On Mon, Aug 28, 2017 at 3:15 PM, Takashi Iwai <tiwai@xxxxxxx> wrote: > On Mon, 28 Aug 2017 15:06:00 +0200, > Adam Borowski wrote: >> >> On Mon, Aug 28, 2017 at 02:26:06PM +0200, Takashi Iwai wrote: >> > I seem to get a kernel warning when running KVM on Dell desktop with >> > IvyBridge like below. As you can see, a bad page BUG is triggered >> > after that, too. The problem is not triggered always, but it happens >> > occasionally. >> >> See the thread starting with 20170820231302.s732zclznrqxwr46@xxxxxxxxxx >> >> > I haven't seen this on 4.13-rc4 at all, and IIRC, it started happening >> > since rc5. So this might be a regression at rc5. But, as it doesn't >> > happen always, I can't be 100% sure about it, and it's quite difficult >> > to bisect (the test case isn't reliable), unfortunately. >> >> Same here -- it sometimes takes a few hours of trying to reproduce, which >> makes proving the negative greatly unpleasant. >> >> And all I've been able to tell so far is that the problem is between >> 4.13-rc4 and 4.13-rc5, just like you say. > > Good to hear that we can chorus! > So if it's really a regression between rc4 and rc5, I see no obvious > changes in arch/x86, i.e. it's likely somewhere else. > > (snip) >> The first WARN is always the above. But the rest seems to be totally random >> -- a nasty case of fandango on core whose results range from harmless >> through crash to massive data loss (just guess what would happen if some >> idiot picked balancing the disk as a test load -- no one would be that >> stupid, right? At least an incomplete idiot has checksums and backups). > > Yeah, the crash after the WARNING seems quite random. I don't see that warning but running qemu-kvm crashed by laptop (4.13-rc4) two times in a row and some userspace applications such has firefox or bash crashed randomly. pstore-efi is now enabled to capture the stacktrace. -- Thanks, //richard
