From: fche@redhat.com (Frank Ch. Eigler)
To: Yale Zhang <yzhang1985@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>, linux-perf-users@vger.kernel.org
Subject: Re: Size of perf data files
Date: Thu, 08 Jan 2015 21:06:37 -0500 [thread overview]
Message-ID: <y0mlhlcemhe.fsf@fche.csb> (raw)
In-Reply-To: <CALQF7ZzpLB3Ch3=nn5yi23eneqwXnEpFTq6dX4BT7dLYvxcVXw@mail.gmail.com> (Yale Zhang's message of "Tue, 6 Jan 2015 13:02:23 -0800")
Yale Zhang <yzhang1985@gmail.com> writes:
> [...]
> I've already tried lowering the size of each sample from 8KiB to 512,
> but that only allows storing 2 or 3 parent function calls, which isn't
> enough for me.
>
> "don't use dwarf unwinding."
> The main reason I'm trying to switch from Zoom to perf is because it
> supports dwarf unwinding! [...]
You may wish to try systemtap. Its backtracing uses in-situ dwarf
unwinding, and is pretty fast. Each sample costs not 4K+ of stack
snapshots, but a hexadecimal pc-list or optionally symbolic backtrace
string. The downside is that the programs that you may be backtracing
need to be identified at stap invocation - ahead of time - via
something like:
% stap -d /bin/foo -d /usr/lib64/libbar.so --ldd --all-modules SCRIPT.stp
See e.g. https://sourceware.org/systemtap/examples/#profiling/pf4.stp
- FChE
next prev parent reply other threads:[~2015-01-09 2:08 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-06 3:21 Size of perf data files Yale Zhang
2015-01-06 5:39 ` Andi Kleen
2015-01-06 21:02 ` Yale Zhang
2015-01-06 21:29 ` Andi Kleen
2015-01-09 2:06 ` Frank Ch. Eigler [this message]
-- strict thread matches above, loose matches on Subject: below --
2014-11-26 12:47 Milian Wolff
2014-11-26 16:06 ` Arnaldo Carvalho de Melo
2014-11-26 18:11 ` Milian Wolff
2014-11-27 0:56 ` Namhyung Kim
2014-11-27 13:19 ` Arnaldo Carvalho de Melo
2014-11-28 6:18 ` Namhyung Kim
2014-11-26 20:48 ` Andi Kleen
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