From: Bart Van Assche <Bart.VanAssche@wdc.com>
To: "ming.lei@redhat.com" <ming.lei@redhat.com>
Cc: "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"hch@infradead.org" <hch@infradead.org>,
"sagi@grimberg.me" <sagi@grimberg.me>,
"snitzer@redhat.com" <snitzer@redhat.com>,
"martin.petersen@oracle.com" <martin.petersen@oracle.com>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"axboe@fb.com" <axboe@fb.com>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
"jejb@linux.vnet.ibm.com" <jejb@linux.vnet.ibm.com>,
"loberman@redhat.com" <loberman@redhat.com>,
"dm-devel@redhat.com" <dm-devel@redhat.com>
Subject: Re: [PATCH 1/5] block: don't call blk_mq_delay_run_hw_queue() in case of BLK_STS_RESOURCE
Date: Tue, 19 Sep 2017 15:36:35 +0000 [thread overview]
Message-ID: <1505835394.2671.18.camel@wdc.com> (raw)
In-Reply-To: <20170919054308.GA2517@ming.t460p>
On Tue, 2017-09-19 at 13:43 +0800, Ming Lei wrote:
> On Mon, Sep 18, 2017 at 03:18:16PM +0000, Bart Van Assche wrote:
> > If you are still looking at removing the blk_mq_delay_run_hw_queue() calls
> > then I think you are looking in the wrong direction. What kind of problem
> > are you trying to solve? Is it perhaps that there can be a delay between
>
> Actually the improvement on dm-rq IO schedule(the patch 2 ~ 5) doesn't
> need this patch.
The approach of this patch series looks wrong to me and patch 5/5 is an ugly
hack in my opinion. That's why I asked you to drop the entire patch series and
to test whether inserting a queue run call into the dm-mpath end_io callback
yields a similar performance improvement to the patches you posted. Please do
not expect me to spend more time on this patch series if you do not come up
with measurement results for the proposed alternative.
Bart.
WARNING: multiple messages have this Message-ID (diff)
From: Bart Van Assche <Bart.VanAssche@wdc.com>
To: "ming.lei@redhat.com" <ming.lei@redhat.com>
Cc: "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"hch@infradead.org" <hch@infradead.org>,
"sagi@grimberg.me" <sagi@grimberg.me>,
"snitzer@redhat.com" <snitzer@redhat.com>,
"martin.petersen@oracle.com" <martin.petersen@oracle.com>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"axboe@fb.com" <axboe@fb.com>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
"jejb@linux.vnet.ibm.com" <jejb@linux.vnet.ibm.com>,
"loberman@redhat.com" <loberman@redhat.com>,
"dm-devel@redhat.com" <dm-devel@redhat.com>
Subject: Re: [PATCH 1/5] block: don't call blk_mq_delay_run_hw_queue() in case of BLK_STS_RESOURCE
Date: Tue, 19 Sep 2017 15:36:35 +0000 [thread overview]
Message-ID: <1505835394.2671.18.camel@wdc.com> (raw)
In-Reply-To: <20170919054308.GA2517@ming.t460p>
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WARNING: multiple messages have this Message-ID (diff)
From: Bart.VanAssche@wdc.com (Bart Van Assche)
Subject: [PATCH 1/5] block: don't call blk_mq_delay_run_hw_queue() in case of BLK_STS_RESOURCE
Date: Tue, 19 Sep 2017 15:36:35 +0000 [thread overview]
Message-ID: <1505835394.2671.18.camel@wdc.com> (raw)
In-Reply-To: <20170919054308.GA2517@ming.t460p>
On Tue, 2017-09-19@13:43 +0800, Ming Lei wrote:
> On Mon, Sep 18, 2017@03:18:16PM +0000, Bart Van Assche wrote:
> > If you are still looking at removing the blk_mq_delay_run_hw_queue() calls
> > then I think you are looking in the wrong direction. What kind of problem
> > are you trying to solve? Is it perhaps that there can be a delay between
>
> Actually the improvement on dm-rq IO schedule(the patch 2 ~ 5) doesn't
> need this patch.
The approach of this patch series looks wrong to me and patch 5/5 is an ugly
hack in my opinion. That's why I asked you to drop the entire patch series and
to test whether inserting a queue run call into the dm-mpath end_io callback
yields a similar performance improvement to the patches you posted. Please do
not expect me to spend more time on this patch series if you do not come up
with measurement results for the proposed alternative.
