From: Christoph Hellwig <hch@lst.de>
To: Alexander Gordeev <agordeev@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>,
tglx@linutronix.de, axboe@fb.com, linux-block@vger.kernel.org,
linux-pci@vger.kernel.org, linux-nvme@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 11/13] blk-mq: allow the driver to pass in an affinity mask
Date: Mon, 4 Jul 2016 10:38:49 +0200 [thread overview]
Message-ID: <20160704083849.GA3585@lst.de> (raw)
In-Reply-To: <20160704081540.GA2783@agordeev.lab.eng.brq.redhat.com>
On Mon, Jul 04, 2016 at 10:15:41AM +0200, Alexander Gordeev wrote:
> On Tue, Jun 14, 2016 at 09:59:04PM +0200, Christoph Hellwig wrote:
> > +static int blk_mq_create_mq_map(struct blk_mq_tag_set *set,
> > + const struct cpumask *affinity_mask)
> > +{
> > + int queue = -1, cpu = 0;
> > +
> > + set->mq_map = kzalloc_node(sizeof(*set->mq_map) * nr_cpu_ids,
> > + GFP_KERNEL, set->numa_node);
> > + if (!set->mq_map)
> > + return -ENOMEM;
> > +
> > + if (!affinity_mask)
> > + return 0; /* map all cpus to queue 0 */
> > +
> > + /* If cpus are offline, map them to first hctx */
> > + for_each_online_cpu(cpu) {
> > + if (cpumask_test_cpu(cpu, affinity_mask))
> > + queue++;
>
> CPUs missing in an affinity mask are mapped to hctxs. Is that intended?
Yes - each CPU needs to be mapped to some hctx, otherwise we can't
submit I/O from that CPU.
> > + if (queue > 0)
>
> Why this check?
>
> > + set->mq_map[cpu] = queue;
mq_map is initialized to zero already, so we don't really need the
assignment for queue 0. The reason why this check exists is because
we start with queue = -1 and we never want to assignment -1 to mq_map.
WARNING: multiple messages have this Message-ID (diff)
From: hch@lst.de (Christoph Hellwig)
Subject: [PATCH 11/13] blk-mq: allow the driver to pass in an affinity mask
Date: Mon, 4 Jul 2016 10:38:49 +0200 [thread overview]
Message-ID: <20160704083849.GA3585@lst.de> (raw)
In-Reply-To: <20160704081540.GA2783@agordeev.lab.eng.brq.redhat.com>
On Mon, Jul 04, 2016@10:15:41AM +0200, Alexander Gordeev wrote:
> On Tue, Jun 14, 2016@09:59:04PM +0200, Christoph Hellwig wrote:
> > +static int blk_mq_create_mq_map(struct blk_mq_tag_set *set,
> > + const struct cpumask *affinity_mask)
> > +{
> > + int queue = -1, cpu = 0;
> > +
> > + set->mq_map = kzalloc_node(sizeof(*set->mq_map) * nr_cpu_ids,
> > + GFP_KERNEL, set->numa_node);
> > + if (!set->mq_map)
> > + return -ENOMEM;
> > +
> > + if (!affinity_mask)
> > + return 0; /* map all cpus to queue 0 */
> > +
> > + /* If cpus are offline, map them to first hctx */
> > + for_each_online_cpu(cpu) {
> > + if (cpumask_test_cpu(cpu, affinity_mask))
> > + queue++;
>
> CPUs missing in an affinity mask are mapped to hctxs. Is that intended?
Yes - each CPU needs to be mapped to some hctx, otherwise we can't
submit I/O from that CPU.
> > + if (queue > 0)
>
> Why this check?
>
> > + set->mq_map[cpu] = queue;
mq_map is initialized to zero already, so we don't really need the
assignment for queue 0. The reason why this check exists is because
we start with queue = -1 and we never want to assignment -1 to mq_map.
