Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935745AbcKWUNc (ORCPT ); Wed, 23 Nov 2016 15:13:32 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:59980 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935654AbcKWUNa (ORCPT ); Wed, 23 Nov 2016 15:13:30 -0500 Date: Wed, 23 Nov 2016 21:13:17 +0100 From: Peter Zijlstra To: kan.liang@intel.com Cc: mingo@redhat.com, acme@kernel.org, linux-kernel@vger.kernel.org, alexander.shishkin@linux.intel.com, tglx@linutronix.de, namhyung@kernel.org, jolsa@kernel.org, adrian.hunter@intel.com, wangnan0@huawei.com, mark.rutland@arm.com, andi@firstfloor.org Subject: Re: [PATCH 01/14] perf/x86: Introduce PERF_RECORD_OVERHEAD Message-ID: <20161123201317.GB3092@twins.programming.kicks-ass.net> References: <1479894292-16277-1-git-send-email-kan.liang@intel.com> <1479894292-16277-2-git-send-email-kan.liang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1479894292-16277-2-git-send-email-kan.liang@intel.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 514 Lines: 18 On Wed, Nov 23, 2016 at 04:44:39AM -0500, kan.liang@intel.com wrote: > +/* > + * single overhead record layout: > + * > + * cpu: The cpu which overhead occues This is duplicate information, its already present in sample_id when PERF_SAMPLE_CPU, and without that we don't care. > + * nr: Times of overhead happens. > + * E.g. for NMI, nr == times of NMI handler are called. > + * time: Total overhead cost(ns) > + */ > +struct perf_overhead_entry { > + __u32 cpu; > + __u64 nr; > + __u64 time; > +};