Messages in this thread | | | From | Arnaldo Carvalho de Melo <> | Date | Tue, 24 Mar 2020 10:42:07 -0300 | Subject | Re: [PATCH] perf dso: Fix dso comparison |
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Em Tue, Mar 24, 2020 at 02:22:58PM +0100, Jiri Olsa escreveu: > 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
This specific one can be resolved using -v when long_name will be used, the biggest problem is when long_name is the same (and thus short_name), which can happen when developing some software, i.e. compile+rebuild and get a different content, same short/long name, in that case we should use some diferentiator, the build-id comes to mind, but one that could be more useful would be file timestamp, meaning, hey, the older version is actually better, which one, lemme look at the build-id, and even the source code if developed with -g, by using the copy we stored in the build-id cache (~/.debug), which would be really useful workflow.
- Arnaldo
> jirka >
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- Arnaldo
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