Messages in this thread | | | Date | Fri, 26 Oct 2018 06:57:10 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH AUTOSEL 4.4 08/65] btrfs: cleaner_kthread() doesn't need explicit freeze |
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On Fri, Oct 26, 2018 at 08:58:57AM +0200, Jiri Kosina wrote: >On Thu, 25 Oct 2018, Sasha Levin wrote: > >> >> cleaner_kthread() is not marked freezable, and therefore calling >> >> try_to_freeze() in its context is a pointless no-op. >> >> >> >> In addition to that, as has been clearly demonstrated by 80ad623edd2d >> >> ("Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()"), it's perfectly >> >> valid / legal for cleaner_kthread() to stay scheduled out in an arbitrary >> >> place during suspend (in that particular example that was waiting for >> >> reading of extent pages), so there is no need to leave any traces of >> >> freezer in this kthread. >> >> >> >> Fixes: 80ad623edd2d ("Revert "btrfs: clear PF_NOFREEZE in >> >> Fixes: cleaner_kthread()") >> >> Fixes: 696249132158 ("btrfs: clear PF_NOFREEZE in cleaner_kthread()") >> >> Signed-off-by: Jiri Kosina <jkosina@suse.cz> >> >> Signed-off-by: David Sterba <dsterba@suse.com> >> >> Signed-off-by: Sasha Levin <sashal@kernel.org> >> > >> >IIRC it was some preparatory work for livepatching. I did a quick check >> >if this is safe for 4.4 and would say yes, but the patch does not fix >> >anything so IMO this does not need to go to stable. >> >> Doesn't that also affect hibernation and such? > >This patch just removes pointless try_to_freeze(), that's guaranteed not >to do anything and return immediately, as the btrfs kthread is not >freezable. >So I don't think it's needed in stable; the semantics is equivalent before >and after.
Gotcha. I'll drop it. Thank you!
-- Thanks, Sasha
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