lkml.org 
[lkml]   [2013]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 04/12] perf, x86: Support the TSX intx/intx_cp qualifiers v2
On Sat, Jan 26, 2013 at 12:54:02PM +0100, Ingo Molnar wrote:
>
> * Andi Kleen <andi@firstfloor.org> wrote:
>
> > From: Andi Kleen <ak@linux.intel.com>
> >
> > Implement the TSX transaction and checkpointed transaction
> > qualifiers for Haswell. This allows e.g. to profile the number
> > of cycles in transactions.
>
> The changelog should explain why this is a basic feature that is
> a must-have to have basic perf support. (i.e. default 'perf
> record', 'perf report', 'perf stat' and 'perf top' works and is
> meaningful.)

The patch is not needed for primitive cycle sampling only.

These qualifiers are a fundamental feature for any TSX tuning. If you don't
care about TSX it's not fundamental. TSX tuning relies heavily on the PMU,
so for any TSX work it's important. The 0/0 description has more
references on the topic.

It's not easy to use however with just this patch, the "perf stat -T" patch
in the advanced series makes it easy to use.

I will assume the description is sufficient and will not repost with
a new changelog, as "basicness" of the patch is not a useful property
to document in the long term git history.

-Andi
--
ak@linux.intel.com -- Speaking for myself only.


\
 
 \ /
  Last update: 2013-01-26 22:21    [W:0.062 / U:2.460 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site