From: Chris Metcalf <cmetc...@ezchip.com> nohz_full is only useful with isolcpus 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. Acked-by: Mike Galbraith <umgwanakikb...@gmail.com> ["thumbs up!"] Acked-by: Rik van Riel <r...@redhat.com> Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Chris Metcalf <cmetc...@ezchip.com> Cc: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com> Cc: Rafael J. Wysocki <rafael.j.wyso...@intel.com> Cc: Martin Schwidefsky <schwidef...@de.ibm.com> Cc: Mike Galbraith <umgwanakikb...@gmail.com> Cc: Ingo Molnar <mi...@redhat.com> Cc: Rik van Riel <r...@redhat.com> Signed-off-by: Frederic Weisbecker <fweis...@gmail.com> --- kernel/sched/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 6f149f8..e95b4d8 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7042,6 +7042,9 @@ 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(); /* -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/