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From:   Joel Fernandes <joel@joelfernandes.org>
Date:   Fri, 1 Jul 2022 12:53:17 -0400
Message-ID: <CAEXW_YQk44VdSrZFtpfyCPHcrDxEFaEe2Wu900CZcWWodw3+xg@mail.gmail.com>
Subject: Re: [RFC PATCH 0/7] Trace events to pstore
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Nachammai Karuppiah <nachukannan@gmail.com>,
        Ingo Molnar <mingo@redhat.com>,
        Frank Rowand <frowand.list@gmail.com>,
        Kees Cook <keescook@chromium.org>,
        Anton Vorontsov <anton@enomsg.org>,
        Colin Cross <ccross@android.com>,
        Tony Luck <tony.luck@intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
        Brian Norris <computersforpeace@gmail.com>
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On Fri, Jul 1, 2022 at 12:46 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Fri, 1 Jul 2022 12:37:35 -0400
> Joel Fernandes <joel@joelfernandes.org> wrote:
>
> > I am curious how this came on your radar after 2 years, did someone
> > tell you to prioritize improving performance of ftrace on pstore? I
> > could probably make time to work on it more if someone has a usecase
> > for this or something.
>
> I'm looking into ways to extract the ftrace ring buffer from crashes, and
> it was brought up that pstore was used before.

Interesting. In the case of pstore, you know exactly where the pages
are for ftrace. How would you know that for the buddy system where
pages are in the wild wild west? I guess you would need to track where
ftrace pages where allocated, within the crash dump/report.

 - Joel