Messages in this thread | | | Date | Sun, 23 Nov 2008 22:38:55 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH 4/4] trace: profile all if conditionals |
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* 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
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