[Top] [All Lists]

Re: "RT_PREEMPT for loongson" is updated to patch-

To: Zhang Le <>
Subject: Re: "RT_PREEMPT for loongson" is updated to patch-
From: Wu Zhangjin <>
Date: Mon, 20 Apr 2009 15:18:46 +0800
Cc:, Nicholas Mc Guire <>, Ingo Molnar <>, Thomas Gleixner <>,,,, Ralf Baechle <>,,
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; 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=/OuYhdX/QymCKziN5J1y+qWtbKUbzlCYkoST6LrmN2o=; b=adss4PXW/cUBYu2MbpLKMrMKp3TLGDMy02jSQR/f1UlCTK+z49iNzetoPrEA6T0t6u fBHz2X9w2Smrl5IaJHvC45vO7NKnL3z7IaMJXkrv4l6vH8iQosbIxE0TFgGUyugiE1kO UP/+9oVO0MwGBBbXva7yjRzAUP8CJLg+rgHjI=
Domainkey-signature: a=rsa-sha1; c=nofws;; 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=hEeoNltDuyOZb8GYEtd1Ya5Dii1F1Nq9vk0MBMvsu8AggTvB6W2mW6H/ikvkkLEQ5K 4L8XUmP6k60W8crtGkESLLl/LlN+1YBA8jWYiA/06NBV6Oh/6xSj4ggIDsriR3s2IzsH TtHf81LjPCxbgvtBLGMny+hqJNcUTwEDJdjlY=
In-reply-to: <>
Organization: DSLab, Lanzhou University, China
Original-recipient: rfc822;
References: <1240193547.25532.52.camel@falcon> <>
On Mon, 2009-04-20 at 13:04 +0800, Zhang Le wrote:
> Hi, Zhangjin,
> Ralf told me he has a ftrace implementation too.
> 11:47 < Ralf> r0bertz: ftrace looks nice but not yet mergable yet.
> 11:47 < Ralf> r0bertz: I also have my own ftrace implementation which in some
> parts is better, in some is worse. 
> 11:47 < Ralf> r0bertz: So this is going to be quite a job.  
> So I think you can talk to Ralf about how to get this merged, :)

to Zhangle, 

thx very much for your info :-) 

hope Ralf can reply this E-mail and pull the source code from my git


to Ralf, 

I have divided ftrace to several commits in the above git tree, hope you
can check it, thx :-) 

in addition to the static/dynamic/graph function tracer & system call
tracer implementation, a mips specific ring_buffer_time_stamp
(kernel/trace/ring_buffer.c) is also implemented to get 1us precision
time, this is very important to make ftrace available in mips,
otherwise, we can only get 1ms precision time for the original
ring_buffer_time_stamp is based on sched_clock(jiffies based). 

perhaps we can implement a more precise sched_clock directly, just as
x86 does(native_sched_clock, tsc based), but in mips, there is only a
32bit timer count which will quickly overflow, so it will need an extra
overflow protection, which may influence the other parts of the kernel.

best regards,
Wu Zhangjin

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