Re: [sched_ext/for-6.11]: Issue with BPF Scheduler during CPU Hotplug

[Tejun Heo]

Hello,

On Fri, Aug 23, 2024 at 02:50:01PM +0530, Aboorva Devarajan wrote:
...
> I applied this patch to the almost latest sched-ext (for-6.12) branch upto
> commit 89909296a51e792 ("sched_ext: Don't use double locking to migrate
> tasks across CPUs") and let the test run for over 20 hours, and it completed
> without any hangs on both x86 and PowerPC.
> 
> So, indeed, making sure that both scx_fork_rwsem and cpu_hotplug_lock (read)
> are only held together simulataneously when they can both be acquired seems
> to be resolving the deadlock.

Thanks a lot for confirming. Let me think it over a bit re. what should be
applied.

Thanks.

-- 
tejun