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 28CA2C433FE for ; Tue, 1 Mar 2022 20:18:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237845AbiCAUSl (ORCPT ); Tue, 1 Mar 2022 15:18:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238336AbiCAUSe (ORCPT ); Tue, 1 Mar 2022 15:18:34 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D0FB37024; Tue, 1 Mar 2022 12:17:51 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id BD457B81D1D; Tue, 1 Mar 2022 20:17:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 69D77C340F1; Tue, 1 Mar 2022 20:17:46 +0000 (UTC) Date: Tue, 1 Mar 2022 15:17:44 -0500 From: Steven Rostedt To: Jithu Joseph Cc: hdegoede@redhat.com, markgross@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, corbet@lwn.net, gregkh@linuxfoundation.org, andriy.shevchenko@linux.intel.com, ashok.raj@intel.com, tony.luck@intel.com, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, platform-driver-x86@vger.kernel.org, patches@lists.linux.dev, ravi.v.shankar@intel.com Subject: Re: [RFC 10/10] trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations Message-ID: <20220301151744.1ad5e11a@gandalf.local.home> In-Reply-To: <20220301195457.21152-11-jithu.joseph@intel.com> References: <20220301195457.21152-1-jithu.joseph@intel.com> <20220301195457.21152-11-jithu.joseph@intel.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Tue, 1 Mar 2022 11:54:57 -0800 Jithu Joseph wrote: > + TP_STRUCT__entry( > + __field( u8, start ) > + __field( u8, stop ) > + __field( u64, status ) > + ), I'd suggest swapping this to: __field( u64, status ) __field( u8, start ) __field( u8, stop ) As trace events are usually aligned by 4 bytes (sometimes 8 for archs that require 8byte alignment for 8 byte words), but any event, putting the padding at the end of the event is better than in the middle of the event. Having the u64 come after two u8 (two byes) will pretty much guarantee a 6 bytes hole in the middle of the event. -- Steve