From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758494AbaELOJO (ORCPT ); Mon, 12 May 2014 10:09:14 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.232]:61457 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758472AbaELOJL (ORCPT ); Mon, 12 May 2014 10:09:11 -0400 Date: Mon, 12 May 2014 10:09:08 -0400 From: Steven Rostedt To: Peter Zijlstra Cc: Dongsheng Yang , "yangds.fnst" , linux-kernel@vger.kernel.org, mingo@redhat.com, bsegall@google.com Subject: Re: [PATCH] sched: Distinguish sched_wakeup event when wake up a task which did schedule out or not. Message-ID: <20140512100908.07cc50bc@gandalf.local.home> In-Reply-To: <20140512064730.GI30445@twins.programming.kicks-ass.net> References: <53683B14.3060702@cn.fujitsu.com> <1399341154-11785-1-git-send-email-yangds.fnst@cn.fujitsu.com> <20140510152902.GW11096@twins.programming.kicks-ass.net> <536F90BE.2080806@gmail.com> <20140511163531.GG30445@twins.programming.kicks-ass.net> <20140511145224.00412e59@gandalf.local.home> <20140512064730.GI30445@twins.programming.kicks-ass.net> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.22; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.130:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 12 May 2014 08:47:30 +0200 Peter Zijlstra wrote: > But that has nothing what so fucking ever to do with 'success'. Reusing > that trace argument for something entirely different is just retarded. And having a "success" field that his hard coded to "true" is also retarded. At least this change is fucking useful. How about this. Add a new field called 'rq_added' or something. We can ever shrink the size of the "success" field and hard code it to true in the trace. That will never change. Then the caller of the tracepoint will send in a "true" or "false" to "rq_added" and we can add that tracepoint as well. What I mean by shrink the size of the success field is that it is currently 4 bytes in size. We can make it two (or one) and then add another field for the 'rq_added' and have that be two bytes as well. This shouldn't break any tools that use this. Point being, this is useful information, why not pass it to userspace? -- Steve