From d726280aaf4f1e8d9988c69c1d4fa324357ef255 Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Thu, 25 Jun 2015 11:53:00 +0200 Subject: [PATCH] sched_setaffinity.2: Mention the use of the 'isolcpus' kernel boot option Signed-off-by: Michael Kerrisk --- man2/sched_setaffinity.2 | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/man2/sched_setaffinity.2 b/man2/sched_setaffinity.2 index f4713fd05..79087a5d3 100644 --- a/man2/sched_setaffinity.2 +++ b/man2/sched_setaffinity.2 @@ -204,6 +204,24 @@ will set the attribute for the main thread of the thread group. instead of .BR sched_setaffinity ().) +The +.I isolcpus +boot option can be used to isolate one or more CPUs at boot time, +so that no processes are scheduled onto those CPUs. +Following the use of this boot option, +the only way to schedule processes onto the isolated CPUs is via +.BR sched_setaffinity () +or the +.BR cpuset (7) +mechanism. +For further information, see the kernel source file +.IR Documentation/kernel-parameters.txt . +As noted in that file, +.I isolcpus +is the preferred mechanism of isolating CPUs +(versus the alternative of manually setting the CPU affinity +of all processes on the system). + A child created via .BR fork (2) inherits its parent's CPU affinity mask.