On Mon, 6 Aug 2018 at 12:08, Dietmar Eggemann <dietmar.eggemann@xxxxxxx> wrote:
On 08/06/2018 10:40 AM, Vincent Guittot wrote:
On Fri, 3 Aug 2018 at 17:55, Quentin Perret <quentin.perret@xxxxxxx> wrote:
On Friday 03 Aug 2018 at 15:49:24 (+0200), Vincent Guittot wrote:
On Fri, 3 Aug 2018 at 10:18, Quentin Perret <quentin.perret@xxxxxxx> wrote:
On Friday 03 Aug 2018 at 09:48:47 (+0200), Vincent Guittot wrote:
On Thu, 2 Aug 2018 at 18:59, Quentin Perret <quentin.perret@xxxxxxx> wrote:
I think we're discussing two different things right now:
1. Should forkees go in find_energy_efficient_cpu() ?
2. Should forkees have 0 of initial util_avg when EAS is enabled ?
It's the same topic: How EAS should consider a newly created task ?
For now, we let the "performance" mode selects a CPU. This CPU will
most probably be worst CPU from a EAS pov because it's the idlest CPU
in the idlest group which is the opposite of what EAS tries to do
The current behavior is :
For every new task, the cpu selection is done assuming it's a heavy
task with the max possible load_avg, and it looks for the idlest cpu.
This means that if the system is lightly loaded, scheduler will select
most probably a idle big core.
AFAICS, task load doesn't seem to be used for find_idlest_cpu() (
find_idlest_group() and find_idlest_group_cpu()). So the forkee
(SD_BALANCE_FORK) is placed independently of his task load.
hmm ... so what is used if load or runnable load are not used ?
find_idlest_group() uses load and runnable load but skip spare
capacity in case of fork