Re: [tip:sched/core] sched/fair: Clean up scale confusion

From: Yuyang Du
Date: Thu May 12 2016 - 23:23:56 EST


On Thu, May 12, 2016 at 03:31:27AM -0700, tip-bot for Peter Zijlstra wrote:
> Commit-ID: 1be0eb2a97d756fb7dd8c9baf372d81fa9699c09
> Gitweb: http://git.kernel.org/tip/1be0eb2a97d756fb7dd8c9baf372d81fa9699c09
> Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> AuthorDate: Fri, 6 May 2016 12:21:23 +0200
> Committer: Ingo Molnar <mingo@xxxxxxxxxx>
> CommitDate: Thu, 12 May 2016 09:55:33 +0200
>
> sched/fair: Clean up scale confusion
>
> Wanpeng noted that the scale_load_down() in calculate_imbalance() was
> weird. I agree, it should be SCHED_CAPACITY_SCALE, since we're going
> to compare against busiest->group_capacity, which is in [capacity]
> units.
>
> Reported-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Cc: Mike Galbraith <efault@xxxxxx>
> Cc: Morten Rasmussen <morten.rasmussen@xxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Yuyang Du <yuyang.du@xxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>

It is good that this issue is addressed and patch merged, however, for the
record, Vincent has already had a solution for this, and we had a patch,
including other cleanups (the latest version is: https://lkml.org/lkml/2016/5/3/925).
And I think Ben first pointed this out (and we then attempted to address it)
as far as I can tell.