Messages in this thread | | | Date | Fri, 25 Mar 2011 10:59:31 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH RFC] x86: avoid atomic operation in test_and_set_bit_lock if possible |
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* Eric Dumazet <eric.dumazet@gmail.com> wrote:
> Le vendredi 25 mars 2011 à 10:32 +0100, Ingo Molnar a écrit : > > * Eric Dumazet <eric.dumazet@gmail.com> wrote: > > > > > Le vendredi 25 mars 2011 à 00:56 +0100, Andi Kleen a écrit : > > > > > never EVER seen any good explanation of why that particular sh*t > > > > > argument would b true. It seems to be purely about politics, where > > > > > some idiotic vendor (namely HP) has convinced Intel that they really > > > > > need it. To the point where some engineers seem to have bought into > > > > > the whole thing and actually believe that fairy tale ("firmware can do > > > > > better" - hah! They must be feeding people some bad drugs at the > > > > > cafeteria) > > > > > > > > For the record I don't think it's a good idea for the BIOS to do > > > > this (and I'm not aware of any engineer who does), > > > > but I think Linux should do better than just disabling PMU use when > > > > this happens. > > > > > > > > However I suspect taking over SCI would cause endless problems > > > > and is very likely not a good idea. > > > > > > I tried many different changes in BIOS and all failed (the machine is > > > damn slow at boot, this takes age). > > > > > > I am stuck :( > > > > Could you please try the patch below? > > This obviously works, [...]
Congrats to your now much-improved perf experience! :-)
> [...] but you probably need to make a full pass to make sure we dont have a > MSR failure -this should return false in this case.
Wanted to keep this patch simple - we are not really hitting MSR failure cases in practice, and by getting the message the user is at least warned that *something* is amiss.
Thanks,
Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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