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Date:   Fri, 23 Jun 2023 08:37:26 +0200
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     John Johansen <john.johansen@canonical.com>
Cc:     Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Swapnil Sapkal <Swapnil.Sapkal@amd.com>,
        Peter Zijlstra <peterz@infradead.org>,
        linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org,
        Aaron Lu <aaron.lu@intel.com>, x86@kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [tip: sched/core] sched: Fix performance regression introduced
 by mm_cid
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On 2023-06-21 16:59:31 [-0700], John Johansen wrote:
> > Which turned a per-cpu cache into a global memory pool protected by a spinlock. It may benefit RT, but it does not appear to be so great at scaling.
> > 
> it is not. And I have a patch that needs some more formal testing for some stats.
> Ubuntu pulled it in last cycle so it has gotten a fair bit of use and is looking good
> on that end. There are probably some tweaks that can be done to improve it. The
> backoff in particular is something that has mostly been adjusted in response to some
> basic benchmarking.
> 
> anyways patch below
> 
> commit e057e9b47f1749882ea0efb4427d6b9671c761ab

I think I've been looking at this patch, or a former version of it, and
it looked good.

Sebastian