From: Travis Downs <travis.downs@gmail.com>
To: Milian Wolff <milian.wolff@kdab.com>
Cc: ak@linux.intel.com, jolsa@redhat.com,
linux-kernel@vger.kernel.org, jolsa@kernel.org,
namhyung@kernel.org, linux-perf-users@vger.kernel.org,
acme@kernel.org
Subject: Re: PEBS level 2/3 breaks dwarf unwinding! [WAS: Re: Broken dwarf unwinding - wrong stack pointer register value?]
Date: Wed, 14 Nov 2018 21:05:32 -0500 [thread overview]
Message-ID: <CAOBGo4wPeobp90eqZF1apZxHUn-dnh6L3Rpt_=beR49o3XHY7g@mail.gmail.com> (raw)
In-Reply-To: <31474933.dcNFsqGoRn@agathebauer>
On Wed, Nov 14, 2018 at 8:20 AM Milian Wolff <milian.wolff@kdab.com> wrote:
> 3) I suggest we always keep the first frame and sample IP from the user regs,
> i.e. the accurate PEBS/IBS IP. Then we add the following frames from unwinding
> the ustack with the iregs.
Does this mean that the displayed unwind will sometimes be
"impossible" to have actually be generated from a consistent execution
of the user program?
For example, the top frame (from PEBS) and second frame (from iregs)
may be inconsistent in that the latter function never calls the first.
At this point it would be good to have an indication at the top frame
is from a different source than the rest of the frames, lest the user
pull is hair out trying to determine how function X seems to call
function Y despite that not being the case in the source.
next prev parent reply other threads:[~2018-11-15 2:06 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-20 22:39 Broken dwarf unwinding - wrong stack pointer register value? Milian Wolff
2018-10-21 20:32 ` Milian Wolff
2018-10-22 10:35 ` Milian Wolff
2018-10-22 11:17 ` Milian Wolff
2018-10-22 13:58 ` Andi Kleen
2018-10-22 19:26 ` Milian Wolff
2018-10-23 4:03 ` Andi Kleen
2018-10-23 10:34 ` Milian Wolff
2018-10-24 14:48 ` Andi Kleen
2018-10-30 22:34 ` Milian Wolff
2018-11-01 22:08 ` PEBS level 2/3 breaks dwarf unwinding! [WAS: Re: Broken dwarf unwinding - wrong stack pointer register value?] Milian Wolff
2018-11-02 11:26 ` Jiri Olsa
2018-11-02 17:56 ` Milian Wolff
2018-11-05 20:51 ` Jiri Olsa
2018-11-05 22:54 ` Milian Wolff
2018-11-06 0:10 ` Andi Kleen
2018-11-06 8:39 ` Jiri Olsa
2018-11-06 17:26 ` Andi Kleen
2018-11-06 20:04 ` Milian Wolff
2018-11-06 20:24 ` Andi Kleen
2018-11-07 22:41 ` Milian Wolff
2018-11-08 12:41 ` Milian Wolff
2018-11-09 0:55 ` Andi Kleen
2018-11-09 0:54 ` Andi Kleen
2018-11-10 21:42 ` Travis Downs
2018-11-11 1:07 ` Andi Kleen
[not found] ` <CAOBGo4zirLiKX8VcROAE=kAD0+qkF0E-cBv9DtBiQr=_obDv5w@mail.gmail.com>
2018-11-11 2:54 ` Travis Downs
2018-11-12 3:26 ` Andi Kleen
2018-11-14 13:20 ` Milian Wolff
2018-11-15 2:05 ` Travis Downs [this message]
2018-11-15 9:10 ` Milian Wolff
2018-11-15 19:00 ` Andi Kleen
2018-11-15 2:15 ` Travis Downs
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