I've added this to my to-do list. On May 4, 2014 at 3:58:01 PM CDT, Richard Weinberger <richard@nod.at> wrote:Am 04.05.2014 22:37, schrieb Hugh Dickins:> On Sat, 3 May 2014, Richard Weinberger wrote:>> On Thu, May 1, 2014 at 6:20 PM, Richard Weinberger>>  wrote:>>> On Wed, Apr 16, 2014 at 10:40 PM, Hugh Dickins  wrote:>>>>>>>> Help!>>>>>> Using a trinity as of today I'm able to trigger this bug on UML within seconds.>>> If you want me to test patch, I can help.>>>>>> I'm also observing one strange fact, I can trigger this on any kernel version.>>> So far I've managed UML to crash on 3.0 to 3.15-rc...>>>> After digging deeper into UML's mmu and tlb code I've found issues and>> fixed them.>>>> But I'm still facing this issue. Although triggering the BUG_ON() is>> not so easy as before>> I can trigger "BUG: Bad rss-counter ..." very easily.>> Now the interesting fact, with my UML mmu and flb fixes applied it>> happens only on kernels >= 3.14.>> If it helps I can try to bisect it.> > Thanks a lot for trying, but from other mail it looks like your> bisection got blown off course ;(Yeah, looks like the issue I'm facing on UML is a completely differentstory. Although the symptoms are identical. :-(> I expect for the moment you'll want to concentrate on getting UML's> TLB flushing back on track with 3.15-rc.This is what I'm currently doing. But it might take some timeas I'm a mm novice.> Once you have that sorted out, I wouldn't be surprised if the same> changes turn out to fix your "Bad rss-counter"s on 3.14 also.> > If not, and if you do still have time to bisect back between 3.13 and> 3.14 to find where things went wrong, it will be a bit tedious in that> you would probably have to apply> > 887843961c4b "mm: fix bad rss-counter if remap_file_pages raced migration"> 7e09e738afd2 "mm: fix swapops.h:131 bug if remap_file_pages raced migration"> > at each stage, to avoid those now-known bugs which trinity became rather> good at triggering. Perhaps other fixes needed, those the two I remember.> > Please don't worry if you don't have time for this, that's understandable.> > Or is UML so contrary that one of those commits actually brings on the> problem for you?Hehe, no. I gave it a quick try, both 887843961c4b and 7e09e738afd2seem to be unrelated to the issues I see.Thanks,//richard--To unsubscribe from this list: send the line "unsubscribe linux-kernel" inthe body of a message to majordomo@vger.kernel.orgMore majordomo info at http://vger.kernel.org/majordomo-info.htmlPlease read the FAQ at http://www.tux.org/lkml/