Messages in this thread | | | Date | Tue, 21 Jul 2020 14:17:52 +0200 | From | Michal Hocko <> | Subject | Re: [RFC PATCH] mm: silence soft lockups from unlock_page |
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On Tue 21-07-20 07:44:07, Qian Cai wrote: > > > > On Jul 21, 2020, at 7:25 AM, Michal Hocko <mhocko@kernel.org> wrote: > > > > Are these really important? I believe I can dig that out from the bug > > report but I didn't really consider that important enough. > > Please dig them out. We have also been running those things on > “large” powerpc as well and never saw such soft-lockups. Those > details may give us some clues about the actual problem.
I strongly suspect this is not really relevant but just FYI this is 16Node, 11.9TB with 1536CPUs system.
> Once we > understand the problem better, we may judge if this “hack” is > really worth it.
I do not have access to the machine so I can only judge from the boot log I have in hands. And from that it is pretty clear that $ grep BUG tmp/attachment.txt | wc -l 896
$ grep BUG tmp/attachment.txt | grep "\[systemd" | wc -l 860
$ grep do_fault+0x448 tmp/attachment.txt | wc -l 860
that the boot struggles, lockups happen from udev workers and most of them are stuck at the very same place which is unlock_page. The rest is a part of the changelog. -- Michal Hocko SUSE Labs
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