linux-mips
[Top] [All Lists]

Re: [PATCH -v6 07/13] tracing: add dynamic function tracer support for M

To: rostedt@goodmis.org
Subject: Re: [PATCH -v6 07/13] tracing: add dynamic function tracer support for MIPS
From: Wu Zhangjin <wuzhangjin@gmail.com>
Date: Tue, 27 Oct 2009 01:35:40 +0800
Cc: linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, Frederic Weisbecker <fweisbec@gmail.com>, Thomas Gleixner <tglx@linutronix.de>, Ralf Baechle <ralf@linux-mips.org>, Richard Sandiford <rdsandiford@googlemail.com>, Nicholas Mc Guire <der.herr@hofr.at>, David Daney <ddaney@caviumnetworks.com>, Adam Nemet <anemet@caviumnetworks.com>, Patrik Kluba <kpajko79@gmail.com>
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:subject:from:reply-to:to:cc :in-reply-to:references:content-type:organization:date:message-id :mime-version:x-mailer:content-transfer-encoding; bh=r/4VZj+WUR45B6+ps4g6i9wf9PQJ5nBKxgTVgR3SPjw=; b=nDa71eMJAMQGNcVdZNutUoMjePRBWXrETmfKW/MVXXCA/feLVYkBmyVFm+ErK342vw 3r6K5N40NkiczyN2xyd9QZjOnSVNGVOCi47YOb3VpBS+UWuBB1pC4JFJCnPuxeLUnIYq G5m7gA21y8P61zQhQw1/On1/cGg+hDYqSBSSc=
Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:reply-to:to:cc:in-reply-to:references:content-type :organization:date:message-id:mime-version:x-mailer :content-transfer-encoding; b=XfiFLDWD5k/6PeKeJZBGq649GcUthkDvCdB3UUTz4fM3NNwsgyesL+S6f3vM3vIZRH 2tD36jQcAGvXBcC9YeGpJnFDff5CI1k9ZcWSJY/4Hg/stdk72fRiU9kGvt6tVFYA5KMS s3C4EM/u9u1/JrR1S/o1nwk2k7Qt8OQYgO2sI=
In-reply-to: <1256575500.26028.323.camel@gandalf.stny.rr.com>
Organization: DSLab, Lanzhou University, China
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <cover.1256569489.git.wuzhangjin@gmail.com> <747deea2f18d5ccffe842df95a9dd1c86251a958.1256569489.git.wuzhangjin@gmail.com> <3f47087b70a965fd679b17a59521671296457df1.1256569489.git.wuzhangjin@gmail.com> <f290e125634d164ec65b09b24b269815f78455ab.1256569489.git.wuzhangjin@gmail.com> <07dc907ec62353b1aca99b2850d3b2e4b734189a.1256569489.git.wuzhangjin@gmail.com> <374da7039d2e1b97083edd8bcd7811356884d427.1256569489.git.wuzhangjin@gmail.com> <3c82af564d70be05b92687949ed134ce034bf8db.1256569489.git.wuzhangjin@gmail.com> <a11775df0ec9665fab5861f4fa63a3e192b9ffec.1256569489.git.wuzhangjin@gmail.com> <1256573175.26028.310.camel@gandalf.stny.rr.com> <1256574910.5642.228.camel@falcon> <1256575500.26028.323.camel@gandalf.stny.rr.com>
Reply-to: wuzhangjin@gmail.com
Sender: linux-mips-bounce@linux-mips.org
On Mon, 2009-10-26 at 12:45 -0400, Steven Rostedt wrote:
> On Tue, 2009-10-27 at 00:35 +0800, Wu Zhangjin wrote:
> 
> > If remove the long jump, we at least to change the $mcount_regex in
> > scripts/recordmcount.pl, the addr + 12 in arch/mips/include/asm/ftrace.h
> > and the _mcount & ftrace_caller in mcount.S and the ftrace_make_nop &
> > ftrace_make_call in arch/mips/kernel/ftrace.c back to the -v4 version.
> > 
> > I think this method of supporting module is not that BAD, no obvious
> > overhead added except the "lui...addiu..." and two more "nop"
> > instructions. and it's very understandable, so, just use this version?
> 
> You don't nop the lui and addiu do you? If you do you will crash the
> machine.

Not test it yet, Seems what you have mentioned in another thread:

b  1f
....
1:

is a good idea, it will only left one "lui" and one "b 1f" instruction
there.

(I'm sleepy now, the time is Tue Oct 27 01:34:51 CST 2009 in China, See
you~~)

Regards,
        Wu Zhangjin


<Prev in Thread] Current Thread [Next in Thread>