On Thu, Jul 7, 2022 at 6:22 PM Hugh Dickins <hughd@xxxxxxxxxx> wrote: > > On Fri, 8 Jul 2022, Vlastimil Babka wrote: > > On 7/8/22 00:09, Yu Zhao wrote: > > > On Thu, Jul 7, 2022 at 3:58 PM Vlastimil Babka <vbabka@xxxxxxx> wrote: > > >> > > >> On 7/7/22 22:09, Andrew Morton wrote: > > >> > The patch titled > > >> > Subject: mm-page_alloc-protect-pcp-lists-with-a-spinlock-fix > > >> > has been added to the -mm mm-unstable branch. Its filename is > > >> > mm-page_alloc-protect-pcp-lists-with-a-spinlock-fix.patch > > >> > > > >> > This patch will shortly appear at > > >> > https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_alloc-protect-pcp-lists-with-a-spinlock-fix.patch > > >> > > > >> > This patch will later appear in the mm-unstable branch at > > >> > git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > > >> > > > >> > Before you just go and hit "reply", please: > > >> > a) Consider who else should be cc'ed > > >> > b) Prefer to cc a suitable mailing list as well > > >> > c) Ideally: find the original patch on the mailing list and do a > > >> > reply-to-all to that, adding suitable additional cc's > > >> > > > >> > *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** > > >> > > > >> > The -mm tree is included into linux-next via the mm-everything > > >> > branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm > > >> > and is updated there every 2-3 working days > > >> > > > >> > ------------------------------------------------------ > > >> > From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > > >> > Subject: mm-page_alloc-protect-pcp-lists-with-a-spinlock-fix > > >> > Date: Thu Jul 7 01:06:35 PM PDT 2022 > > >> > > > >> > add missing local_unlock_irqrestore() on contention path > > >> > > >> Doh, that's true and something to fix, although patch 7 did remove the bug > > >> later in the same series so that wouldn't explain the lkp report for patch > > >> 7. The reason lkp test robot complained was AFAICS that it was testing v4, > > >> as I just replied there. > > > > > > Sorry I didn't bother to reply until now: it did test v5, at this > > > commit, not the whole series. > > > > I meant this report that appears to be for v4 (full series including patch 7): > > https://lore.kernel.org/all/YsFk%2FqU+QtWun04h@xsang-OptiPlex-9020/ > > That reported a bug due to missing unpin that was previously reported for v4 > > and fixed in v5. > > > > I'm not aware of a lkp report for v5 (found only Dan's) but yeah, hitting > > the (similar but not identical) bug fixed by this -fix would indeed be > > possible in v5 if patch 7 was not applied. > > This is all very confusing. > > For whatever reason, Mel's 7/7 (and its -fix per Yu Zhao) was not > included in next-20220706 or next-20220707 (I never tried 0705, and > 0704 had none of Mel's series, so no problem in this regard; and > in weeks before that, no time for testing here). > > So when I tried testing on 0706, got plenty of rcu_preempt stalls or > sleeping function called from invalid context (irqs_disabled(): 1) or > other alternative warnings. And found that applying the missing 7/7 > plus -fix (I've never tried 7/7 without -fix) got rid of all those, > allowing to move forward and look into other bugs. > > But now we have a different fix going in, though I thought Andrew > said he wanted to move 7/7 to mm-stable tomorrow (despite its not > even reaching mm-unstable?). Maybe the Oliver Sang lkp testing (on > out-of-date version) cast doubt on v5 7/7 and delayed it going in. > > This relentless drive towards mm-stable: I for one cannot keep up. > I'd like to ask for slowing down a bit - my intention had been to > reach testing maple tree again (it's not yet what I'd call stable), > but this and a couple of other issues got in the way. More mails > to write. Sorry for not being clear (it doesn't seem confusing to me because I don't trust the bot): There were two reports, the first one [1] tested v4 without the fix [2]; the second one [3] tested v5 at patch 5/7 (not the whole series). v4 + the fix is good; v5 the whole series is good. Please do not drop patch 7/7 and do not add this fix. Thanks. [1] https://lore.kernel.org/r/YsFk%2FqU+QtWun04h@xsang-OptiPlex-9020/ [2] https://lore.kernel.org/r/20220615160446.be1f75fd256d67e57b27a9fc@xxxxxxxxxxxxxxxxxxxx/ [3] https://lore.kernel.org/r/202207071103.r5a2F97A-lkp@xxxxxxxxx/
