From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 970E5C433B4 for ; Mon, 26 Apr 2021 08:10:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62FB161090 for ; Mon, 26 Apr 2021 08:10:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232470AbhDZIL2 (ORCPT ); Mon, 26 Apr 2021 04:11:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232158AbhDZILG (ORCPT ); Mon, 26 Apr 2021 04:11:06 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8BB7C061574 for ; Mon, 26 Apr 2021 01:10:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=54e8KxTlMxMNItn0tucnFhc4T1kLMt7mf/+cwXF6rQg=; b=lv9+6O7hiCWac6G54xjYSCCb7t hdEq/UVSvFYaL5NMavLSqLYCm61jY8vqpeBQ0A6OMaGTiFLk384RkO/pN0Gfsgvga0p0d0arXYIPD sWkkOgPz9zIiouzvyyKmcMTJL8tmw//dK9CHi1ckVWfk/dMgKBUHqSu8YK9DhBcU/NJSxZYILExXp hQhXLRCwvxfy/0wFd+GE+T9Bn94kO92f2rTzqA5qbjSnZz3g6M63FK2ShClAlRha+e6G77dKGXxpn qedZxMxoHSEqlId5I2XA68FwSajufOujJZiHgoQ2WEW4i9Mf0If++PKgONN15d/6t3GHOb29UhWvh mgM4yzKA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lawJP-005Lvz-MP; Mon, 26 Apr 2021 08:09:52 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 5F1A0300212; Mon, 26 Apr 2021 10:09:47 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 100FD2C988F39; Mon, 26 Apr 2021 10:09:47 +0200 (CEST) Date: Mon, 26 Apr 2021 10:09:47 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: Ed Tsai , mingo@redhat.com, linux-kernel@vger.kernel.org, stanley.chu@mediatek.com, loda.chou@mediatek.com Subject: Re: [PATCH 1/1] sched: remove the redundant 'success' in the sched tracepoint Message-ID: References: <20210422122226.9415-1-ed.tsai@mediatek.com> <20210422114629.2b1ea3ad@gandalf.local.home> <0fd8e103cc2886724979f7d93066b86b773032eb.camel@mediatek.com> <20210425175426.23f292a9@oasis.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210425175426.23f292a9@oasis.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 25, 2021 at 05:54:26PM -0400, Steven Rostedt wrote: > On Fri, 23 Apr 2021 08:38:22 +0800 > Ed Tsai wrote: > > > On Thu, 2021-04-22 at 11:46 -0400, Steven Rostedt wrote: > > > On Thu, 22 Apr 2021 20:22:26 +0800 > > > Ed Tsai wrote: > > > > > > > 'success' is left here for a long time and also it is meaningless > > > > for the upper user. Just remove it. > > > > > > Have you tested all userspace code that might use this? > > > > > > This is the "poster boy" example of why Peter Zijlstra hates trace > > > events ;-) > > > > > > I know I've updated trace-cmd to check to see if this field exits > > > before > > > depending on it, but there may be some other tools that may not. > > > Perhaps > > > nothing will break. > > > > > > I'm all for this change, but be ware, it might be reverted if there's > > > some > > > tool out that that expects it to exist. This is why it hasn't been > > > removed. > > > > > > -- Steve > > > > It is left here over 5 years. Old userspace code need this entry and > > also someone may use it for a new tool. I hate this but it is a problem > > should be resolved for the kernel or ignore just fine. > > > > I'm willing to take this, with a note that if anyone complains, it may > be reverted. But as it goes with Linus's rule about breaking user > space. If you break user space, and nobody notices, you didn't really > break it! LatencyTop was I think the offender at the time, but I can't really remember. Anyway, glad to be rid of it, if we get away with it that is ;-)