -0600, Jens Axboe wrote: >> On 08/09/2013 02:23 AM, Alexander Gordeev wrote: >>> + ap->qc_tags = blk_mq_init_tags(ATA_MAX_QUEUE, 1, NUMA_NO_NODE); >>> + if (!ap->qc_tags) { >>> + kfree(ap); >>> + return NULL; >>> + } >> >> This should be blk_mq_init_tags(ATA_MAX_QUEUE - 1, 1, ...) since the >> total depth is normal_tags + reserved_tags. > > Aha.. If blk_mq_init_tags() should be like this then? > > diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c > index dcbc2a4..b131a48 100644 > --- a/block/blk-mq-tag.c > +++ b/block/blk-mq-tag.c > @@ -468,10 +468,9 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, > * Rest of the tags start at the queue list > */ > tags->nr_free = 0; > - while (nr_tags - tags->nr_reserved) { > + while (nr_tags--) { > tags->freelist[tags->nr_free] = tags->nr_free + > tags->nr_reserved; > - nr_tags--; > tags->nr_free++; > } I misremembered, just checked the code. I think I used to have it like I described, but changed it since I thought it would be more logical to pass in full depth, and then what part of that is reserved. Looking at the current code, your patch looks correct as-is.
On Fri, Aug 09, 2013 at 09:52:19AM -0600, Jens Axboe wrote: > On 08/09/2013 09:07 AM, Alexander Gordeev wrote: > > diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c > > index dcbc2a4..b131a48 100644 > > --- a/block/blk-mq-tag.c > > +++ b/block/blk-mq-tag.c > > @@ -468,10 +468,9 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, > > * Rest of the tags start at the queue list > > */ > > tags->nr_free = 0; > > - while (nr_tags - tags->nr_reserved) { > > + while (nr_tags--) { > > tags->freelist[tags->nr_free] = tags->nr_free + > > tags->nr_reserved; > > - nr_tags--; > > tags->nr_free++; > > } > > I misremembered, just checked the code. I think I used to have it like I > described, but changed it since I thought it would be more logical to > pass in full depth, and then what part of that is reserved. Looking at > the current code, your patch looks correct as-is. Ok, then a whole series "[PATCH 0/3] blk-mq: Avoid effects of a weird queue depth" (I posted earlier in a separate thread) should make sense. Besides the hunk above it limits the per-cpu cache size and sanity-checks total vs reserved length. I can resubmit if you want. > > -- > Jens Axboe >
On 08/09/2013 10:46 AM, Alexander Gordeev wrote: > On Fri, Aug 09, 2013 at 09:52:19AM -0600, Jens Axboe wrote: >> On 08/09/2013 09:07 AM, Alexander Gordeev wrote: >>> diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c >>> index dcbc2a4..b131a48 100644 >>> --- a/block/blk-mq-tag.c >>> +++ b/block/blk-mq-tag.c >>> @@ -468,10 +468,9 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, >>> * Rest of the tags start at the queue list >>> */ >>> tags->nr_free = 0; >>> - while (nr_tags - tags->nr_reserved) { >>> + while (nr_tags--) { >>> tags->freelist[tags->nr_free] = tags->nr_free + >>> tags->nr_reserved; >>> - nr_tags--; >>> tags->nr_free++; >>> } >> >> I misremembered, just checked the code. I think I used to have it like I >> described, but changed it since I thought it would be more logical to >> pass in full depth, and then what part of that is reserved. Looking at >> the current code, your patch looks correct as-is. > > Ok, then a whole series "[PATCH 0/3] blk-mq: Avoid effects of a weird queue > depth" (I posted earlier in a separate thread) should make sense. Besides > the hunk above it limits the per-cpu cache size and sanity-checks total vs > reserved length. I can resubmit if you want. You don't have to resubmit, I'll get it reviewed and applied today.
On Fri, Aug 09, 2013 at 11:07:37AM -0600, Jens Axboe wrote: > You don't have to resubmit, I'll get it reviewed and applied today. Hi Jens, I limited the minimal queue depth to 4, which is apparently wrong in case of libata. I will post a new series. > -- > Jens Axboe >
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index dcbc2a4..b131a48 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -468,10 +468,9 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, * Rest of the tags start at the queue list */ tags->nr_free = 0; - while (nr_tags - tags->nr_reserved) { + while (nr_tags--) { tags->freelist[tags->nr_free] = tags->nr_free + tags->nr_reserved; - nr_tags--; tags->nr_free++; }