Messages in this thread | | | Date | Mon, 07 Apr 2014 21:49:48 +0200 | From | Michele Ballabio <> | Subject | Re: Bisected KVM hang on x86-32 between v3.12 and v3.13 |
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On 07/04/2014 17:07, Peter Zijlstra wrote: > 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.
Understood.
>> 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?
It is fixed on current -master (3.14.0-10773-gb8780c3).
Thanks.
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