Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [RFC] Add --show-total-period for perf annotate | Date | Fri, 22 May 2015 21:08:38 -0700 |
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Martin Liška <mliska@suse.cz> writes:
> I've been working on a new feature for perf annotate, which should be able to annotate > instructions with total spent time (compared to percentage usage). > > Let's consider following use-case. You want to compare two different compilers > on the same code base and let's assume 90% of wall-time is spent in a single function. > Moreover, let's say that these compilers produce assembly of a totally different size. > > In such case, it's very useful to get an approximation of spent time on a bunch of instructions, > which can be compared among other compilers. Otherwise, one has to somehow sum percentages and compare > it to size of a function.
perf diff does not handle this? Especially with the differential profiling options it should.
>> @@ -623,6 +624,8 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) > if (!target__none(&opts->target) && !opts->initial_delay) > perf_evlist__enable(rec->evlist); > > + t0 = rdclock(); > + > /* > * Let the child rip > */ > @@ -692,6 +695,9 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) > goto out_child; > } > > + t1 = rdclock(); > + walltime_nsecs = t1 - t0;
The walltime can be later computed by the difference of the first and the last time stamp after sorting the events. So you don't need the new header.
-Andi
-- ak@linux.intel.com -- Speaking for myself only
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