From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2001:1868:205::9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 6741E1A02E8 for ; Tue, 17 Mar 2015 17:55:02 +1100 (AEDT) Date: Tue, 17 Mar 2015 07:54:53 +0100 From: Peter Zijlstra To: Sukadev Bhattiprolu Subject: Re: [PATCH 3/4] perf: Add 'update' parameter to perf_event_read_value() Message-ID: <20150317065453.GM2896@worktop.programming.kicks-ass.net> References: <1425458108-3341-1-git-send-email-sukadev@linux.vnet.ibm.com> <1425458108-3341-4-git-send-email-sukadev@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1425458108-3341-4-git-send-email-sukadev@linux.vnet.ibm.com> Cc: dev@codyps.com, Paul Mackerras , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Mar 04, 2015 at 12:35:07AM -0800, Sukadev Bhattiprolu wrote: > extern u64 perf_event_read_value(struct perf_event *event, > - u64 *enabled, u64 *running); > + u64 *enabled, u64 *running, int update); > I think someone recently showed that bool generates better code in some cases. The advantage of int is that you can stuff more bits in, but then you need to call it flags or so anyhow. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752325AbbCQGzG (ORCPT ); Tue, 17 Mar 2015 02:55:06 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:46332 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750958AbbCQGzB (ORCPT ); Tue, 17 Mar 2015 02:55:01 -0400 Date: Tue, 17 Mar 2015 07:54:53 +0100 From: Peter Zijlstra To: Sukadev Bhattiprolu Cc: Michael Ellerman , Paul Mackerras , dev@codyps.com, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 3/4] perf: Add 'update' parameter to perf_event_read_value() Message-ID: <20150317065453.GM2896@worktop.programming.kicks-ass.net> References: <1425458108-3341-1-git-send-email-sukadev@linux.vnet.ibm.com> <1425458108-3341-4-git-send-email-sukadev@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1425458108-3341-4-git-send-email-sukadev@linux.vnet.ibm.com> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 04, 2015 at 12:35:07AM -0800, Sukadev Bhattiprolu wrote: > extern u64 perf_event_read_value(struct perf_event *event, > - u64 *enabled, u64 *running); > + u64 *enabled, u64 *running, int update); > I think someone recently showed that bool generates better code in some cases. The advantage of int is that you can stuff more bits in, but then you need to call it flags or so anyhow.