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From: Daniel Bristot de Oliveira <bristot@redhat.com>
To: Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	Clark Williams <williams@redhat.com>,
	"Luis Claudio R . Goncalves" <lgoncalv@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] sched/rt: Document RT_RUNTIME_SHARE sched feature
Date: Tue, 15 Nov 2016 11:39:11 +0100	[thread overview]
Message-ID: <dc42945fc19eacd41acebc2be2425a4d9af2b82b.1479204252.git.bristot@redhat.com> (raw)
In-Reply-To: <cover.1479204252.git.bristot@redhat.com>

Add a comment explaining the RT_RUNTIME_SHARE sched feature.

Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Cc: linux-kernel@vger.kernel.org

diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 5fffebfe..531c4bb 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -65,7 +65,17 @@ SCHED_FEAT(RT_PUSH_IPI, true)
 #endif
 
 SCHED_FEAT(FORCE_SD_OVERLAP, false)
+
+/*
+ * Enables the sharing of rt_runtime between CPUs, allowing a CPU to
+ * run a real-time task up to 100% of the time while leaving more
+ * space for non-real-time tasks to run on the CPU that lend rt_runtime.
+ *
+ * WARNING: This may allow the starvation of non-real-time tasks pinned
+ * to the CPU in which a spinning rt-task runs forever.
+ */
 SCHED_FEAT(RT_RUNTIME_SHARE, false)
+
 SCHED_FEAT(LB_MIN, false)
 SCHED_FEAT(ATTACH_AGE_LOAD, true)
 
-- 
2.7.4

  parent reply	other threads:[~2016-11-15 10:39 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-15 10:39 [PATCH 0/2] sched/rt: disable RT_RUNTIME_SHARE by default and document it Daniel Bristot de Oliveira
2016-11-15 10:39 ` [PATCH 1/2] sched/rt: Disable RT_RUNTIME_SHARE by default Daniel Bristot de Oliveira
2016-11-15 10:39 ` Daniel Bristot de Oliveira [this message]
2016-11-15 13:01 ` [PATCH 0/2] sched/rt: disable RT_RUNTIME_SHARE by default and document it Luis Claudio R. Goncalves
2016-11-15 15:27 ` Steven Rostedt
2016-11-15 16:57   ` Daniel Bristot de Oliveira

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