From: Mel Gorman <mgorman@techsingularity.net>
To: Mike Galbraith <efault@gmx.de>
Cc: Barry Song <21cnbao@gmail.com>,
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>
Subject: Re: wakeup_affine_weight() is b0rked - was Re: [PATCH 2/2] sched/fair: Scale wakeup granularity relative to nr_running
Date: Tue, 5 Oct 2021 08:47:19 +0100 [thread overview]
Message-ID: <20211005074719.GP3959@techsingularity.net> (raw)
In-Reply-To: <4f571c5c759b9d356d1bb4114fb169181194a780.camel@gmx.de>
On Mon, Oct 04, 2021 at 11:06:30AM +0200, Mike Galbraith wrote:
> On Mon, 2021-10-04 at 06:34 +0200, Mike Galbraith wrote:
> > 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.
>
> The mallet below convinced wake_wide() that X waking event threads is
> something it most definitely should care about. It's not perfect, can
> get caught with its pants down, because behavior changes a LOT, but I
> at least have to work at it a bit to stack tasks to the ceiling.
>
> With make -j8 running along with firefox with two tabs, one containing
> youtube's suggestions of stuff you probably don't want to watch, the
> other a running clip, if I have the idle tab in focus, and don't drive
> mouse around, flips decay enough for wake_wide() to lose interest, but
> just wiggle the mouse, and it starts waking wide. Focus on the running
> clip, and it continuously wakes wide.
>
> Hacky, but way better behavior.. at this particular testcase.. in this
> particular box.. at least once :)
>
Only three machines managed to complete tests overnight. For most
workloads test, it was neutral or slight improvements. For
multi-kernbench__netperf-tcp-rr-multipair (kernel compile +
netperf-tcp-rr combined), there was little to no change.
For the heavy overloaded cases (hackbench again), it was variable. Worst
improvement was a gain of 1-3%. Best improvement (single socket skylake
with 8 logical CPUs SMT enabled) was 1%-18% depending on the group
count.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2021-10-05 7:47 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-20 14:26 [PATCH 0/2] Scale wakeup granularity relative to nr_running Mel Gorman
2021-09-20 14:26 ` [PATCH 1/2] sched/fair: Remove redundant lookup of rq in check_preempt_wakeup Mel Gorman
2021-09-21 7:21 ` Vincent Guittot
2021-09-21 7:53 ` Mel Gorman
2021-09-21 8:12 ` Vincent Guittot
2021-09-21 8:21 ` Peter Zijlstra
2021-09-21 10:03 ` Mel Gorman
2021-09-20 14:26 ` [PATCH 2/2] sched/fair: Scale wakeup granularity relative to nr_running Mel Gorman
2021-09-21 3:52 ` Mike Galbraith
2021-09-21 5:50 ` Mike Galbraith
2021-09-21 7:04 ` Mike Galbraith
2021-09-21 10:36 ` Mel Gorman
2021-09-21 12:32 ` Mike Galbraith
2021-09-21 14:03 ` Mel Gorman
2021-10-05 9:24 ` Peter Zijlstra
2021-09-22 5:22 ` Mike Galbraith
2021-09-22 13:20 ` Mel Gorman
2021-09-22 14:04 ` Mike Galbraith
2021-09-22 14:15 ` Vincent Guittot
2021-09-22 15:04 ` Mel Gorman
2021-09-22 16:00 ` Vincent Guittot
2021-09-22 17:38 ` Mel Gorman
2021-09-22 18:22 ` Vincent Guittot
2021-09-22 18:57 ` Mel Gorman
2021-09-23 1:47 ` Mike Galbraith
2021-09-23 8:40 ` Vincent Guittot
2021-09-23 9:21 ` Mike Galbraith
2021-09-23 12:41 ` Vincent Guittot
2021-09-23 13:14 ` Mike Galbraith
2021-09-27 11:17 ` Mel Gorman
2021-09-27 14:17 ` Mike Galbraith
2021-10-04 8:05 ` Mel Gorman
2021-10-04 16:37 ` Vincent Guittot
2021-10-05 7:41 ` Mel Gorman
2021-09-27 14:19 ` Vincent Guittot
2021-09-27 15:02 ` Mel Gorman
2021-09-23 12:24 ` Phil Auld
2021-10-05 10:36 ` Peter Zijlstra
2021-10-05 14:12 ` Phil Auld
2021-10-05 14:32 ` Peter Zijlstra
2021-10-05 10:28 ` Peter Zijlstra
2021-10-05 10:23 ` Peter Zijlstra
2021-10-05 9:41 ` Peter Zijlstra
2021-09-22 15:05 ` Vincent Guittot
2021-10-05 9:32 ` Peter Zijlstra
2021-10-03 3:07 ` wakeup_affine_weight() is b0rked - was " Mike Galbraith
2021-10-03 7:34 ` Barry Song
2021-10-03 14:52 ` Mike Galbraith
2021-10-03 21:06 ` Barry Song
2021-10-04 1:49 ` Mike Galbraith
2021-10-04 4:34 ` Mike Galbraith
2021-10-04 9:06 ` Mike Galbraith
2021-10-05 7:47 ` Mel Gorman [this message]
2021-10-05 8:42 ` Mike Galbraith
2021-10-05 9:31 ` Mel Gorman
2021-10-06 6:46 ` Mike Galbraith
2021-10-08 5:06 ` Mike Galbraith
2021-09-21 8:03 ` Vincent Guittot
2021-09-21 10:45 ` Mel Gorman
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