From: Rik van Riel <riel@fb.com>
To: "peterz@infradead.org" <peterz@infradead.org>
Cc: "joe.lawrence@redhat.com" <joe.lawrence@redhat.com>,
"song@kernel.org" <song@kernel.org>,
Song Liu <songliubraving@fb.com>,
"jpoimboe@redhat.com" <jpoimboe@redhat.com>,
"mingo@redhat.com" <mingo@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"live-patching@vger.kernel.org" <live-patching@vger.kernel.org>,
Kernel Team <Kernel-team@fb.com>,
"vincent.guittot@linaro.org" <vincent.guittot@linaro.org>
Subject: Re: [RFC] sched,livepatch: call klp_try_switch_task in __cond_resched
Date: Mon, 9 May 2022 01:07:50 +0000 [thread overview]
Message-ID: <2202e0d211338d7641046fd8f05608b0dbaf7f78.camel@fb.com> (raw)
In-Reply-To: <20220508204101.GB76023@worktop.programming.kicks-ass.net>
On Sun, 2022-05-08 at 22:41 +0200, Peter Zijlstra wrote:
>
> No, it does what you think it should do, you're just getting confused
> by
> the inverted PREEMPT_NEED_RESCHED bit :-)
Fair enough, that makes sense! Thanks for pointing that out.
That is a very clever optimization.
I suppose that should_resched() check is also something that
KLP could use by periodically poking tasks that get stuck in
the KLP transition (and are running) by simply calling
set_preempt_need_resched(), after which that klp_patch_pending()
check can happen only in the __cond_resched() path where we
already call preempt_schedule_common() anyway?
Is that something that would work, and be low enough overhead
in the general case to be acceptable?
next prev parent reply other threads:[~2022-05-09 1:29 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-07 17:46 Song Liu
2022-05-07 18:26 ` Rik van Riel
2022-05-07 19:04 ` Song Liu
2022-05-07 19:18 ` Rik van Riel
2022-05-08 20:41 ` Peter Zijlstra
2022-05-09 1:07 ` Rik van Riel [this message]
2022-05-09 7:04 ` Peter Zijlstra
2022-05-09 8:06 ` Song Liu
2022-05-09 9:38 ` Peter Zijlstra
2022-05-09 14:13 ` Rik van Riel
2022-05-09 15:22 ` Petr Mladek
2022-05-09 15:07 ` Petr Mladek
2022-05-09 16:22 ` Song Liu
2022-05-10 7:56 ` Petr Mladek
2022-05-10 13:33 ` Rik van Riel
2022-05-10 15:44 ` Petr Mladek
2022-05-10 16:07 ` Rik van Riel
2022-05-10 16:52 ` Josh Poimboeuf
2022-05-10 18:07 ` Rik van Riel
2022-05-10 18:42 ` Josh Poimboeuf
2022-05-10 19:45 ` Song Liu
2022-05-10 23:04 ` Josh Poimboeuf
2022-05-10 23:57 ` Song Liu
2022-05-11 0:33 ` Josh Poimboeuf
2022-05-11 9:24 ` Petr Mladek
2022-05-11 16:33 ` Song Liu
2022-05-12 4:07 ` Josh Poimboeuf
2022-05-13 12:33 ` Petr Mladek
2022-05-13 13:34 ` Peter Zijlstra
2022-05-11 0:35 ` Rik van Riel
2022-05-11 0:37 ` Josh Poimboeuf
2022-05-11 0:46 ` Rik van Riel
2022-05-11 1:12 ` Josh Poimboeuf
2022-05-11 18:09 ` Rik van Riel
2022-05-12 3:59 ` Josh Poimboeuf
2022-05-09 15:52 ` [RFC] sched,livepatch: call stop_one_cpu in klp_check_and_switch_task Rik van Riel
2022-05-09 16:28 ` Song Liu
2022-05-09 18:00 ` Josh Poimboeuf
2022-05-09 19:10 ` Rik van Riel
2022-05-09 19:17 ` Josh Poimboeuf
2022-05-09 19:49 ` Rik van Riel
2022-05-09 20:09 ` Josh Poimboeuf
2022-05-10 0:32 ` Song Liu
2022-05-10 9:35 ` Peter Zijlstra
2022-05-10 1:48 ` Rik van Riel
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