Messages in this thread | | | Date | Tue, 14 Apr 2015 17:26:45 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH v8 2/2] nohz: set isolcpus when nohz_full is set |
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On Tue, Apr 14, 2015 at 11:17:55AM -0400, Chris Metcalf wrote: > 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: Frederic Weisbecker <fweisbec@gmail.com>
No need to put my ack, since I'll add my Signed-off-by when I apply the patches. Note this won't go through this merge window though as we are in the middle of it already.
Peter, are you ok with these two patches?
Thanks.
> Acked-by: Mike Galbraith <umgwanakikbuti@gmail.com> ["thumbs up!"] > Acked-by: Rik van Riel <riel@redhat.com> > Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> > --- > v8: no change in this patch, just in 1/2 > Add Frederic's Ack > > v7: oops, use add_cpus_to, not remove_cpus_from [Frederic] > > v6: back to just using a direct update, with the new names > > v5: test run of Frederic's proposal to use sched_isolated_map_add() > > v4: update accessor names to make them clearer [PeterZ] > > v3: update changelog language to avoid using unclear "implies" [PeterZ] > > v2: add Mike and Rik's Acked-by > > kernel/sched/core.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index f0f831e8a345..4a5681b5a4fd 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -7031,6 +7031,9 @@ 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(); > > /* > -- > 2.1.2 >
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