From: Ming Lei <ming.lei@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>,
Bjorn Helgaas <helgaas@kernel.org>, Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, Sagi Grimberg <sagi@grimberg.me>,
linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org
Subject: Re: [PATCH 4/5] nvme-pci: simplify nvme_setup_irqs() via .setup_affinity callback
Date: Mon, 11 Feb 2019 12:09:12 +0800 [thread overview]
Message-ID: <20190211040911.GC8638@ming.t460p> (raw)
In-Reply-To: <alpine.DEB.2.21.1902101815260.8784@nanos.tec.linutronix.de>
On Sun, Feb 10, 2019 at 07:49:12PM +0100, Thomas Gleixner wrote:
> On Fri, 25 Jan 2019, Ming Lei wrote:
> > +static int nvme_setup_affinity(const struct irq_affinity *affd,
> > + struct irq_affinity_desc *masks,
> > + unsigned int nmasks)
> > +{
> > + struct nvme_dev *dev = affd->priv;
> > + int affvecs = nmasks - affd->pre_vectors - affd->post_vectors;
> > + int curvec, usedvecs;
> > + int i;
> > +
> > + nvme_calc_io_queues(dev, nmasks);
>
> So this is the only NVME specific information. Everything else can be done
> in generic code. So what you really want is:
>
> struct affd {
> ...
> + calc_sets(struct affd *, unsigned int nvecs);
> ...
> }
>
> And sets want to be actually inside of the affinity descriptor structure:
>
> unsigned int num_sets;
> unsigned int set_vectors[MAX_SETS];
>
> We surely can define a sensible maximum of sets for now. If that ever turns
> out to be insufficient, then struct affd might become to large for the
> stack, but for now, using e.g. 8, there is no need to do so.
>
> So then the logic in the generic code becomes exactly the same as what you
> added to nvme_setup_affinity():
>
> if (affd->calc_sets) {
> affd->calc_sets(affd, nvecs);
> } else if (!affd->num_sets) {
> affd->num_sets = 1;
> affd->set_vectors[0] = affvecs;
> }
>
> for (i = 0; i < affd->num_sets; i++) {
> ....
> }
>
> See?
OK, will do this way in V2, then we can avoid drivers to abuse
the callback.
Thanks,
Ming
next prev parent reply other threads:[~2019-02-11 4:09 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-25 9:53 [PATCH 0/5] genirq/affinity: introduce .setup_affinity to support allocating interrupt sets Ming Lei
2019-01-25 9:53 ` [PATCH 1/5] genirq/affinity: move allocation of 'node_to_cpumask' to irq_build_affinity_masks Ming Lei
2019-02-07 22:02 ` Bjorn Helgaas
2019-02-10 19:01 ` [tip:irq/core] genirq/affinity: Move allocation of 'node_to_cpumask' to irq_build_affinity_masks() tip-bot for Ming Lei
2019-01-25 9:53 ` [PATCH 2/5] genirq/affinity: allow driver to setup managed IRQ's affinity Ming Lei
2019-02-07 22:21 ` Bjorn Helgaas
2019-02-10 9:22 ` Ming Lei
2019-02-10 16:30 ` Thomas Gleixner
2019-02-11 3:54 ` Ming Lei
2019-02-11 14:39 ` Bjorn Helgaas
2019-02-11 22:38 ` Thomas Gleixner
2019-02-12 11:17 ` Ming Lei
2019-01-25 9:53 ` [PATCH 3/5] genirq/affinity: introduce irq_build_affinity() Ming Lei
2019-01-25 9:53 ` [PATCH 4/5] nvme-pci: simplify nvme_setup_irqs() via .setup_affinity callback Ming Lei
2019-02-10 16:39 ` Thomas Gleixner
2019-02-11 3:58 ` Ming Lei
2019-02-10 18:49 ` Thomas Gleixner
2019-02-11 4:09 ` Ming Lei [this message]
2019-01-25 9:53 ` [PATCH 5/5] genirq/affinity: remove support for allocating interrupt sets Ming Lei
2019-02-07 22:22 ` Bjorn Helgaas
2019-01-25 9:56 ` [PATCH 0/5] genirq/affinity: introduce .setup_affinity to support " Ming Lei
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