Re: [resubmit] Re: [patch-final] Re: patch] cpusets, cgroups:disallow attaching kthreadd

From: Andrew Morton
Date: Fri Jan 06 2012 - 17:06:26 EST


On Wed, 07 Dec 2011 05:36:57 +0100
Mike Galbraith <efault@xxxxxx> wrote:

> cpusets, cgroups: disallow attaching kthreadd
>
> Allowing kthreadd to be moved to a non-root group makes no sense, it being
> a global resource, and needlessly leads unsuspecting users toward trouble.
>
> 1. An RT workqueue worker thread spawned in a task group with no rt_runtime
> allocated is not schedulable. Simple user error, but harmful to the box.
>
> 2. A worker thread which acquires PF_THREAD_BOUND can never leave a cpuset,
> rendering the cpuset immortal.
>
> Save the user some unexpected trouble, just say no.

Someone's been screwing around in linux-next during the merge window.
afacit some patch which was previously there has magically disappeared.
That killed your patch - the original version of the
kernel/sched/core.c chagne applies to the new linux-next but the
kernel/cpuset.c part is all wrecked.

There's been a lot of screwing around this time. There were a large
number of rejects merging current linux-next onto current mainline this
morning due to conflicting changes in tools/perf/.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/