From: jamie@jamieiles.com (Jamie Iles)
To: linux-arm-kernel@lists.infradead.org
Subject: [Questions] How to run 'perf top' on ARM to profile kernel functions with modules loaded
Date: Thu, 11 Nov 2010 09:17:34 +0000 [thread overview]
Message-ID: <20101111091733.GA2929@pulham.picochip.com> (raw)
In-Reply-To: <AANLkTim+BAYKWqiJzSQQLc4e_yNkMsNNnEp5u8YgC2Fk@mail.gmail.com>
On Thu, Nov 11, 2010 at 03:52:07PM +0800, Ming Lei wrote:
> 2010/11/11 Ming Lei <tom.leiming@gmail.com>:
> > Hi,
> >
> > 'perf top' can't display any functions when modules are loaded on ARM.
>
> Sorry, should be can't display any kernel functions when modules are loaded
> on ARM.
I've noticed this myself and I spent a bit of time looking into it last week
but didn't get too far. I did wonder if it was something to do with the map
fixups after loading the modules. If you look at the raw events after a perf
record with 'perf report -D' then the last module has a size that takes it to
0xFFFFFFFF which overlaps with the rest of the kernel symbols.
On x86 it looks like the modules are loaded after the kernel image in VM
unlike ARM.
Jamie
next prev parent reply other threads:[~2010-11-11 9:17 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-11 6:56 [Questions] How to run 'perf top' on ARM to profile kernel functions with modules loaded Ming Lei
2010-11-11 7:52 ` Ming Lei
2010-11-11 8:28 ` Ingo Molnar
2010-11-11 8:34 ` Kyungmin Park
2010-11-11 10:03 ` Ming Lei
2010-11-11 9:17 ` Jamie Iles [this message]
2010-11-11 12:06 ` Peter Zijlstra
2010-11-11 12:21 ` Jamie Iles
2010-11-11 12:30 ` Peter Zijlstra
2010-11-12 1:40 ` Ming Lei
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