next prev parent reply other threads:[~2016-07-04 8:38 UTC|newest]
Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-14 19:58 automatic interrupt affinity for MSI/MSI-X capable devices V2 Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 19:58 ` [PATCH 01/13] irq/msi: Remove unused MSI_FLAG_IDENTITY_MAP Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-16 9:05 ` Bart Van Assche
2016-06-16 9:05 ` Bart Van Assche
2016-06-14 19:58 ` [PATCH 02/13] irq: Introduce IRQD_AFFINITY_MANAGED flag Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-15 8:44 ` Bart Van Assche
2016-06-15 8:44 ` Bart Van Assche
2016-06-15 10:23 ` Christoph Hellwig
2016-06-15 10:23 ` Christoph Hellwig
2016-06-15 10:42 ` Bart Van Assche
2016-06-15 10:42 ` Bart Van Assche
2016-06-15 10:42 ` Bart Van Assche
2016-06-15 15:14 ` Keith Busch
2016-06-15 15:14 ` Keith Busch
2016-06-15 15:28 ` Bart Van Assche
2016-06-15 15:28 ` Bart Van Assche
2016-06-15 16:03 ` Keith Busch
2016-06-15 16:03 ` Keith Busch
2016-06-15 19:36 ` Bart Van Assche
2016-06-15 19:36 ` Bart Van Assche
2016-06-15 20:06 ` Keith Busch
2016-06-15 20:06 ` Keith Busch
2016-06-15 20:12 ` Keith Busch
2016-06-15 20:12 ` Keith Busch
2016-06-15 20:50 ` Bart Van Assche
2016-06-15 20:50 ` Bart Van Assche
2016-06-16 15:19 ` Keith Busch
2016-06-16 15:19 ` Keith Busch
2016-06-22 11:56 ` Alexander Gordeev
2016-06-22 11:56 ` Alexander Gordeev
2016-06-22 11:56 ` Alexander Gordeev
2016-06-16 15:20 ` Christoph Hellwig
2016-06-16 15:20 ` Christoph Hellwig
2016-06-16 15:39 ` Bart Van Assche
2016-06-16 15:39 ` Bart Van Assche
2016-06-20 12:22 ` Christoph Hellwig
2016-06-20 12:22 ` Christoph Hellwig
2016-06-20 12:22 ` Christoph Hellwig
2016-06-20 13:21 ` Bart Van Assche
2016-06-20 13:21 ` Bart Van Assche
2016-06-20 13:21 ` Bart Van Assche
2016-06-21 14:31 ` Christoph Hellwig
2016-06-21 14:31 ` Christoph Hellwig
2016-06-21 14:31 ` Christoph Hellwig
2016-06-16 9:08 ` Bart Van Assche
2016-06-16 9:08 ` Bart Van Assche
2016-06-14 19:58 ` [PATCH 03/13] irq: Add affinity hint to irq allocation Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 19:58 ` [PATCH 04/13] irq: Use affinity hint in irqdesc allocation Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 19:58 ` [PATCH 05/13] irq/msi: Make use of affinity aware allocations Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 19:58 ` [PATCH 06/13] irq: add a helper spread an affinity mask for MSI/MSI-X vectors Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 19:58 ` Christoph Hellwig
2016-06-14 21:54 ` Guilherme G. Piccoli
2016-06-14 21:54 ` Guilherme G. Piccoli
2016-06-15 8:35 ` Bart Van Assche
2016-06-15 8:35 ` Bart Van Assche
2016-06-15 8:35 ` Bart Van Assche
2016-06-15 10:10 ` Christoph Hellwig
2016-06-15 10:10 ` Christoph Hellwig
2016-06-15 13:09 ` Guilherme G. Piccoli
2016-06-15 13:09 ` Guilherme G. Piccoli
2016-06-16 15:16 ` Christoph Hellwig
2016-06-16 15:16 ` Christoph Hellwig
2016-06-25 20:05 ` Alexander Gordeev
2016-06-25 20:05 ` Alexander Gordeev
2016-06-30 17:48 ` Christoph Hellwig
2016-06-30 17:48 ` Christoph Hellwig
2016-06-30 17:48 ` Christoph Hellwig
2016-07-01 7:25 ` Alexander Gordeev
2016-07-01 7:25 ` Alexander Gordeev
2016-06-14 19:59 ` [PATCH 07/13] pci: Provide sensible irq vector alloc/free routines Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-23 11:16 ` Alexander Gordeev
2016-06-23 11:16 ` Alexander Gordeev
2016-06-30 16:54 ` Christoph Hellwig
2016-06-30 16:54 ` Christoph Hellwig
2016-06-30 17:28 ` Alexander Gordeev
2016-06-30 17:28 ` Alexander Gordeev
2016-06-30 17:35 ` Christoph Hellwig
2016-06-30 17:35 ` Christoph Hellwig
2016-06-14 19:59 ` [PATCH 08/13] pci: spread interrupt vectors in pci_alloc_irq_vectors Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-25 20:22 ` Alexander Gordeev
2016-06-25 20:22 ` Alexander Gordeev
2016-06-14 19:59 ` [PATCH 09/13] blk-mq: don't redistribute hardware queues on a CPU hotplug event Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-14 19:59 ` [PATCH 10/13] blk-mq: only allocate a single mq_map per tag_set Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-14 19:59 ` [PATCH 11/13] blk-mq: allow the driver to pass in an affinity mask Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-07-04 8:15 ` Alexander Gordeev
2016-07-04 8:15 ` Alexander Gordeev
2016-07-04 8:38 ` Christoph Hellwig [this message]
2016-07-04 8:38 ` Christoph Hellwig
2016-07-04 9:35 ` Alexander Gordeev
2016-07-04 9:35 ` Alexander Gordeev
2016-07-10 3:41 ` Christoph Hellwig
2016-07-10 3:41 ` Christoph Hellwig
2016-07-12 6:42 ` Alexander Gordeev
2016-07-12 6:42 ` Alexander Gordeev
2016-06-14 19:59 ` [PATCH 12/13] nvme: switch to use pci_alloc_irq_vectors Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-14 19:59 ` [PATCH 13/13] nvme: remove the post_scan callout Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-14 19:59 ` Christoph Hellwig
2016-06-16 9:45 ` automatic interrupt affinity for MSI/MSI-X capable devices V2 Bart Van Assche
2016-06-16 9:45 ` Bart Van Assche
2016-06-16 9:45 ` Bart Van Assche
2016-06-16 15:22 ` Christoph Hellwig
2016-06-16 15:22 ` Christoph Hellwig
2016-06-26 19:40 ` Alexander Gordeev
2016-06-26 19:40 ` Alexander Gordeev
2016-07-04 8:39 automatic interrupt affinity for MSI/MSI-X capable devices V3 Christoph Hellwig
2016-07-04 8:39 ` [PATCH 11/13] blk-mq: allow the driver to pass in an affinity mask Christoph Hellwig
2016-07-04 8:39 ` Christoph Hellwig
2016-07-04 8:39 ` Christoph Hellwig
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