From: Hugh Dickins <hughd@google.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>,
linux-kernel@vger.kernel.org, rdunlap@infradead.org,
joel@joelfernandes.org, Ingo Molnar <mingo@kernel.org>,
juri.lelli@redhat.com, vincent.guittot@linaro.org,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, mgorman@suse.de, bristot@redhat.com,
Valentin Schneider <valentin.schneider@arm.com>
Subject: Re: [PATCH] sched: Add CONFIG_SCHED_CORE help text
Date: Tue, 25 May 2021 15:17:22 -0700 (PDT) [thread overview]
Message-ID: <alpine.LSU.2.11.2105251510590.2465@eggly.anvils> (raw)
In-Reply-To: <YKyhtwhEgvtUDOyl@hirez.programming.kicks-ass.net>
On Tue, 25 May 2021, Peter Zijlstra wrote:
> Subject: sched: Add CONFIG_SCHED_CORE help text
> From: Peter Zijlstra <peterz@infradead.org>
> Date: Tue May 25 08:53:28 CEST 2021
>
> Hugh noted that the SCHED_CORE Kconfig option could do with a help
> text.
>
> Requested-by: Hugh Dickins <hughd@google.com>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Thanks,
Acked-by: Hugh Dickins <hughd@google.com>
if necessary (but there's more than enough of me there already).
> ---
> kernel/Kconfig.preempt | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> --- a/kernel/Kconfig.preempt
> +++ b/kernel/Kconfig.preempt
> @@ -104,4 +104,18 @@ config SCHED_CORE
> bool "Core Scheduling for SMT"
> default y
> depends on SCHED_SMT
> + help
> + This option permits Core Scheduling, a means of coordinated task
> + selection across SMT siblings. When enabled -- see
> + prctl(PR_SCHED_CORE) -- task selection ensures that all SMT siblings
> + will execute a task from the same 'core group', forcing idle when no
> + matching task is found.
> +
> + Use of this feature includes:
> + - mitigation of some (not all) SMT side channels;
> + - limiting SMT interference to improve determinism and/or performance.
> +
> + SCHED_CORE is default enabled when SCHED_SMT is enabled -- when
> + unused there should be no impact on performance.
> +
next prev parent reply other threads:[~2021-05-25 22:17 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-21 3:06 config SCHED_CORE Hugh Dickins
2021-05-21 7:53 ` Peter Zijlstra
2021-05-21 11:18 ` Joel Fernandes
2021-05-21 11:57 ` Joel Fernandes
2021-05-21 13:33 ` Peter Zijlstra
2021-05-24 20:50 ` Joel Fernandes
2021-05-23 10:57 ` Peter Zijlstra
2021-05-23 20:30 ` Hugh Dickins
2021-05-23 21:31 ` Randy Dunlap
2021-05-21 16:09 ` Randy Dunlap
2021-05-25 7:05 ` [PATCH] sched: Add CONFIG_SCHED_CORE help text Peter Zijlstra
2021-05-25 17:24 ` Randy Dunlap
2021-05-25 22:17 ` Hugh Dickins [this message]
2021-06-01 14:04 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
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