From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [PATCH 1/3] perf events: fix WARN_ON_ONCE for 64-bit raw data, SW events Date: Fri, 18 Feb 2011 10:15:14 -0700 Message-ID: <4D5EA922.1090709@cisco.com> References: <1298008433-22911-1-git-send-email-daahern@cisco.com> <1298008433-22911-2-git-send-email-daahern@cisco.com> <1298026821.5226.642.camel@laptop> <4D5E8338.8010602@cisco.com> <20110218145348.GA302@ghostprotocols.net> <1298041291.5226.776.camel@laptop> <20110218170450.GB302@ghostprotocols.net> <1298049189.2887.1.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from sj-iport-5.cisco.com ([171.68.10.87]:48173 "EHLO sj-iport-5.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751599Ab1BRRPQ (ORCPT ); Fri, 18 Feb 2011 12:15:16 -0500 In-Reply-To: <1298049189.2887.1.camel@twins> Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: Peter Zijlstra Cc: Arnaldo Carvalho de Melo , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@elte.hu, paulus@samba.org On 02/18/11 10:13, Peter Zijlstra wrote: > On Fri, 2011-02-18 at 15:04 -0200, Arnaldo Carvalho de Melo wrote: >> Em Fri, Feb 18, 2011 at 04:01:31PM +0100, Peter Zijlstra escreveu: >>> On Fri, 2011-02-18 at 12:53 -0200, Arnaldo Carvalho de Melo wrote: >>>>> So size should be changed to u64 rather than modifying the >>>> WARN_ON_ONCE? >>>> >>>> Yeah, I guess so, 32-bit has to die it seems, gets in the way of >>>> testing >>>> :-) >>> >>> No! >>> >>> 1) don't use RAW unless you have to >>> 2) you don't have to, goto 1 >>> 3) if you do anyway, ensure its properly padded >> >> Ok, but using that struct definition on 32-bit land, will lead to non 8 byte >> alignment, right? > > Nope, its just fine.. it defaults to an empty 4byte payload ;-) > > Its just that any custom payload must be of size 4+8*n bytes. 4 + 8*n != 8-byte aligned for any whole number n. David