Messages in this thread | | | Subject | Re: [PATCH] perf_events: improve DS/BTS/PEBS buffer allocation | From | Peter Zijlstra <> | Date | Mon, 13 Sep 2010 17:16:40 +0200 |
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On Mon, 2010-09-13 at 17:13 +0200, Stephane Eranian wrote: > > For now I think you can not do this. vmalloc'ed memory can't be safely > > accessed from NMIs in x86 because that might fault. And faults from NMIs > > are not supported. They cause very bad things: return from fault calls > > iret which reenables NMI, so NMI can nest but in the meantime there is > > only one NMI stack, so that gets quickly messed up. > > > What kind of faults are you talking about here? TLB faults?
Page faults. vmalloc pte setup is lazy.
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