Bart.
next prev parent reply other threads:[~2017-09-19 15:36 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-15 16:44 [PATCH 0/5] dm-mpath: improve I/O schedule Ming Lei
2017-09-15 16:44 ` Ming Lei
2017-09-15 16:44 ` [PATCH 1/5] block: don't call blk_mq_delay_run_hw_queue() in case of BLK_STS_RESOURCE Ming Lei
2017-09-15 16:44 ` Ming Lei
2017-09-15 17:57 ` Bart Van Assche
2017-09-15 17:57 ` Bart Van Assche
2017-09-15 17:57 ` Bart Van Assche
2017-09-17 12:40 ` Ming Lei
2017-09-17 12:40 ` Ming Lei
2017-09-18 15:18 ` Bart Van Assche
2017-09-18 15:18 ` Bart Van Assche
2017-09-18 15:18 ` Bart Van Assche
2017-09-19 5:43 ` Ming Lei
2017-09-19 5:43 ` Ming Lei
2017-09-19 15:36 ` Bart Van Assche [this message]
2017-09-19 15:36 ` Bart Van Assche
2017-09-19 15:36 ` Bart Van Assche
2017-09-19 15:56 ` Mike Snitzer
2017-09-19 15:56 ` Mike Snitzer
2017-09-19 16:04 ` Ming Lei
2017-09-19 16:04 ` Ming Lei
2017-09-19 16:49 ` Bart Van Assche
2017-09-19 16:49 ` Bart Van Assche
2017-09-19 16:49 ` Bart Van Assche
2017-09-19 16:55 ` Ming Lei
2017-09-19 16:55 ` Ming Lei
2017-09-19 18:42 ` Bart Van Assche
2017-09-19 18:42 ` Bart Van Assche
2017-09-19 18:42 ` Bart Van Assche
2017-09-19 22:44 ` Ming Lei
2017-09-19 22:44 ` Ming Lei
2017-09-19 23:25 ` Bart Van Assche
2017-09-19 23:25 ` Bart Van Assche
2017-09-19 23:25 ` Bart Van Assche
2017-09-19 23:50 ` Mike Snitzer
2017-09-19 23:50 ` Mike Snitzer
2017-09-20 1:13 ` Ming Lei
2017-09-20 1:13 ` Ming Lei
2017-09-20 1:19 ` Ming Lei
2017-09-20 1:19 ` Ming Lei
2017-09-19 15:48 ` Mike Snitzer
2017-09-19 15:48 ` Mike Snitzer
2017-09-19 15:52 ` Bart Van Assche
2017-09-19 15:52 ` Bart Van Assche
2017-09-19 15:52 ` Bart Van Assche
2017-09-19 16:03 ` Mike Snitzer
2017-09-19 16:03 ` Mike Snitzer
2017-09-19 16:07 ` Ming Lei
2017-09-19 16:07 ` Ming Lei
2017-09-15 16:44 ` [PATCH 2/5] dm-mpath: return DM_MAPIO_REQUEUE in case of rq allocation failure Ming Lei
2017-09-15 17:29 ` Bart Van Assche
2017-09-15 17:29 ` Bart Van Assche
2017-09-15 20:06 ` Mike Snitzer
2017-09-15 20:48 ` Bart Van Assche
2017-09-15 20:48 ` Bart Van Assche
2017-09-17 13:23 ` Ming Lei
2017-09-19 14:41 ` Mike Snitzer
2017-09-19 15:56 ` Ming Lei
2017-09-17 12:51 ` Ming Lei
2017-09-15 16:44 ` [PATCH 3/5] dm-mpath: remove annoying message of 'blk_get_request() returned -11' Ming Lei
2017-09-15 16:44 ` [PATCH 4/5] block: export blk_update_nr_requests Ming Lei
2017-09-15 16:44 ` [PATCH 5/5] dm-mpath: improve I/O schedule Ming Lei
2017-09-15 20:10 ` Mike Snitzer
2017-09-15 20:56 ` Bart Van Assche
2017-09-15 20:56 ` Bart Van Assche
2017-09-15 21:06 ` Bart Van Assche
2017-09-15 21:06 ` Bart Van Assche
2017-09-15 21:42 ` Bart Van Assche
2017-09-15 21:42 ` Bart Van Assche
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