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From: Peter Zijlstra <peterz@infradead.org>
To: Aaron Lu <aaron.lu@intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	linux-kernel@vger.kernel.org, Olivier Dion <odion@efficios.com>,
	michael.christie@oracle.com
Subject: Re: [RFC PATCH v4] sched: Fix performance regression introduced by mm_cid
Date: Wed, 12 Apr 2023 16:26:16 +0200	[thread overview]
Message-ID: <20230412142616.GI628377@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20230412114240.GA155547@ziqianlu-desk2>

On Wed, Apr 12, 2023 at 07:42:40PM +0800, Aaron Lu wrote:

> I *guess* you might be able to see some contention with hackbench on
> that HSW-EX system with v4.

Indeed! Notably it seems to be the wakeup from idle that trips it
hardest:

11.31%     0.03%  swapper          [kernel.vmlinux]            [k] schedule_idle
        |
        --11.28%--schedule_idle
                  |
                  --11.27%--__schedule
                            |
                            |--8.61%--mm_cid_get
                            |          |
                            |           --5.78%--_raw_spin_lock
                            |                     |
                            |                      --5.56%--native_queued_spin_lock_slowpath
                            |
                            |--0.81%--finish_task_switch.isra.0
                            |          |
                            |           --0.69%--asm_sysvec_call_function_single
                            |                     |
                            |                      --0.58%--sysvec_call_function_single
                            |
                            --0.57%--switch_mm_irqs_off
                    
                    


  reply	other threads:[~2023-04-12 14:26 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-10 15:01 [RFC PATCH v4] sched: Fix performance regression introduced by mm_cid Mathieu Desnoyers
2023-04-10 21:51 ` michael.christie
2023-04-11  4:52 ` Aaron Lu
2023-04-11 13:12   ` Aaron Lu
2023-04-12  9:10     ` Peter Zijlstra
2023-04-12 11:42       ` Aaron Lu
2023-04-12 14:26         ` Peter Zijlstra [this message]
2023-04-12 14:39           ` Aaron Lu
2023-04-13 11:10             ` Peter Zijlstra
2023-04-13 13:49               ` Aaron Lu
2023-04-13 13:56               ` Mathieu Desnoyers
2023-04-13 15:20                 ` Peter Zijlstra
2023-04-13 15:37                   ` Mathieu Desnoyers
2023-04-12  4:27 ` Aaron Lu
2023-04-12 20:57   ` Mathieu Desnoyers
2023-04-13 13:13     ` Aaron Lu
2023-04-13 13:38       ` Mathieu Desnoyers

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