(adding others suggested by get_maintainer.pl)
On 27/05/2026 15:16, Mark Tomlinson wrote: > Using the PowerPC P2040 (e500mc) CPU, soft lockups can occasionally be > seen in smp_call_function_many_cond(). The conclusion is that this CPU > does not process the doorbell interrupt while in a data-storage (MMU) > exception. If more than one CPU in a multi core environment is calling > this function at the same time, it is possible for a deadlock to occur. > > The fix for this is to call flush_smp_call_function_queue() before > waiting for responses from other CPUs. If there is something in the > queue, this is a good time to process it before busy-waiting on other > CPUs. On other architectures this call will quickly do nothing, as the > queue will be empty. > > Signed-off-by: Mark Tomlinson <[email protected]> > --- > kernel/smp.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/smp.c b/kernel/smp.c > index a0bb56bd8dda..3c4467654ab0 100644 > --- a/kernel/smp.c > +++ b/kernel/smp.c > @@ -884,6 +884,8 @@ static void smp_call_function_many_cond(const struct > cpumask *mask, > local_irq_restore(flags); > } > > + flush_smp_call_function_queue(); > + > if (run_remote && wait) { > for_each_cpu(cpu, cfd->cpumask) { > call_single_data_t *csd;
