Messages in this thread |  | | Date | Fri, 11 Feb 2022 06:19:41 -0800 | From | Yury Norov <> | Subject | Re: [PATCH 22/49] sched: replace cpumask_weight with cpumask_empty where appropriate |
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On Fri, Feb 11, 2022 at 11:19:58AM +0100, Peter Zijlstra wrote: > On Thu, Feb 10, 2022 at 02:49:06PM -0800, Yury Norov wrote: > > In some places, kernel/sched code calls cpumask_weight() to check if > > any bit of a given cpumask is set. We can do it more efficiently with > > cpumask_empty() because cpumask_empty() stops traversing the cpumask as > > soon as it finds first set bit, while cpumask_weight() counts all bits > > unconditionally. > > > > Signed-off-by: Yury Norov <yury.norov@gmail.com> > > Neither of these paths are really performance sentitive, but whatever. > > Do you want me to take this now,
Yes please. Many patches from this series already merged this way.
> or do you want to merge the whole > series somewere else? In which case: > > Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> > > > --- > > kernel/sched/core.c | 2 +- > > kernel/sched/topology.c | 2 +- > > 2 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > > index 28d1b7af03dc..ed7b392945b7 100644 > > --- a/kernel/sched/core.c > > +++ b/kernel/sched/core.c > > @@ -8711,7 +8711,7 @@ int cpuset_cpumask_can_shrink(const struct cpumask *cur, > > { > > int ret = 1; > > > > - if (!cpumask_weight(cur)) > > + if (cpumask_empty(cur)) > > return ret; > > > > ret = dl_cpuset_cpumask_can_shrink(cur, trial); > > diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c > > index d201a7052a29..8478e2a8cd65 100644 > > --- a/kernel/sched/topology.c > > +++ b/kernel/sched/topology.c > > @@ -74,7 +74,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, > > break; > > } > > > > - if (!cpumask_weight(sched_group_span(group))) { > > + if (cpumask_empty(sched_group_span(group))) { > > printk(KERN_CONT "\n"); > > printk(KERN_ERR "ERROR: empty group\n"); > > break; > > -- > > 2.32.0 > >
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