> When do performance testing on 37-rc1 kernel on Core2 machines, we find
> the volanomark loopback performance drop about 30%, that due to
> commit:fab476228ba37907ad7
>
> Volanomark link:
http://www.volano.com/benchmarks.html
> Our volanomark testing parameters as following:
> "-count 25000 -rooms 10 "
> JVM is jrockit-R27.3.1-jre1.5.0_11
> java_options is "-Xmx1500m -Xms1500m -Xns750m -XXaggressive -Xlargepages
> -XXlazyUnlocking -Xgc:genpar -XXtlasize:min=16k,preferred=64k"
> and we set /proc/sys/kernel/sched_compat_yield as "1".
>
> We find if with the following patch, the regression can be recovered.
>
> Signed-off-by:Alex Shi <alex.shi@intel.com>
>
> diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
> index f4f6a83..5dca678 100644
> --- a/kernel/sched_fair.c
> +++ b/kernel/sched_fair.c
> @@ -1766,7 +1766,6 @@ static void pull_task(struct rq *src_rq, struct task_struct *p,
> check_preempt_curr(this_rq, p, 0);
>
> /* re-arm NEWIDLE balancing when moving tasks */
> - src_rq->avg_idle = this_rq->avg_idle = 2*sysctl_sched_migration_cost;
> this_rq->idle_stamp = 0;
> }
>
>
> It seems some of load_balance() is not necessary that caused by avg_idle
> setting. But do not know more details of the volano running. Anyone like
> to give a comments for this issue?
>
