Re: [tip:sched/urgent] sched: Set correct normal_prio and prio values in sched_fork()

From: Arve Hjønnevåg
Date: Sat Dec 12 2009 - 00:55:47 EST


On Mon, Oct 5, 2009 at 3:47 AM, tip-bot for Peter Williams
<pwil3058@xxxxxxxxxxxxxx> wrote:
> Commit-ID:  f83f9ac2632732bd1678150b5a03d152f912fe72
> Gitweb:     http://git.kernel.org/tip/f83f9ac2632732bd1678150b5a03d152f912fe72
> Author:     Peter Williams <pwil3058@xxxxxxxxxxxxxx>
> AuthorDate: Thu, 24 Sep 2009 06:47:10 +0000
> Committer:  Ingo Molnar <mingo@xxxxxxx>
> CommitDate: Mon, 5 Oct 2009 13:42:20 +0200
>
> sched: Set correct normal_prio and prio values in sched_fork()
>
> normal_prio should be updated if policy changes from RT to
> SCHED_MORMAL or if static_prio/nice is changed.
>
> Some paths through sched_fork() ignore this requirement and may
> result in normal_prio having an invalid value.
>
> Fixing this issue allows the call to effective_prio() in
> wake_up_new_task() to be removed.
>

This change causes a lot of threads with a 0 nice value to get a prio
value of 140 instead of 120 (at least on my android arm msm build). I
don't know if this has any impact on how they are scheduled since the
load weight is unaffected, but it at least makes the output of ps more
confusing.

--
Arve Hjønnevåg
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