On Fri, Oct 08, 2021 at 01:15:27PM +0200, Peter Zijlstra wrote:

Hi,

This fixes up wchan which is various degrees of broken across the
architectures.

Patch 4 fixes wchan for x86, which has been returning 0 for the past many
releases.

Patch 5 fixes the fundamental race against scheduling.

Patch 6 deletes a lot and makes STACKTRACE unconditional

patch 7 fixes up a few STACKTRACE arch oddities

0day says all builds are good, so it must be perfect :-) I'm planning on
queueing up at least the first 5 patches, but I'm hoping the last two patches
can be too.

Also available here:

  git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/wchan

These patches introduce a regression on ARM. Whereas before, I have
/proc/*/wchan populated with non-zero values, with these patches they
_all_ contain "0":

root@clearfog21:~# cat /proc/*/wchan
0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000root@clearfog21:~#

I'll try to investigate what is going on later today.

-- 
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