On Fri, Apr 10, 2015 at 04:53:52PM -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. > > Signed-off-by: Chris Metcalf <[email protected]> > --- > 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] > > 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); > +
I can't say I like this, but I can not come up with a better name. So that patch is ok to me (if Peterz acks it) :-) > sched_init_numa(); > > /* > -- > 2.1.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
