Re: [tip:perf/urgent] perf/x86/intel: Initialize TFA MSR

From: Vince Weaver
Date: Wed Apr 03 2019 - 08:24:02 EST


On Wed, 3 Apr 2019, Thomas Gleixner wrote:

> On Wed, 3 Apr 2019, tip-bot for Peter Zijlstra wrote:
>
> > Commit-ID: d7262457e35dbe239659e62654e56f8ddb814bed
> > Gitweb: https://git.kernel.org/tip/d7262457e35dbe239659e62654e56f8ddb814bed
> > Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > AuthorDate: Thu, 21 Mar 2019 13:38:49 +0100
> > Committer: Ingo Molnar <mingo@xxxxxxxxxx>
> > CommitDate: Wed, 3 Apr 2019 11:40:32 +0200
> >
> > perf/x86/intel: Initialize TFA MSR
> >
> > Stephane reported that the TFA MSR is not initialized by the kernel,
> > but the TFA bit could set by firmware or as a leftover from a kexec,
> > which makes the state inconsistent.
> >
> > Reported-by: Stephane Eranian <eranian@xxxxxxxxxx>
> > Tested-by: Nelson DSouza <nelson.dsouza@xxxxxxxxx>
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> > Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
> > Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
> > Cc: tonyj@xxxxxxxx
> > Link: https://lkml.kernel.org/r/20190321123849.GN6521@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
>
> This lacks:
>
> 1) Fixes tag
>
> 2) Cc: stable ....
>
> Sigh.

It would also be nice to know what a "TFA" bit is without having to go
find a copy of the Intel documentation.

Vince