From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pradyumna Sampath Subject: Re: Newbie question about profiling. Date: Thu, 23 Sep 2010 16:58:52 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-rt-users@vger.kernel.org To: Lars Segerlund Return-path: Received: from mail-qw0-f46.google.com ([209.85.216.46]:50372 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753436Ab0IWO6x convert rfc822-to-8bit (ORCPT ); Thu, 23 Sep 2010 10:58:53 -0400 Received: by qwh6 with SMTP id 6so1187343qwh.19 for ; Thu, 23 Sep 2010 07:58:52 -0700 (PDT) In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hi Lars, On Thu, Sep 23, 2010 at 4:42 PM, Lars Segerlund wrote: > =A0I was thinking that if I could create a realtime task to test for = a > specific thing, I really would like a log of what the kernal was doin= g > right before this. > =A0The only way I can think of is creating a module with a ring buffe= r ( > spill over ), and tracing the scheduler or interrupt handler .... ( b= y > hack=EDng some code to specifically do this ), this would only add a > small overhead AFAIK. > > =A0Any idea's anyone ? or hints ? > > =A0It seem's like just the thing that already might have a solution i= n > place, so I figured I should not reinvent the wheel. Yeah in the last couple of years a lot of tools have been developed to do exaclty this kind of thing. You could look for .. - FTrace https://rt.wiki.kernel.org/index.php/Ftrace - Tuna - LTTng =2E. Im sure there are a couple more but Ive used ftrace and LTTng and they are pretty cool. best regards /prady --=20 http://www.prady.in -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html