On Mon, Nov 28, 2022 at 07:23:32PM +0000, Michael Kelley (LINUX) wrote: > From: Gaurav Kohli <gauravkohli@xxxxxxxxxxxxxxxxxxx> Sent: Friday, November 25, 2022 10:15 PM > > > > Hyper-V cleanup code comes under panic path where preemption and irq > > is already disabled. So calling of unregister_syscore_ops might schedule > > out the thread even for the case where mutex lock is free. > > hyperv_cleanup > > unregister_syscore_ops > > mutex_lock(&syscore_ops_lock) > > might_sleep > > Here might_sleep might schedule out this thread, where voluntary preemption > > config is on and this thread will never comes back. And also this was added > > earlier to maintain the symmetry which is not required as this can comes > > during crash shutdown path only. > > > > To prevent the same, removing unregister_syscore_ops function call. > > > > Signed-off-by: Gaurav Kohli <gauravkohli@xxxxxxxxxxxxxxxxxxx> > > --- [...] > > Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> > Applied to hyperv-next. Thanks.
