From: Keith Busch <keith.busch@intel.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Linux Block <linux-block@vger.kernel.org>,
Linux NVMe <linux-nvme@lists.infradead.org>,
Device Mapper <dm-devel@redhat.com>,
Mike Snitzer <snitzer@redhat.com>, Jens Axboe <axboe@kernel.dk>,
Bart VanAssche <bart.vanassche@wdc.com>,
James Smart <james.smart@broadcom.com>,
"Martin K . Petersen" <martin.petersen@oracle.com>,
Hannes Reinecke <hare@suse.com>, Sagi Grimberg <sagi@grimberg.me>
Subject: Re: [PATCH 2/5] nvme/multipath: Consult blk_status_t for failover
Date: Tue, 9 Jan 2018 10:38:58 -0700 [thread overview]
Message-ID: <20180109173857.GF15154@localhost.localdomain> (raw)
In-Reply-To: <20180108095707.GD4673@lst.de>
On Mon, Jan 08, 2018 at 01:57:07AM -0800, Christoph Hellwig wrote:
> > - if (unlikely(nvme_req(req)->status && nvme_req_needs_retry(req))) {
> > - if (nvme_req_needs_failover(req)) {
> > + blk_status_t status = nvme_error_status(req);
> > +
> > + if (unlikely(status != BLK_STS_OK && nvme_req_needs_retry(req))) {
> > + if (nvme_req_needs_failover(req, status)) {
>
> We don't really need to call nvme_error_status if nvme_req(req)->status
> is zero.
We are already calling nvme_error_status unconditionally for
blk_mq_end_request, so we currently read nvme_req(req)->status multiple
times in the completion path. I think we'd prefer to read it just once.
WARNING: multiple messages have this Message-ID (diff)
From: keith.busch@intel.com (Keith Busch)
Subject: [PATCH 2/5] nvme/multipath: Consult blk_status_t for failover
Date: Tue, 9 Jan 2018 10:38:58 -0700 [thread overview]
Message-ID: <20180109173857.GF15154@localhost.localdomain> (raw)
In-Reply-To: <20180108095707.GD4673@lst.de>
On Mon, Jan 08, 2018@01:57:07AM -0800, Christoph Hellwig wrote:
> > - if (unlikely(nvme_req(req)->status && nvme_req_needs_retry(req))) {
> > - if (nvme_req_needs_failover(req)) {
> > + blk_status_t status = nvme_error_status(req);
> > +
> > + if (unlikely(status != BLK_STS_OK && nvme_req_needs_retry(req))) {
> > + if (nvme_req_needs_failover(req, status)) {
>
> We don't really need to call nvme_error_status if nvme_req(req)->status
> is zero.
We are already calling nvme_error_status unconditionally for
blk_mq_end_request, so we currently read nvme_req(req)->status multiple
times in the completion path. I think we'd prefer to read it just once.
next prev parent reply other threads:[~2018-01-09 17:38 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-04 22:46 [PATCH 0/5] Failover criteria unification Keith Busch
2018-01-04 22:46 ` Keith Busch
2018-01-04 22:46 ` [PATCH 1/5] nvme: Add more command status translation Keith Busch
2018-01-04 22:46 ` Keith Busch
2018-01-04 23:41 ` Mike Snitzer
2018-01-04 23:41 ` Mike Snitzer
2018-01-08 8:39 ` Hannes Reinecke
2018-01-08 8:39 ` Hannes Reinecke
2018-01-08 9:55 ` Christoph Hellwig
2018-01-08 9:55 ` Christoph Hellwig
2018-01-08 10:09 ` Hannes Reinecke
2018-01-08 10:09 ` Hannes Reinecke
2018-01-08 10:19 ` Christoph Hellwig
2018-01-08 10:19 ` Christoph Hellwig
2018-01-08 15:29 ` Mike Snitzer
2018-01-08 15:29 ` Mike Snitzer
2018-01-08 15:34 ` Christoph Hellwig
2018-01-08 15:34 ` Christoph Hellwig
2018-01-08 16:12 ` Keith Busch
2018-01-08 16:12 ` Keith Busch
2018-01-04 22:46 ` [PATCH 2/5] nvme/multipath: Consult blk_status_t for failover Keith Busch
2018-01-04 22:46 ` Keith Busch
2018-01-04 23:42 ` Mike Snitzer
2018-01-04 23:42 ` Mike Snitzer
2018-01-08 8:57 ` Hannes Reinecke
2018-01-08 8:57 ` Hannes Reinecke
2018-01-08 9:57 ` Christoph Hellwig
2018-01-08 9:57 ` Christoph Hellwig
2018-01-09 17:38 ` Keith Busch [this message]
2018-01-09 17:38 ` Keith Busch
2018-01-09 17:40 ` Christoph Hellwig
2018-01-09 17:40 ` Christoph Hellwig
2018-01-04 22:46 ` [PATCH 3/5] block: Provide blk_status_t decoding for retryable errors Keith Busch
2018-01-04 22:46 ` Keith Busch
2018-01-04 23:43 ` Mike Snitzer
2018-01-04 23:43 ` Mike Snitzer
2018-01-08 8:58 ` Hannes Reinecke
2018-01-08 8:58 ` Hannes Reinecke
2018-01-08 9:58 ` Christoph Hellwig
2018-01-08 9:58 ` Christoph Hellwig
2018-01-04 22:46 ` [PATCH 4/5] nvme/multipath: Use blk_retryable Keith Busch
2018-01-04 22:46 ` Keith Busch
2018-01-04 23:44 ` Mike Snitzer
2018-01-04 23:44 ` Mike Snitzer
2018-01-08 8:58 ` Hannes Reinecke
2018-01-08 8:58 ` Hannes Reinecke
2018-01-04 22:46 ` [PATCH 5/5] dm mpath: " Keith Busch
2018-01-04 22:46 ` Keith Busch
2018-01-04 23:45 ` Mike Snitzer
2018-01-04 23:45 ` Mike Snitzer
2018-01-08 8:59 ` Hannes Reinecke
2018-01-08 8:59 ` Hannes Reinecke
2018-01-04 23:36 ` [PATCH 0/5] Failover criteria unification Mike Snitzer
2018-01-04 23:36 ` Mike Snitzer
2018-01-04 23:47 ` Keith Busch
2018-01-04 23:47 ` Keith Busch
2018-01-05 0:07 ` Mike Snitzer
2018-01-05 0:07 ` Mike Snitzer
2018-01-08 9:58 ` Christoph Hellwig
2018-01-08 9:58 ` Christoph Hellwig
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