nohz: Set isolcpus when nohz_full is set

nohz_full is only useful with isolcpus are also set, since
otherwise the scheduler has to run periodically to try to
determine whether to steal work from other cores.

Accordingly, when booting with nohz_full=xxx on the command
line, we should act as if isolcpus=xxx was also set, and set
(or extend) the isolcpus set to include the nohz_full cpus.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Jones <davej@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430928266-24888-5-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This commit is contained in:

Chris Metcalf

2015-05-06 18:04:26 +02:00

committed by

Ingo Molnar

parent 83dedea8a0

commit 8cb9764fc8

1 changed files with 3 additions and 0 deletions

									
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kernel/sched/core.c

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				@ -7036,6 +7036,9 @@ void __init sched_init_smp(void)

					alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);

					alloc_cpumask_var(&fallback_doms, GFP_KERNEL);

					/* nohz_full won't take effect without isolating the cpus. */

					tick_nohz_full_add_cpus_to(cpu_isolated_map);

					sched_init_numa();

					/*

nohz: Set isolcpus when nohz_full is set

3 kernel/sched/core.c Unescape Escape View File

3

kernel/sched/core.c

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