From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arun Sharma <asharma@fb.com>
Subject: Re: [PATCH 1/4] perf, x86: Allow multiple stacks
Date: Mon, 7 May 2012 16:46:45 -0700
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Cc: Ingo Molnar <mingo@elte.hu>, Arnaldo Carvalho de Melo <acme@redhat.com>, Frederic Weisbecker <fweisbec@gmail.com>, Mike Galbraith <efault@gmx.de>, Paul Mackerras <paulus@samba.org>, Peter Zijlstra <peterz@infradead.org>, Stephane Eranian <eranian@google.com>, Namhyung Kim <namhyung.kim@lge.com>, Tom Zanussi <tzanussi@gmail.com>, linux-perf-users@vger.kernel.org

On 4/20/12 3:41 PM, Arun Sharma wrote:
> Without this patch, applications with two different stack
> regions (eg: native stack vs JIT stack) get truncated
> callchains even when RBP chaining is present. GDB shows proper
> stack traces and the frame pointer chaining is intact.
>
> This patch disables the (fp<  RSP) check, hoping that other checks
> in the code save the day for us. In our limited testing, this
> didn't seem to break anything.
>
> In the long term, we could potentially have userspace advise
> the kernel on the range of valid stack addresses, so we don't
> spend a lot of time unwinding from bogus addresses.

Ingo/Peter: Did you get a chance to look at this patch series (Support 
multiple stacks v3)?

  -Arun