First off: David, Filipe, many thx for your answers, that helped me a lot to get a better picture of the situation! On 08.04.22 17:55, Filipe Manana wrote: > On Fri, Apr 08, 2022 at 04:52:22PM +0200, David Sterba wrote: >> On Fri, Apr 08, 2022 at 12:32:20PM +0200, Thorsten Leemhuis wrote: >>> Hi, this is your Linux kernel regression tracker. Top-posting for once, >>> to make this easily accessible to everyone. >>> >>> Btrfs maintainers, what's up here? Yes, this regression report was a bit >>> confusing in the beginning, but Bruno worked on it. And apparently it's >>> already fixed in 5.16, but still in 5.15. Is this caused by a change >>> that is to big to backport or something? >> >> I haven't identified possible fixes in 5.16 so I can't tell how much >> backport efforts it could be. As the report is related to performance on >> package updates, my best guess is that the patches fixing it are those >> from Filipe related to fsync/logging, and there are several of such >> improvements in 5.16. Or something else that fixes it indirectly. > > So there's a lot of confusion in the thread, Yeah, definitely. That basically why I had hoped from a rough assessment from the btrfs maintainers. > and the original openSUSE > bugzilla [1] is also a bit confusing and large to follow. > > Let me try to make it clear: > > 1) For some reason, outside btrfs' control, inode eviction is triggered > a lot on 5.15 kernels in Bruno's test machine when doing package > installations/updates with zypper. So I assume there are no other reports like this? Great! > [...] > 6) In short, it is not known what causes the excessive evictions on 5.15 > on his machine for that specific workload - we don't have a commit to > point at and say it caused a regression. [...] Bruno, under these circumstances I'd say you need to bisect this to get us closer to the root of the problem (and a fix for it). Sadly that how it is sometimes, as briefly explained here: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/admin-guide/reporting-regressions.rst#n140 > This thread is also basically a revamp of an older thread [3]. > > [1] https://bugzilla.opensuse.org/show_bug.cgi?id=1193549 > [2] https://lore.kernel.org/linux-btrfs/cover.1642676248.git.fdmanana@xxxxxxxx/ > [3] https://lore.kernel.org/linux-fsdevel/MN2PR20MB251235DDB741CD46A9DD5FAAD24E9@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ Yeah, but it was this thread that made me aware of the issue -- and just like [3] it didn't get a single reply from a btrfs maintainer, so I had to assume the report was ignored. A quick "we have no idea what my cause this issue and it's the only report with such symptoms so far; could you please bisect" would have made me happy already. :-D Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) P.S.: As the Linux kernel's regression tracker I'm getting a lot of reports on my table. I can only look briefly into most of them and lack knowledge about most of the areas they concern. I thus unfortunately will sometimes get things wrong or miss something important. I hope that's not the case here; if you think it is, don't hesitate to tell me in a public reply, it's in everyone's interest to set the public record straight.
