Re: [RFC] perf record: Disable debuginfod by default

[Namhyung Kim <namhyung@kernel.org>]

On Fri, Dec 10, 2021 at 4:23 AM Jiri Olsa <jolsa@redhat.com> wrote:
>
> On Thu, Dec 09, 2021 at 03:39:20PM -0800, Namhyung Kim wrote:
> > Hi Jiri,
> >
> > On Thu, Dec 9, 2021 at 12:04 PM Jiri Olsa <jolsa@redhat.com> wrote:
> > >
> > > hi,
> > > after migrating to fedora 35 I found perf record hanging on exit
> > > and it's because fedora 35 sets DEBUGINFOD_URLS that triggers
> > > debuginfod query which might take long time to process.
> > >
> > > I discussed this briefly with Frank and I'm sending the change
> > > to disable debuginfod by default in perf record.
> > >
> > > Frank had other idea we could discuss here to fork or just spawn
> > > "/usr/bin/debuginfod-find ...." into background after perf record.
> > >
> > > Perhaps there are other ways as well, hence this is RFC ;-)
> >
> > I thought the debuginfod was for perf report, not record.
> > Maybe I'm missing something but how about moving it to
> > report?  We can talk to debuginfod after checking the local
> > build-id cache and binary on the system.
>
> at the end of the perf record we populate buildid cache
> with profiled binaries for the current perf.data
>
> **IF** there's DEBUGINFOD_URLS defined, that code will
> also ask debuginfod for binaries it could not find on
> the system

Yeah, I know what you're doing.  But I guess debuginfod
contains binaries for the distro and they'd be available for
a while.  Then I think we don't need to do it at perf record.

Thanks,
Namhyung