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Date:   Wed, 16 Jan 2019 13:37:35 +0900
From:   Namhyung Kim <namhyung@kernel.org>
To:     Arnaldo Carvalho de Melo <acme@kernel.org>
Cc:     Nick Clifton <nickc@redhat.com>, Jiri Olsa <jolsa@kernel.org>,
        lkml <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Michael Petlan <mpetlan@redhat.com>,
        Masami Hiramatsu <mhiramat@kernel.org>, kernel-team@lge.com
Subject: Re: [RFC] perf tools: Filter out hidden symbols from labels
Message-ID: <20190116043735.GA31070@sejong>
References: <20190115135354.11572-1-jolsa@kernel.org>
 <960f0b83-a623-67a6-ab55-d56139d10ba2@redhat.com>
 <20190115163540.GA20159@kernel.org>
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Hi,

On Tue, Jan 15, 2019 at 01:35:40PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Tue, Jan 15, 2019 at 04:13:16PM +0000, Nick Clifton escreveu:
> > Hi Jiri,
> > 
> > > When perf is built with annobin plugin (RHEL8 build) extra symbols
> > > are added to its binary:
> > 
> >   A bit of background for those wondering why annobin is creating
> >   these symbols:  Annobin is a plugin for gcc that records data 
> >   about how object file were built.  It is specifically designed 
> >   to be able to cope with files that are built using multiple
> >   different sets of optimization options.  (Eg because of #pragma
> >   directives or function specific optimization attributes).  It
> >   generates notes to cover each compiled region of code, and it
> >   needs the symbols in order to be able to determine exactly which
> >   areas in a linked binary were compiled with which options.
> 
> Humm, it would be nice for perf annotate to show those options when one
> navigates the annotation, something like press some hotkey and see the
> optimization flags used. Is there any library that gets those
> annotations and put them in some linked list that we could use in
> tools/perf/?

If it's just an ELF note, we could parse it directly.

https://developers.redhat.com/blog/2018/02/20/annobin-storing-information-binaries/

Thanks,
Namhyung