Messages in this thread | | | Date | Mon, 7 Apr 2014 17:07:05 +0200 | From | Peter Zijlstra <> | Subject | Re: Bisected KVM hang on x86-32 between v3.12 and v3.13 |
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On Mon, Apr 07, 2014 at 05:03:37PM +0200, Peter Zijlstra wrote: > So what I suspect at this point is that because i386 and x86_64 have a > difference in current_thread_info() (i386 is stack based), we end up > setting the TIF_NEED_RESCHED bit on the wrong stack. > > Now I have some vague memories of propagating the TIF flags on stack > switch, but I cannot remember what arch we did that for. Let me stare at > this a little more. > > Also, IFF this is the case, then the fingered patch above (and your > suggested 'fix') aren't the real curlpit/cure but simply make it > more/less likely to happen. > > Now, Steve had a patch somewhere that would make i386 use per-cpu > variables for current_thread_info() just like x86_64 already does I > think. Let me go find them too.
Ohh, goodie, they're already in Linus' tree. Could you see if current git still suffers this problem?
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