Geert Uytterhoeven writes: > Hi Mikael, > > On Tue, May 31, 2016 at 12:06 PM, Mikael Pettersson > <[email protected]> wrote: > > Finn Thain writes: > > > On Sun, 21 Feb 2016, Mikael Pettersson wrote: > > > > I've done two git bisects on this. The first one was inconclusive > > > > (pointed to a harmless commit), but the second one ended up with: > > > > > > > > # first bad commit: [ac4de9543aca59f2b763746647577302fbedd57e] Merge > > branch 'akpm' (patches from Andrew Morton) > > > > > > > > That's a big pile of VM changes, so I think it could be the culprit. > > > > > > I think this issue may date back to v2.6.38 or earlier. > > > > > > The redhat.com bug report was closed in 2012 but Fedora users were still > > > seeing the problem after it was supposedly fixed. > > > https://bugzilla.redhat.com/show_bug.cgi?id=712019 > > > > > > That page also has a link to the bug report for Ubuntu: > > > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/484045 > > > > > > BTW, I came across this recently: "Rik van Riel pointed out that [the > > > kswapd thread] tends to be slow for [the purpose of compaction], and it > > > can get stuck in a shrinker somewhere waiting for a lock." > > > http://lwn.net/Articles/684611/ > > > > > > Perhaps a stack trace would help to ascertain whether this is the same > > > known bug or not (?) > > > > > > -- > > > > FWIW, my latest round(s) of bisects identified the following: > > > > fdbadebec27cc92358ed4f593e8763cf10b82687 is the first bad commit > > commit fdbadebec27cc92358ed4f593e8763cf10b82687 > > Author: Li Zefan <[email protected]> > > Date: Thu Sep 12 15:13:19 2013 -0700 > > > > memcg: remove redundant code in mem_cgroup_force_empty_write() > > > > vfs guarantees the cgroup won't be destroyed, so it's redundant to get > > a > > css reference. > > > > Signed-off-by: Li Zefan <[email protected]> > > Acked-by: Michal Hocko <[email protected]> > > Cc: KAMEZAWA Hiroyuki <[email protected]> > > Cc: Johannes Weiner <[email protected]> > > Cc: Tejun Heo <[email protected]> > > Signed-off-by: Andrew Morton <[email protected]> > > Signed-off-by: Linus Torvalds <[email protected]> > > > > :040000 040000 1f6b5b056995067c7c60e6f87e9cd1f181e8fbeb > > ea29d63e70ce2320e144fac7b157a146d41360bf M mm > > > > This appears to be the first commit in the merge (git bisect refuses to > > bisect before it), so either it's it or the problem predates the merge. > > That's upstream commit c33bd8354f3a3bb26a98d2b6bf600b7b35657328? > > Well done! Looks indeed like a suspect for the behavior you're seeing. > I suppose you will follow up with the mm people?
Alas, this was a false find. This commit is definitely in the bad range, but reverting it from 3.12.60 doesn't eliminate the kswapd bug. I'll have to bisect mainline again. -- To unsubscribe from this list: send the line "unsubscribe linux-m68k" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
