Re: [PATCH 07/14] sched: Fix do_set_cpus_allowed() locking

[Peter Zijlstra]

On Thu, Oct 30, 2025 at 12:12:01AM +0000, Mark Brown wrote:
> On Wed, Sep 10, 2025 at 05:44:16PM +0200, Peter Zijlstra wrote:
> 
> > All callers of do_set_cpus_allowed() only take p->pi_lock, which is
> > not sufficient to actually change the cpumask. Again, this is mostly
> > ok in these cases, but it results in unnecessarily complicated
> > reasoning.
> 
> We're seeing lockups on some arm64 platforms in -next with the LTP
> cpuhotplug02 test, the machine sits there repeatedly complaining that
> RCU is stalled on IPIs:

Did not this help?

  https://lkml.kernel.org/r/20251027110133.GI3245006@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx