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From: Cinq Prairie <notprairie@gmail.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: Jakub Kicinski <kuba@kernel.org>,
	Stefan Roesch <shr@devkernel.io>,
	io-uring@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] io_uring/napi: don't end the single NAPI busy poll early on need_resched()
Date: Fri, 13 Nov 2026 17:23:47 +0100	[thread overview]
Message-ID: <20261113162347.5617-1-notprairie@gmail.com> (raw)
In-Reply-To: <179426098226.155418.4382559329615606121.b4-ty@b4>

On Mon, 09 Nov 2026 14:49:42 -0700, Jens Axboe wrote:
> Applied, thanks!
>
> [1/1] io_uring/napi: don't end the single NAPI busy poll early on need_resched()
>       commit: 39c7210e970200f8b17de3767c73efe64173a95f

Thanks.

On the cond_resched() follow-up: I no longer think it is worth sending.
Since 7dadeaa6e851 ("sched: Further restrict the preemption modes") in
v7.0, PREEMPT_NONE/PREEMPT_VOLUNTARY can't be selected on archs with
lazy preemption (x86, arm64, ...), so CONFIG_PREEMPTION is always set
there and cond_resched() compiles to a no-op. On those kernels the
need_resched() break in __napi_busy_loop() is already followed by a
preempt_enable() that reschedules, so a yield between laps wouldn't
add anything but a dead cond_resched() call while they are actively
being removed tree-wide.

Unless you'd like it for the few architectures still able to build
PREEMPT_VOLUNTARY, I'll leave it there.

      reply	other threads:[~2026-11-13 16:23 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-27 20:48 Cinq Prairie
2026-11-03 17:44 ` Cinq Prairie
2026-11-09 21:49 ` Jens Axboe
2026-11-13 16:23   ` Cinq Prairie [this message]

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