Re: [PATCH] perf dso: Fix dso comparison

From: Jiri Olsa
Date: Tue Mar 24 2020 - 09:30:23 EST


On Tue, Mar 24, 2020 at 06:07:23PM +0530, Ravi Bangoria wrote:

SNIP

> > looks good, do we need to add the dso_id check to sort__dso_cmp?
>
> I guess with different filename there is no need to compare dso_id.
> But for same filename, adding dso_id cmp will separate out the
> samples:
>
> Ex, Without dso_id compare:
>
> $ ./perf report -s dso,dso_size -v
> 66.63% /home/ravi/a.out 4096
> 33.36% /home/ravi/Workspace/linux/tools/perf/a.out 4096
>
> $ ./perf report -s dso,dso_size
> 99.99% a.out 4096
>
>
> With below diff:
>
> - return strcmp(dso_name_l, dso_name_r);
> + ret = strcmp(dso_name_l, dso_name_r);
> + if (ret)
> + return ret;
> + else
> + return dso__cmp_id(dso_l, dso_r);
>
>
> $ ./perf report -s dso,dso_size
> 99.99% a.out 4096
> 33.36% a.out 4096
>
> though, the o/p also depends which other sort keys are used along
> with dso key. Do you think this change makes sense?

the above behaviour is something I'd expect from 'dso'
sort key to do - separate out different dsos, even with
the same name

jirka