From mboxrd@z Thu Jan  1 00:00:00 1970
From: jthumshirn@suse.de (Johannes Thumshirn)
Date: Wed, 18 Jan 2017 16:16:43 +0100
Subject: [LSF/MM TOPIC][LSF/MM ATTEND] NAPI polling for block drivers
In-Reply-To: <c7eabe1c-5dcd-9859-2b41-9683f68a0534@grimberg.me>
References: <d60d4499-6ed8-0a69-edbf-db205a6dba6a@kernel.dk>
 <8b47ca34-d2ff-26dc-721e-2cb1e18f1efc@grimberg.me>
 <499af528-7810-f82d-1f11-cbf8f3a5b21c@grimberg.me>
 <53a3fb6c-c75a-519a-f669-2bcab404e01d@grimberg.me>
 <20170117162752.GE6067@linux-x5ow.site>
 <6df6bf6a-7cd3-1700-2b0a-e140325ebf47@grimberg.me>
 <20170118135156.GG3514@linux-x5ow.site>
 <e3438024-e0f2-db96-5122-4508863be603@grimberg.me>
 <20170118145816.GI3514@linux-x5ow.site>
 <c7eabe1c-5dcd-9859-2b41-9683f68a0534@grimberg.me>
Message-ID: <20170118151643.GJ3514@linux-x5ow.site>

On Wed, Jan 18, 2017@05:14:36PM +0200, Sagi Grimberg wrote:
> 
> >Hannes just spotted this:
> >static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
> >                         const struct blk_mq_queue_data *bd)
> >{
> >[...]
> >        __nvme_submit_cmd(nvmeq, &cmnd);
> >        nvme_process_cq(nvmeq);
> >        spin_unlock_irq(&nvmeq->q_lock);
> >        return BLK_MQ_RQ_QUEUE_OK;
> >out_cleanup_iod:
> >        nvme_free_iod(dev, req);
> >out_free_cmd:
> >        nvme_cleanup_cmd(req);
> >        return ret;
> >}
> >
> >So we're draining the CQ on submit. This of cause makes polling for
> >completions in the IRQ handler rather pointless as we already did in the
> >submission path.
> 
> I think you missed:
> http://git.infradead.org/nvme.git/commit/49c91e3e09dc3c9dd1718df85112a8cce3ab7007

I indeed did, thanks.

-- 
Johannes Thumshirn                                          Storage
jthumshirn at suse.de                                +49 911 74053 689
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