Messages in this thread | | | Date | Wed, 26 Nov 2014 06:24:52 +0100 | From | Juergen Gross <> | Subject | Re: frequent lockups in 3.18rc4 |
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On 11/26/2014 06:09 AM, Linus Torvalds wrote: > > On Nov 25, 2014 8:39 PM, "Jürgen Groß" <jgross@suse.com > <mailto:jgross@suse.com>> wrote: > > > > I COULD trigger it with 3.17. Took much longer, but I've seen it once. > > And from Xen hypervisor data it was clear it was the same bug (cpu > > spinning in pmd_lock()). > > I'm still hoping you can give a back trace. I'd like to know what access > it is that can trigger this, and preferably what the call chain to it was...
Working on it. Triggering it via sysrq(l) isn't working: machine hung up. I'll try a dump, but this might take some time due to the machine size...
If this isn't working I can always modify the hypervisor to show me more of the kernel stack in that situation. This will be a pure dump, but it should be possible to extract the back trace from that.
> > I do believe it happened in 3.17, I just want to understand the but more > - not just apply the fix..
Sure.
> > Most of Dave's lockup back traces did not have the whole page fault in > them, so while Dave has seen this too, there might be different symptoms...
Stay tuned... :-)
Juergen
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