On 18/01/17 00:30, Dario Faggioli wrote: > Since we are doing cpumask manipulation already, clear a bit > in the mask at once. Doing that will save us an if, later in > the code. > > No functional change intended. > > Signed-off-by: Dario Faggioli <dario.faggi...@citrix.com> > --- > Cc: George Dunlap <george.dun...@eu.citrix.com> > --- > xen/common/sched_credit2.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/xen/common/sched_credit2.c b/xen/common/sched_credit2.c > 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? -George _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
