Re: [rfc patch] sched/fair: Use instantaneous load for fork/exec balancing

From: Matt Fleming
Date: Tue Jul 12 2016 - 07:14:16 EST


On Mon, 11 Jul, at 09:58:52AM, Dietmar Eggemann wrote:
> This difference in the initial se->avg.load_avg value [0 or 1024] has an
> influence in wake_affine() [weight = p->se.avg.load_avg;] for the wakeup
> handling of the hackbench tasks in the 'send/receive data' phase.

The way I was running hackbench made it very susceptible to changes in
fork behaviour, i.e. running it with a small number of loops.

> There are a couple of patches on tip/sched/core which might change the
> behaviour of this: fork path, no double attach_entity_load_avg for new
> task, no remove_entity_load_avg for new task, changes in effective_load ...

Indeed they do! Things are much improved when running the latest
tip/sched/core, thanks for the pointer.