Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754634Ab3JCP1u (ORCPT ); Thu, 3 Oct 2013 11:27:50 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:45970 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754595Ab3JCP1t (ORCPT ); Thu, 3 Oct 2013 11:27:49 -0400 Date: Thu, 3 Oct 2013 08:27:25 -0700 From: Sukadev Bhattiprolu To: Michael Ellerman Cc: Arnaldo Carvalho de Melo , Michael Ellerman , linux-kernel@vger.kernel.org, Stephane Eranian , linuxppc-dev@ozlabs.org, Paul Mackerras , Anshuman Khandual Subject: Re: [PATCH 6/9][v5] powerpc/perf: Define big-endian version of perf_mem_data_src Message-ID: <20131003152725.GA1383@us.ibm.com> References: <1380672911-12812-1-git-send-email-sukadev@linux.vnet.ibm.com> <1380672911-12812-7-git-send-email-sukadev@linux.vnet.ibm.com> <20131003053944.GD17237@concordia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131003053944.GD17237@concordia> X-Operating-System: Linux 2.0.32 on an i486 User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13100315-0320-0000-0000-0000013A514D Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1286 Lines: 32 Michael Ellerman [michael@ellerman.id.au] wrote: | On Tue, Oct 01, 2013 at 05:15:07PM -0700, Sukadev Bhattiprolu wrote: | > perf_mem_data_src is an union that is initialized via the ->val field | > and accessed via the bitmap fields. For this to work on big endian | > platforms, we also need a big-endian represenation of perf_mem_data_src. | > | > diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h | > index ca1d90b..846f399 100644 | > --- a/include/uapi/linux/perf_event.h | > +++ b/include/uapi/linux/perf_event.h | > @@ -19,6 +19,50 @@ | > #include | > | > /* | > + * Kernel and userspace check for endianness in incompatible ways. | > + * In user space, defines both __BIG_ENDIAN and __LITTLE_ENDIAN | > + * but sets __BYTE_ORDER to one or the other. So user space uses checks are: | | | Why can't you use __BIG_ENDIAN_BITFIELD ? BTW, any clues on why there are so many different ways of checking endianness ? Any standards related stuff or just evolution ? Sukadev -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/