Re: [PATCH v2] sched/all: Change all BUG_ON() instances in the scheduler to WARN_ON_ONCE()

From: John Hubbard
Date: Tue Aug 16 2022 - 01:33:55 EST


On 8/15/22 07:41, Mel Gorman wrote:
For the rest, I didn't see obvious recovery paths that would allow the
system to run predictably. Any of them firing will have unpredictable
consequences (e.g. move_queued_task firing would be fun if it was a per-cpu
kthread). Depending on which warning triggers, the remaining life of the
system may be very short but maybe long enough to be logged even if system
locks up shortly afterwards.

Hi Mel,

Are you basically saying, "WARN_ON*() seems acceptable in mm/, because
we can at least get the problem logged before it locks up, probably"?

Or are you implying that we should instead introduce and use some new
PANIC_ON() or VM_PANIC_ON() set of macros that would allow proper "log
then reboot" behavior?


thanks,
--
John Hubbard
NVIDIA