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From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
To: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
	James Bottomley <James.Bottomley@suse.de>,
	Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Paul Mackerras <paulus@samba.org>,
	"Frank Ch. Eigler" <fche@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] x86: record relocation offset
Date: Thu, 31 Dec 2009 11:00:00 +0800	[thread overview]
Message-ID: <4B3C13B0.6080600@cn.fujitsu.com> (raw)
In-Reply-To: <20091231003046.GC2384@ghostprotocols.net>



Arnaldo Carvalho de Melo wrote:

> 
> Conclusion: at 'perf record' time store the address of a well know
> symbol (_text) into the perf.data header. Later, at perf report time, if
> using a vmlinux file, calculate the relocation by subtracting the same
> well known symbol from the one stored in the header.
> 
> So no need for ioctl or boot stuff.
> 

I'm little confused, how to get the load symbol address?
It's not a good way, if you get it from '/proc/kallsyms', we can't assume kernel
has this file.

> I'll do that tomorrow, if Xiao doesn't beats me to it :-)
> 

Of course, please do if you have a better way :-)

Thanks,
Xiao

  reply	other threads:[~2009-12-31  3:01 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-30 23:26 [PATCH 1/3] x86: record relocation offset H. Peter Anvin
2009-12-30 23:41 ` James Bottomley
2009-12-30 23:46   ` H. Peter Anvin
2009-12-31  0:30     ` Arnaldo Carvalho de Melo
2009-12-31  3:00       ` Xiao Guangrong [this message]
2009-12-31 10:36         ` Arnaldo Carvalho de Melo
2009-12-31 10:50           ` Xiao Guangrong
2010-01-01  9:27           ` Ingo Molnar
2009-12-31  2:58     ` Xiao Guangrong
2009-12-31  0:53   ` Frank Ch. Eigler
  -- strict thread matches above, loose matches on Subject: below --
2009-12-30 22:09 H. Peter Anvin
2009-12-30  3:15 [PATCH 0/3] perf_event: fix getting symbol error if kernel is relocatable Xiao Guangrong
2009-12-30  3:16 ` [PATCH 1/3] x86: record relocation offset Xiao Guangrong
2009-12-30 13:15   ` Arnaldo Carvalho de Melo
2009-12-30 19:45     ` H. Peter Anvin
2009-12-30 20:39       ` Arnaldo Carvalho de Melo
2009-12-30 21:58         ` Arnaldo Carvalho de Melo
2009-12-30 22:22           ` James Bottomley

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