>>> On 18.01.17 at 11:21, <george.dun...@citrix.com> wrote: > On 18/01/17 00:30, Dario Faggioli wrote: >> index ef8e0d8..d086264 100644 >> --- a/xen/common/sched_credit2.c >> +++ b/xen/common/sched_credit2.c >> @@ -985,7 +985,7 @@ runq_tickle(const struct scheduler *ops, struct >> csched2_vcpu *new, s_time_t now) >> cpumask_andnot(&mask, &rqd->active, &rqd->idle); >> cpumask_andnot(&mask, &mask, &rqd->tickled); >> cpumask_and(&mask, &mask, new->vcpu->cpu_hard_affinity); >> - if ( cpumask_test_cpu(cpu, &mask) ) >> + if ( __cpumask_test_and_clear_cpu(cpu, &mask) ) > > Since we're micro-optimizing -- isn't test-and-clear a locked operation? > Would that be more expensive than the if() statement below?
cpumask_test_and_clear_cpu() is, but __cpumask_test_and_clear_cpu() isn't. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
