On Sun, May 17, 2026 at 09:11:10PM +0200, Thorsten Leemhuis wrote: > On 5/17/26 20:03, Paul E. McKenney wrote: > > On Sun, May 17, 2026 at 02:47:55PM +0200, Uladzislau Rezki wrote: > >> On Wed, May 13, 2026 at 12:38:01PM +0200, Thorsten Leemhuis wrote: > >>> On 5/11/26 19:54, Uladzislau Rezki (Sony) wrote: > >>>> From: "Paul E. McKenney" <[email protected]> > >>>> > >>>> While an srcu_struct structure is in the midst of switching from CPU-0 > >>>> to all-CPUs state, it can attempt to invoke callbacks for CPUs that > >>>> have never been online. Worse yet, it can attempt in invoke callbacks > >>>> for CPUs that never will be online, even including imaginary CPUs not in > >>>> cpu_possible_mask. This can cause hangs on s390, > >>> > >>> Uladzislau, Paul, according to the fixes tag below this change fixes a > >>> change that went into 7.0-rc6 -- and apparently causes a "hang" on some > >>> architectures. So shouldn't this be heading to mainline instead of > >>> -next? Ideally with a stable tag to ensure backporting to 7.0.y, but > >>> that is a separate decision? > >>>
FWIW, I'm happy to create an urgent PR to Linus with this fix. Since it fixes a commit in the previous urgent fix PR from me. Ulad, let me know if you want me to do it. Regards, Boqun > >> I assume it will be picked to stable > > Thx for the reply. This answered the second aspect I raised. What about > the first: shouldn't this be heading to mainline this cycle, ideally > quite soon? Or is this the plan and I misinterpreted the "-next" in the > subject? > > Sadly Jiri (now CCed) afaics didn't yet report if this fix helped to fix > the issues they were seeing, but it sounded a lot like it was likely: > https://lore.kernel.org/all/[email protected]/ > > >> since there is a "Fixes:" tag. From > >> the other hand i can explicitly update commit message with Cc: > >> [email protected] > >> > >> Paul, any thoughts? > > > > The "Fixes" tag should cover it. > > Often it does, yes, but it might be silently dropped for one reason or > another. So in the end only a stable tag will guarantee backporting > attempt by the stable team. > > Site note: I recently also tried to persuade Greg to also take those > with a stable tag first in case there is a huge backlog. > > Ciao, Thorsten
