From: Andi Kleen <ak@suse.de>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [5/6] scheduler: Protect important kernel threads against normalize_rt
Date: Mon, 8 Oct 2007 14:33:34 +0200 [thread overview]
Message-ID: <200710081433.34845.ak@suse.de> (raw)
In-Reply-To: <20071008115142.GE22199@elte.hu>
On Monday 08 October 2007 13:51:42 Ingo Molnar wrote:
>
> * Andi Kleen <ak@suse.de> wrote:
>
> > Not only the migration thread, but also softlockup and stop machine
> > need to be protected against normalize_rt(). Instead of checking for
> > them all I added a new process flag for this.
>
> hm, i dont really like this. The migration thread is an absolute
> exception because it's needed for a correct scheduler. SysRq-N is like
> SysRq-U or SysRq-B - last-minute resort in case something Goes Foul.
> Results are not guaranteed.
softlockup is the same. Just think about it.
If you ever renormalize it and then run a fifo thread it will
starve and then eventually kill the box.
And starving CPU unplug is also equally bad.
-Andi
next prev parent reply other threads:[~2007-10-08 12:34 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-07 20:59 [PATCH] [0/6] Some scheduler changes for sched-devel Andi Kleen
2007-10-07 20:59 ` [PATCH] [1/6] scheduler: Remove some unnecessary gotos in sched.c Andi Kleen
2007-10-08 11:36 ` Ingo Molnar
2007-10-09 19:17 ` Ingo Molnar
2007-10-10 0:55 ` Andi Kleen
2007-10-10 11:25 ` Ingo Molnar
2007-10-10 11:26 ` Ingo Molnar
2007-10-07 20:59 ` [PATCH] [2/6] scheduler: Refactor common code of sleep_on / wait_for_completion Andi Kleen
2007-10-07 22:22 ` [PATCH] [2/6] scheduler: Refactor common code of sleep_on / wait_for_completion v2 Andi Kleen
2007-10-08 11:39 ` Ingo Molnar
2007-10-08 12:03 ` Ingo Molnar
2007-10-07 20:59 ` [PATCH] [3/6] scheduler: Do devirtualization for sched_fair Andi Kleen
2007-10-08 11:42 ` Ingo Molnar
2007-10-08 12:32 ` Andi Kleen
2007-10-08 12:39 ` Ingo Molnar
2007-10-08 14:33 ` Andi Kleen
2007-10-07 20:59 ` [PATCH] [4/6] scheduler: Refactor normalize_rt_tasks Andi Kleen
2007-10-08 11:44 ` Ingo Molnar
2007-10-07 20:59 ` [PATCH] [5/6] scheduler: Protect important kernel threads against normalize_rt Andi Kleen
2007-10-08 11:51 ` Ingo Molnar
2007-10-08 12:33 ` Andi Kleen [this message]
2007-10-08 12:43 ` Ingo Molnar
2007-10-08 13:08 ` Andi Kleen
2007-10-07 20:59 ` [PATCH] [6/6] scheduler: Remove bogus comment in sched_group_set_shares Andi Kleen
2007-10-08 11:52 ` Ingo Molnar
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