From: "tip-bot2 for Peter Zijlstra" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>,
Randy Dunlap <rdunlap@infradead.org>,
Hugh Dickins <hughd@google.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: sched/core] sched: Add CONFIG_SCHED_CORE help text
Date: Tue, 01 Jun 2021 14:04:57 -0000 [thread overview]
Message-ID: <162255629757.29796.5663233849330605967.tip-bot2@tip-bot2> (raw)
In-Reply-To: <YKyhtwhEgvtUDOyl@hirez.programming.kicks-ass.net>
The following commit has been merged into the sched/core branch of tip:
Commit-ID: 7b419f47facd286c6723daca6ad69ec355473f78
Gitweb: https://git.kernel.org/tip/7b419f47facd286c6723daca6ad69ec355473f78
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Tue, 25 May 2021 08:53:28 +02:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Tue, 01 Jun 2021 16:00:10 +02:00
sched: Add CONFIG_SCHED_CORE help text
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>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Hugh Dickins <hughd@google.com>
Link: https://lkml.kernel.org/r/YKyhtwhEgvtUDOyl@hirez.programming.kicks-ass.net
---
kernel/Kconfig.preempt | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index ea1e333..bd7c414 100644
--- 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.
+
prev parent reply other threads:[~2021-06-01 14:05 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
2021-06-01 14:04 ` tip-bot2 for Peter Zijlstra [this message]
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