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. Hugh
