Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <f1b421f956fa044b4efa7f5fef015725b27223cf.camel@gmx.de>
Subject: Re: wakeup_affine_weight() is b0rked - was Re: [PATCH 2/2]
 sched/fair: Scale wakeup granularity relative to nr_running
From:   Mike Galbraith <efault@gmx.de>
To:     Barry Song <21cnbao@gmail.com>
Cc:     Mel Gorman <mgorman@techsingularity.net>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Valentin Schneider <valentin.schneider@arm.com>,
        Aubrey Li <aubrey.li@linux.intel.com>,
        Barry Song <song.bao.hua@hisilicon.com>,
        Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
        LKML <linux-kernel@vger.kernel.org>
Date:   Mon, 04 Oct 2021 06:34:26 +0200
In-Reply-To: <CAGsJ_4xcRFcDMpuC7vrpHe=aRbDpAnRd1F64aqh2EEcNgmZxCg@mail.gmail.com>
References: <20210920142614.4891-1-mgorman@techsingularity.net>
         <20210920142614.4891-3-mgorman@techsingularity.net>
         <22e7133d674b82853a5ee64d3f5fc6b35a8e18d6.camel@gmx.de>
         <20210921103621.GM3959@techsingularity.net>
         <ea2f9038f00d3b4c0008235079e1868145b47621.camel@gmx.de>
         <02c977d239c312de5e15c77803118dcf1e11f216.camel@gmx.de>
         <CAGsJ_4xcRFcDMpuC7vrpHe=aRbDpAnRd1F64aqh2EEcNgmZxCg@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.42.0 
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Sun, 2021-10-03 at 20:34 +1300, Barry Song wrote:
>
> I am wondering if this should be the responsibility of wake_wide()?

Those event threads we stacked so high (which are kde minions btw),
don't generally accrue _any_ wakee_flips, so when X wakes a slew of the
things, wake_wide()'s heuristic rejects the lot.

So yeah, the blame game for this issue is a target rich environment.
Shoot either of 'em (or both), and you'll hit the bad guy.

	-Mike