Messages in this thread | | | Date | Tue, 18 Mar 2014 22:42:11 -0400 | From | Sasha Levin <> | Subject | Re: bad rss-counter message in 3.14rc5 |
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On 03/18/2014 10:12 PM, Hugh Dickins wrote: > On Tue, 18 Mar 2014, Sasha Levin wrote: >> On 03/18/2014 08:38 PM, Hugh Dickins wrote: >>> On Tue, 11 Mar 2014, Dave Jones wrote: >>>> On Tue, Mar 11, 2014 at 09:36:03PM +0400, Cyrill Gorcunov wrote: >>>> > On Tue, Mar 11, 2014 at 01:10:45PM -0400, Dave Jones wrote: >>>> > > > >>>> > > > Dave, iirc trinity can write log file pointing which exactly >>>> syscall sequence >>>> > > > was passed, right? Share it too please. >>>> > > >>>> > > Hm, I may have been mistaken, and the damage was done by a previous >>>> run. >>>> > > I went from being able to reproduce it almost instantly to now not >>>> being able >>>> > > to reproduce it at all. Will keep trying. >>>> > >>>> > Sasha already gave a link to the syscalls sequence, so no rush. >>>> >>>> It'd be nice to get a more concise reproducer, his list had a little of >>>> everything in there. >>> >>> I've so far failed to find any explanation for your swapops.h BUG; >>> but believe I have identified one cause for "Bad rss-counter"s. >>> >>> My hunch is that the swapops.h BUG is "nearby", but I just cannot >>> fit it together (the swapops.h BUG comes when rmap cannot find all >>> all the migration entries it inserted earlier: it's a very useful >>> BUG for validating rmap). >>> >>> Untested patch below: I can't quite say Reported-by, because it may >>> not even be one that you and Sasha have been seeing; but I'm hopeful, >>> remap_file_pages is in the list. >>> >>> Please give this a try, preferably on 3.14-rc or earlier: I've never >>> seen "Bad rss-counter"s there myself (trinity uses remap_file_pages >>> a lot more than most of us); but have seen them on mmotm/next, so >>> some other trigger is coming up there, I'll worry about that once >>> it reaches 3.15-rc. >> >> The patch fixed the "Bad rss-counter" errors I've been seeing both in >> 3.14-rc7 and -next. > > Great, thanks a lot, Sasha. I was afraid that you'd hit those swapops > BUGs, which seemed perhaps to be paired with these; but glad to hear > a positive. Let's see how Dave fares. (I've not forgotten shmem > fallocate, by the way, but those probably aren't as high on my agenda > as you'd like.)
I do hit the swapops issue a lot, I didn't think that your patch was supposed to fix that so I didn't mention it.
Thanks for keeping shmem in mind, I've removed shmem from testing for now but I agree, it's not one of the more important issues to be taken care of.
Thanks, Sasha
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