Re: [PATCH 0/3] resend, cpuset/hotplug fixes

[Peter Zijlstra]

On Fri, 2009-09-11 at 15:15 +0800, Lai Jiangshan wrote:
> One other minor thing:
> Oleg's patch may introduce a trouble in PREEEMPT_RT tree, because
> spinlock in RT is also mutex. Likely I'm wrong.

But they have priority-inheritance, hence you cannot create a deadlock
through preemption. If the kstopmachine thread blocks on a mutex, the
owner gets boosted to kstopmachine's prio and runs to completion, after
that kstopmachine continues.