From: Andi Kleen <ak@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Venkatesh Srinivas <venkateshs@google.com>,
linux-kernel@vger.kernel.org, eranian@google.com, mingo@elte.hu,
zheng.z.yan@intel.com
Subject: Re: [PATCH] perf/x86/intel: Use rdmsrl_safe when initializing RAPL PMU.
Date: Fri, 14 Mar 2014 06:56:52 -0700 [thread overview]
Message-ID: <20140314135652.GE3793@tassilo.jf.intel.com> (raw)
In-Reply-To: <20140314084429.GO27965@twins.programming.kicks-ass.net>
On Fri, Mar 14, 2014 at 09:44:29AM +0100, Peter Zijlstra wrote:
> On Thu, Mar 13, 2014 at 12:36:26PM -0700, Venkatesh Srinivas wrote:
> > CPUs which should support the RAPL counters according to
> > Family/Model/Stepping may still issue #GP when attempting to access
> > the RAPL MSRs. This may happen when Linux is running under KVM and
> > we are passing-through host F/M/S data, for example. Use rdmsrl_safe
> > to first access the RAPL_POWER_UNIT MSR; if this fails, do not
> > attempt to use this PMU.
>
> This kvm thing is getting tedious :-(
It sounds bogus to me too, VMs are supposed to return 0
on reading unknown MSRs, no #GP.
-Andi
--
ak@linux.intel.com -- Speaking for myself only
next prev parent reply other threads:[~2014-03-14 13:56 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-13 19:36 [PATCH] perf/x86/intel: Use rdmsrl_safe when initializing RAPL PMU Venkatesh Srinivas
2014-03-14 8:44 ` Peter Zijlstra
2014-03-14 13:56 ` Andi Kleen [this message]
2014-03-14 15:21 ` Venkatesh Srinivas
2014-03-14 16:17 ` Andi Kleen
2014-03-14 16:57 ` David Ahern
2014-03-14 23:07 ` Venkatesh Srinivas
2014-04-18 13:08 ` [tip:perf/core] perf/x86/intel: Use rdmsrl_safe() " tip-bot for Venkatesh Srinivas
2014-04-23 14:31 ` [PATCH] perf/x86/intel: Use rdmsrl_safe " Stephane Eranian
2014-04-23 14:45 ` Peter Zijlstra
2014-04-23 14:49 ` Stephane Eranian
2014-04-23 15:09 ` Peter Zijlstra
2014-04-23 15:14 ` Stephane Eranian
2014-04-23 15:16 ` Borislav Petkov
2014-04-23 15:18 ` Stephane Eranian
2014-04-23 15:35 ` Borislav Petkov
2014-04-23 15:44 ` Stephane Eranian
2014-04-23 15:55 ` Borislav Petkov
-- strict thread matches above, loose matches on Subject: below --
2014-03-07 4:42 Venkatesh Srinivas
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