RE: [PATCH] scheduler: domain: init next_balance in nohz_idle_balancer with jiffies

Diwakar Tundlam
2012-01-31T19:18:41Z

Yes, the change should be ported to kernel/sched/fair.c under init_sched_fair_class(). But that's for 3.3. I will send a separate patch for 3.3 shortly.

All previous kernels have the old structure where the patch can be applied as it is.

--Diwakar.

-----Original Message-----
From: Peter Zijlstra [mailto:peterz@infradead.org]
Sent: Tuesday, January 31, 2012 7:45 AM
To: Peter De Schrijver
Cc: Diwakar Tundlam; Ingo Molnar; linux-kernel@vger.kernel.org
Subject: Re: [PATCH] scheduler: domain: init next_balance in nohz_idle_balancer with jiffies

On Mon, 2012-01-30 at 14:44 +0200, Peter De Schrijver wrote:
> From: Diwakar Tundlam <dtundlam@nvidia.com>
>
> The next_balance parameter of nohz_idle_balancer should be initialized
> to jiffies since jiffies itself is initialized to 300 seconds shy of
> overflow. Otherwise, nohz_idle_balancer does not run for the first 5
> mins after bootup.
>
> Signed-off-by: Diwakar Tundlam <dtundlam@nvidia.com>
> Reviewed-by: Aleksandr Frid <afrid@nvidia.com>
> Reviewed-by: Peter Boonstoppel <pboonstoppel@nvidia.com>
> Reviewed-by: Satya Popuri <spopuri@nvidia.com>
> ---
> kernel/sched.c | 1 +
> 1 files changed, 1 insertions(+), 0 deletions(-)

You'll find that this file no longer exists...

> diff --git a/kernel/sched.c b/kernel/sched.c index b5efd6c..d3f291f
> 100644
> --- a/kernel/sched.c
> +++ b/kernel/sched.c
> @@ -8383,6 +8383,7 @@ void __init sched_init(void)
> atomic_set(&nohz.load_balancer, nr_cpu_ids);
> atomic_set(&nohz.first_pick_cpu, nr_cpu_ids);
> atomic_set(&nohz.second_pick_cpu, nr_cpu_ids);
> + nohz.next_balance = jiffies;
> #endif
> /* May be allocated at isolcpus cmdline parse time */
> if (cpu_isolated_map == NULL)

Not does this code section..