From: Rik van Riel <riel@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, Kirill Tkhai <ktkhai@parallels.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Nicolas Pitre <nicolas.pitre@linaro.org>,
mingo@kernel.org, pjt@google.com
Subject: Re: [PATCH] sched: update last_balance only when actually balanced
Date: Tue, 22 Jul 2014 11:46:39 -0400 [thread overview]
Message-ID: <53CE875F.5040007@redhat.com> (raw)
In-Reply-To: <20140722120445.GB3935@laptop>
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On 07/22/2014 08:04 AM, Peter Zijlstra wrote:
>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index
>> 45943b2..4f7fee2 100644 --- a/kernel/sched/fair.c +++
>> b/kernel/sched/fair.c @@ -7187,7 +7187,9 @@ static void
>> rebalance_domains(struct rq *rq, enum cpu_idle_type idle) */ idle
>> = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE; } - sd->last_balance
>> = jiffies; + /* Only update if we actually balanced. */ + if
>> (continue_balancing) + sd->last_balance = jiffies; interval =
>> get_sd_balance_interval(sd, idle != CPU_IDLE); } if
>> (need_serialize)
>
> Did you actually see any difference with this patch?
>
> The reason I'm asking is that the sched_domains are per cpu, so
> the above assignment is only visible to that particular cpu, not
> other cpus.
It was past 2AM, it may have been a placebo effect :)
Back to the drawing board, to figure out why the load balancing code
is not working quite as expected...
- --
All rights reversed
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prev parent reply other threads:[~2014-07-22 15:47 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-22 6:21 [PATCH] sched: update last_balance only when actually balanced Rik van Riel
2014-07-22 12:04 ` Peter Zijlstra
2014-07-22 15:46 ` Rik van Riel [this message]
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