Re: [PATCH 00/24] Complete EEVDF

From: Hongyan Xia
Date: Tue Aug 27 2024 - 05:46:08 EST


On 22/08/2024 16:55, Peter Zijlstra wrote:
On Wed, Aug 21, 2024 at 10:46:07AM +0100, Hongyan Xia wrote:
Okay, in case the trace I provided isn't clear enough, I traced the crash to
a call chain like this:

dl_server_start()
enqueue_dl_entity()
update_stats_enqueue_dl()
update_stats_enqueue_sleeper_dl()
__schedstats_from_dl_se()
dl_task_of() <---------- crash

If I undefine CONFIG_SCHEDSTATS, then it boots fine, and I wonder if this is
the reason why other people are not seeing this. This is probably not EEVDF
but DL refactoring related.

Thanks for the report -- I'll see if I can spot something. Since you
initially fingered these eevdf patches, could you confirm or deny that
changing:

kernel/sched/features.h:SCHED_FEAT(DELAY_DEQUEUE, true)

to false, makes any difference in the previously failing case?

Sadly the issue persists. I'm seeing exactly the same backtrace on my Juno board.