From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25203 invoked by alias); 23 Sep 2008 18:29:06 -0000 Received: (qmail 25195 invoked by uid 22791); 23 Sep 2008 18:29:06 -0000 X-Spam-Status: No, hits=-3.0 required=5.0 tests=AWL,BAYES_00,J_CHICKENPOX_54,SARE_MSGID_LONG40,SPF_PASS X-Spam-Check-By: sourceware.org Received: from smtp-out.google.com (HELO smtp-out.google.com) (216.239.33.17) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 23 Sep 2008 18:28:26 +0000 Received: from spaceape7.eur.corp.google.com (spaceape7.eur.corp.google.com [172.28.16.141]) by smtp-out.google.com with ESMTP id m8NISKXL012894 for ; Tue, 23 Sep 2008 19:28:20 +0100 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=google.com; s=beta; t=1222194500; bh=MIKLELoDTIG/RFjBb7uAXCk5k/0=; h=DomainKey-Signature:Message-ID:Date:From:To:Subject:Cc: In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-Disposition:References:X-GMailtapped-By; b=HXn18+4rAtuLlVm 8biZCLAs4iM/2fuzLkfX3yTHq7MVHLK6U4m0r5M63jsnXgqzKAZIRcUIh217keJi1hF lNsw== DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=message-id:date:from:to:subject:cc:in-reply-to: mime-version:content-type:content-transfer-encoding: content-disposition:references:x-gmailtapped-by; b=wozlSZX3gtYmBG+dSvaAg1lk/4G8p4Gid6GrxNsEGhNlaqc6pisBWgoGc5M5flQJF 2qeomgKWAXaURSx1LwiTg== Received: from gxk8 (gxk8.prod.google.com [10.202.11.8]) by spaceape7.eur.corp.google.com with ESMTP id m8NIOZRI011236 for ; Tue, 23 Sep 2008 11:28:19 -0700 Received: by gxk8 with SMTP id 8so4622124gxk.14 for ; Tue, 23 Sep 2008 11:28:18 -0700 (PDT) Received: by 10.143.161.11 with SMTP id n11mr2120032wfo.333.1222194498074; Tue, 23 Sep 2008 11:28:18 -0700 (PDT) Received: by 10.142.49.3 with HTTP; Tue, 23 Sep 2008 11:28:17 -0700 (PDT) Message-ID: <33307c790809231128w44c79b8y40a821c2989f9b73@mail.gmail.com> Date: Tue, 23 Sep 2008 18:29:00 -0000 From: "Martin Bligh" To: "KOSAKI Motohiro" Subject: Re: Unified tracing buffer Cc: "Masami Hiramatsu" , "Linux Kernel Mailing List" , "Linus Torvalds" , "Thomas Gleixner" , "Mathieu Desnoyers" , "Steven Rostedt" , od@novell.com, "Frank Ch. Eigler" , systemtap-ml In-Reply-To: <20080924025457.DC24.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080923232239.DC1E.KOSAKI.MOTOHIRO@jp.fujitsu.com> <48D90970.3060409@redhat.com> <20080924025457.DC24.KOSAKI.MOTOHIRO@jp.fujitsu.com> X-GMailtapped-By: 172.28.16.141 Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2008-q3/txt/msg00777.txt.bz2 >> I think the main reason of using single-channel mode is simplicity of >> userspace reader. We can use 'cat' or 'tail' to read the buffer on-line. >> I'm not sure how much overhead ftrace-like buffer merging routine has, >> but if kernel provides an interface which gives us single-merged buffer >> image(like ftrace buffer), we are grad to use it. :-) > > Yup, I also think it is better. That was the plan, yes. Merge sort is cheap ;-)