On Monday 29 October 2012 06:57 PM, Vincent Guittot wrote:
On 24 October 2012 17:21, Santosh Shilimkar santosh.shilimkar@ti.com wrote:
On Sunday 07 October 2012 01:13 PM, Vincent Guittot wrote:
Look for an idle CPU close the pack buddy CPU whenever possible.
s/close/close to
yes
The goal is to prevent the wake up of a CPU which doesn't share the power line of the pack CPU
Signed-off-by: Vincent Guittot vincent.guittot@linaro.org
kernel/sched/fair.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6df53b5..f76acdc 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5158,7 +5158,25 @@ static struct {
static inline int find_new_ilb(int call_cpu) {
struct sched_domain *sd; int ilb = cpumask_first(nohz.idle_cpus_mask);int buddy = per_cpu(sd_pack_buddy, call_cpu);/** If we have a pack buddy CPU, we try to run load balance on aCPU
* that is close to the buddy.*/if (buddy != -1)for_each_domain(buddy, sd) {if (sd->flags & SD_SHARE_CPUPOWER)continue;Do you mean SD_SHARE_POWERLINE here ?
No, I just don't want to take hyperthread level for ILB
ilb = cpumask_first_and(sched_domain_span(sd),nohz.idle_cpus_mask);if (ilb < nr_cpu_ids)break;} if (ilb < nr_cpu_ids && idle_cpu(ilb)) return ilb;Can you please expand "idle CPU _close_ the pack buddy CPU" ?
The goal is to packed the tasks on the pack buddy CPU so when the scheduler needs to start ILB, I try to wake up a CPU that is close to the buddy and preferably in the same cluster
I see your point now. Thanks for clarification.
Regards santosh