Messages in this thread | | | Date | Tue, 5 Oct 2021 08:47:19 +0100 | From | Mel Gorman <> | Subject | Re: wakeup_affine_weight() is b0rked - was Re: [PATCH 2/2] sched/fair: Scale wakeup granularity relative to nr_running |
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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
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