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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51873C0015E for ; Tue, 1 Aug 2023 11:47:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234378AbjHALrS (ORCPT ); Tue, 1 Aug 2023 07:47:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234369AbjHALrQ (ORCPT ); Tue, 1 Aug 2023 07:47:16 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F0A71712; Tue, 1 Aug 2023 04:47:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=TdpPIvgN+cdaHFVUOeW5qe3U6jUZBrGZ60UhJBXmvpY=; b=nlMuLsMdUfdbuRxXz8ioQYr9dR o686TG0N5P3FFJm71RgPXPuXuyi5MGCmJAwWjvWWD1FGfOVZghopNFrXVMrGwmCltAbzFaEPUjz67 +bYTPHB8bqmpL17ba+a4/SToPkoEqTYC06G6LWtHg7RqwZbkDfAFypL/pDqf6zpIdc3l997qe2lYk F0PcYe0qRh4M0IsAHqoBm0KuTPdMbvaxxlfjXkMhxyizUyV5yVdvP+Rb6keTanahrL+cMkhP9gA+o reZfMTOT1G8UYsSshlsOnnC36pK5Q7ZKpVzTiP5oLC2H+MK0ytmlEIBGpfi67VDUB+P3jejVM1fMR +ZjaBQoA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qQnpz-00Edek-29; Tue, 01 Aug 2023 11:46:51 +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 (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 07920300134; Tue, 1 Aug 2023 13:46:51 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id ED4EF200C570F; Tue, 1 Aug 2023 13:46:50 +0200 (CEST) Date: Tue, 1 Aug 2023 13:46:50 +0200 From: Peter Zijlstra To: Ze Gao Cc: Adrian Hunter , Alexander Shishkin , Arnaldo Carvalho de Melo , Ian Rogers , Ingo Molnar , Jiri Olsa , Mark Rutland , Masami Hiramatsu , Namhyung Kim , Steven Rostedt , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-trace-devel@vger.kernel.org, Ze Gao Subject: Re: [RFC PATCH v3 4/6] sched, tracing: reorganize fields of switch event struct Message-ID: <20230801114650.GE79828@hirez.programming.kicks-ass.net> References: <20230801090124.8050-1-zegao@tencent.com> <20230801090124.8050-5-zegao@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230801090124.8050-5-zegao@tencent.com> Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org On Tue, Aug 01, 2023 at 05:01:22PM +0800, Ze Gao wrote: > Report priorities in 'short' and prev_state in 'int' to save > some buffer space. And also reorder the fields so that we take > struct alignment into consideration to make the record compact. > > Suggested-by: Steven Rostedt (Google) I don't see a single line describing the effort you've done to audit consumers of this tracepoint. *IF* you're wanting to break this tracepoint ABI, because seriously that's what it is, then you get to invest the time and effort to audit the users.