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From: Peter Zijlstra <peterz@infradead.org>
To: Nicholas Piggin <npiggin@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Re: sched_rt_period_timer causing large latencies
Date: Thu, 5 Apr 2018 10:27:01 +0200	[thread overview]
Message-ID: <20180405082701.GL4082@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20180405091138.6ef14d15@roar.ozlabs.ibm.com>

On Thu, Apr 05, 2018 at 09:11:38AM +1000, Nicholas Piggin wrote:
> Hi,
> 
> I'm seeing some pretty big latencies on a ~idle system when a CPU wakes
> out of a nohz idle. Looks like it's due to the taking a lot of remote
> locks and cache lines. irqoff trace:

On RT I think we default RT_RUNTIME_SHARE to false, maybe we should do
the same for mainline. It's always been a dodgy feature and if we ever
figure out how to do FIFO servers this code will be deleted entirely.

  parent reply	other threads:[~2018-04-05  8:27 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-04 23:11 sched_rt_period_timer causing large latencies Nicholas Piggin
2018-04-05  6:46 ` Mike Galbraith
2018-04-05  7:44   ` Nicholas Piggin
2018-04-05  8:11     ` Mike Galbraith
2018-04-05  8:27 ` Peter Zijlstra [this message]
2018-04-05  8:40   ` Mike Galbraith
2018-04-05 10:08     ` Nicholas Piggin
2018-04-05 10:44       ` Nicholas Piggin
2018-04-06 16:23       ` Peter Zijlstra

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