From: Jason Andryuk <jandryuk@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: Calling queue_work() multiple times with the same work_struct
Date: Thu, 20 May 2021 13:31:01 -0400 [thread overview]
Message-ID: <CAKf6xpsv-v0kMXnuOVmkjOXYV+R=HPnKWL9cufZaNEa6+3jvMw@mail.gmail.com> (raw)
In-Reply-To: <YKaV5ej3WrUJQa7/@slm.duckdns.org>
Hello, Tejun.
On Thu, May 20, 2021 at 1:01 PM Tejun Heo <tj@kernel.org> wrote:
>
> Hello, Jason.
>
> On Thu, May 20, 2021 at 08:39:56AM -0400, Jason Andryuk wrote:
> > 1 & 2 look supported from workqueue.h. Is the 3rd case true and
> > guaranteed? Is it okay to re-use the same work_struct in that case
>
> Yes.
>
> > while it's being executed? A work_struct function can re-queue
>
> Yes.
>
> > itself, so I hope #3 is supported.
>
> Yes.
>
> > DECLARE_WORK(argo_work, argo_work_fn);
> > static struct workqueue_struct *argo_wq = alloc_workqueue("argo_wq",
> > WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_SYSFS, 1);
>
> I don't know what the device is but does it need both HIGHPRI and
> CPU_INTENSIVE?
argo is a Xen inter-vm communication mechanism, so networking-ish. I
wanted HIGHPRI to ensure it is run promptly. I wasn't sure about
CPU_INTENSIVE, but high data rates could potentially copy a fair
amount of data. HIGHPRI alone may be sufficient.
> > static void argo_work_fn(struct work_struct *work)
> > {
> > argo_interrupt_rx(); /* iterates multiple "rings" */
> > argo_notify();
> > }
> >
> > static irqreturn_t argo_interrupt(int irq, void *dev_id)
> > {
> > queue_work(argo_wq, &argo_work);
> >
> > return IRQ_HANDLED;
> > }
>
> Yeah, the above will guarantee that the work function would run at least
> once since the last invocation of argo_interrupt().
Awesome. Thank you, Tejun.
Regards,
Jason
prev parent reply other threads:[~2021-05-20 17:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-20 12:39 Calling queue_work() multiple times with the same work_struct Jason Andryuk
2021-05-20 17:01 ` Tejun Heo
2021-05-20 17:31 ` Jason Andryuk [this message]
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