Re: [Valgrind-users] Counting instructions for specific part of my code using Callgrind

[Josef W. <Jos...@gm...>]

Am 31.08.2015 um 17:10 schrieb Florian Krohm:
> On 28.08.2015 09:03, Josef Weidendorfer wrote:
> 
>> This suggests we should document the difference between
>> START/STOP_INSTRUMENTAITON
>> and TOGGLE_COLLECT better. 
> 
> Hmm, yes :) Any chance you can write something up in time for 3.11 ?

This is about Section 6.2.2 "Limiting the range of collected events"
in the Callgrind part of Valgrind's manual.

I just rephrased this section. Can you check if this is clearer now?

It should also make clear why switching instrumentation mode often can
get very slow.

>> With macros in C, the compiler can reorder stuff, so you may end up with
>> something like
>
> Huh? CALLGRIND_START_INSTRUMENTATION expands into a statement sequence
> that includes
>    __asm__ volatile("whatever" ::: "memory");

Oops, I stay corrected.

Josef