From: Borislav Petkov <bp@amd64.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
Andi Kleen <andi@firstfloor.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Jack Steiner <steiner@sgi.com>, Jan Beulich <JBeulich@novell.com>,
Borislav Petkov <bp@amd64.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Nick Piggin <npiggin@kernel.dk>,
"x86@kernel.org" <x86@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@redhat.com>, "tee@sgi.com" <tee@sgi.com>,
Nikanth Karthikesan <knikanth@suse.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Robert Richter <robert.richter@amd.com>
Subject: Re: [PATCH RFC] x86: avoid atomic operation in test_and_set_bit_lock if possible
Date: Fri, 25 Mar 2011 11:50:55 +0100 [thread overview]
Message-ID: <20110325105055.GA7281@aftab> (raw)
In-Reply-To: <20110325095931.GA31903@elte.hu>
On Fri, Mar 25, 2011 at 05:59:31AM -0400, Ingo Molnar wrote:
> > [...] 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.
AFAIR, Robert was telling me couple of months ago about some braindead
BIOSes doing power management by using at least one perf counter. A
radical approach like that might interfere with that BIOS since it will
try to reprogram the counter continuously and f*ck up OS PMU use.
Anyway, adding Robert for clarification.
--
Regards/Gruss,
Boris.
Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
General Managers: Alberto Bozzo, Andrew Bowd
Registration: Dornach, Gemeinde Aschheim, Landkreis Muenchen
Registergericht Muenchen, HRB Nr. 43632
next prev parent reply other threads:[~2011-03-25 10:51 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-24 4:56 [PATCH RFC] x86: avoid atomic operation in test_and_set_bit_lock if possible Nikanth Karthikesan
2011-03-24 8:52 ` Jan Beulich
2011-03-24 8:56 ` Ingo Molnar
2011-03-24 14:52 ` Borislav Petkov
2011-03-24 16:48 ` Jan Beulich
2011-03-24 17:19 ` Ingo Molnar
2011-03-25 10:06 ` Jan Beulich
2011-03-25 11:10 ` Ingo Molnar
2011-03-25 12:04 ` Nikanth Karthikesan
2011-03-25 13:12 ` Jack Steiner
2011-03-25 16:29 ` Linus Torvalds
2011-03-25 16:47 ` Jan Beulich
2011-03-25 16:49 ` Jack Steiner
2011-03-24 17:30 ` Jack Steiner
2011-03-24 20:00 ` Ingo Molnar
2011-03-24 20:40 ` Andi Kleen
2011-03-24 20:50 ` Ingo Molnar
2011-03-24 21:37 ` Andi Kleen
2011-03-24 20:48 ` Eric Dumazet
2011-03-24 20:54 ` Ingo Molnar
2011-03-24 21:02 ` Eric Dumazet
2011-03-24 21:42 ` Andi Kleen
2011-03-24 23:26 ` Linus Torvalds
2011-03-24 23:56 ` Andi Kleen
2011-03-25 5:47 ` Eric Dumazet
2011-03-25 9:32 ` Ingo Molnar
2011-03-25 9:44 ` Eric Dumazet
2011-03-25 9:59 ` Ingo Molnar
2011-03-25 10:50 ` Borislav Petkov [this message]
2011-03-25 11:10 ` Peter Zijlstra
2011-03-25 11:11 ` Ingo Molnar
2011-03-25 16:16 ` Robert Richter
2011-03-25 17:22 ` Andi Kleen
2011-03-25 19:26 ` Ingo Molnar
2011-03-25 9:38 ` Eric Dumazet
2011-03-25 20:29 ` Peter Zijlstra
2011-03-26 8:15 ` Eric Dumazet
2011-03-26 9:44 ` Peter Zijlstra
2011-03-26 9:57 ` Ingo Molnar
2011-03-25 9:22 ` Ingo Molnar
2011-03-25 10:21 ` Peter Zijlstra
2011-03-25 16:08 ` Robert Richter
2011-03-25 19:31 ` Ingo Molnar
2011-03-25 17:15 ` Andi Kleen
2011-03-25 19:21 ` Ingo Molnar
2011-03-25 9:35 ` Ingo Molnar
2011-03-24 17:01 ` Linus Torvalds
2011-03-24 17:13 ` Jack Steiner
2011-03-24 18:38 ` Andi Kleen
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