All of lore.kernel.org
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Yury Norov <yury.norov@gmail.com>
Cc: linux-kernel@vger.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: Re: [PATCH] irq: simplify irq_im_handle_irq()
Date: Mon, 21 Jul 2025 17:44:16 +0200	[thread overview]
Message-ID: <87o6tdtupb.ffs@tglx> (raw)
In-Reply-To: <aH5OUChoFx55WnVG@yury>

On Mon, Jul 21 2025 at 10:27, Yury Norov wrote:
> On Mon, Jul 21, 2025 at 04:07:22PM +0200, Thomas Gleixner wrote:
> find_next_bit() and for_each_bit() cannot be used in concurrent
> environment, and having atomic clear_bit() is meaningless here.
> Two concurrent processes, if running in parallel, may pick the
> same offset, ending up executing the handle_simple_irq() twice.

The irq work cannot be run in parallel on multiple CPUs. It's guaranteed
that only one irq work handler runs at a time. So irq_sim_handle_irq()
is fully serialized by the irq work magic.

But the bitmap can be modified concurrently, which is not a problem.

Thanks,

        tglx



  reply	other threads:[~2025-07-21 15:44 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-19 21:18 [PATCH] irq: simplify irq_im_handle_irq() Yury Norov
2025-07-21 14:07 ` Thomas Gleixner
2025-07-21 14:27   ` Yury Norov
2025-07-21 15:44     ` Thomas Gleixner [this message]
2025-07-31  8:02       ` Jiri Slaby
2025-07-22  8:11 ` Jiri Slaby

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87o6tdtupb.ffs@tglx \
    --to=tglx@linutronix.de \
    --cc=bartosz.golaszewski@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=yury.norov@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.