Messages in this thread | | | Date | Wed, 23 Sep 2009 12:41:00 +0200 | From | Ingo Molnar <> | Subject | Re: perf sched record hangs machine |
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* Cyrill Gorcunov <gorcunov@gmail.com> wrote:
> On 9/23/09, Ingo Molnar <mingo@elte.hu> wrote: > > > > * Chris Malley <mail@chrismalley.co.uk> wrote: > > > >> 2009/9/23 Cyrill Gorcunov <gorcunov@gmail.com>: > >> > > >> > Btw, meanwhile Chris may try to pass lapic boot-option in attempt to > >> > reenable apic via msr registers. Also (iirc) i feel we may be hiding > >> > errors if complete noop apic would be used since i belive we need to > >> > check out under which condition a particular operation is called and > >> > when apic is disabled it's mean we're switched to UP mode and > >> > inter-cpu interrupts are under suspicion too. Will take a look during > >> > ~6 hours ;) > >> > > >> > >> Hi Cyrill > >> > >> Heh, yes that just occurred to me as well. With the lapic boot option > >> I can't reproduce the problem, and get a good recording every time. > >> Don't know why the BIOS had disabled it (can't see any specific > >> option). > > > > Would still be important to fix the crash - there are boxes where lapics > > are disabled permanently and cannot be re-enabled. (plus most people > > dont touch their defaults and dont add funky boot options - so crashing > > is not an option) > > > > Ingo, Chris, could you try Peter's patch? It seems like what we need.
It should fix the problem, but also the underlying uncleanliness should be fixed as well. We need an apic_none driver template with safe methods. Then all the scattered 'is the lapic enabled' open-coded checks of global flags can be removed.
Ingo
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