lkml.org 
[lkml]   [2008]   [Nov]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 4/4] trace: profile all if conditionals

* Steven Rostedt <rostedt@goodmis.org> wrote:

> On Sun, 23 Nov 2008, Andi Kleen wrote:
> > Steven Rostedt <rostedt@goodmis.org> writes:
>
> > > This adds a significant amount of overhead and should only be
> > > used by those analyzing their system.
> >
> > Often this can be also done using CPU performance counters. Might
> > be a cheaper option.
>
> I'd love to add an option that could hook into any arch with HW
> support for this. We could dump out the same information, but just a
> different way to gather it. But I'm still ignorant to the use of
> CPU performance counters and how to find which branch matches which
> if.

there's already new ftrace code for this and the patches are done -
stay tuned.

but it wont be a replacement for the soft method (which is more
flexible - the hw can only do 'all or nothing' type of branch
tracing), so it's complementary.

Ingo


\
 
 \ /
  Last update: 2008-11-23 22:43    [W:0.056 / U:0.496 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site