On 09/04, Andrew Morton wrote: > > On Sat, 3 Sep 2022 08:43:30 +0200 Oleksandr Natalenko <oleksandr@xxxxxxxxxx> wrote: > > > @@ -535,6 +539,7 @@ void do_coredump(const kernel_siginfo_t *siginfo) > > */ > > .mm_flags = mm->flags, > > .vma_meta = NULL, > > + .cpu = raw_smp_processor_id(), > > }; > > Why use the "raw_" function here? To avoid check_preemption_disabled() from debug_smp_processor_id(). We do not disable preemption because this is pointless, this is the "racy snapshot" anyway. The coredumping task can migrate to another CPU even before get_signal/do_coredump, right after exit-to-user path enables irqs. Oleg.
