Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932850Ab1C3Qxu (ORCPT ); Wed, 30 Mar 2011 12:53:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56939 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932707Ab1C3Qxs (ORCPT ); Wed, 30 Mar 2011 12:53:48 -0400 Date: Wed, 30 Mar 2011 12:53:42 -0400 From: Vivek Goyal To: Andreas Schwab Cc: linux-kernel@vger.kernel.org, jaxboe@fusionio.com, paulmck@linux.vnet.ibm.com, oleg@redhat.com Subject: Re: [PATCH] blk-throttle: don't call xchg on bool Message-ID: <20110330165342.GF1291@redhat.com> References: <1292447255-10698-1-git-send-email-vgoyal@redhat.com> <1292447255-10698-3-git-send-email-vgoyal@redhat.com> <20110330131936.GA1291@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 972 Lines: 30 On Wed, Mar 30, 2011 at 03:51:34PM +0200, Andreas Schwab wrote: > Vivek Goyal writes: > > > Which arch creates the problem and what's the issue here if data type > > is smaller than 32bit? > > Just look at the various implementations in arch/*/include/asm/system.h: > > - arm: supports only one and 4 byte xchg > - avr32: supports only 4 byte xchg > - frv: supports only 4 byte xchg > - m32r: SMP supports only 4 byte xchg > - microblaze: supports only one and 4 byte xchg > > etc. > > > Is it a compile time warning? > > Most implementations turn the use of xchg with a bad pointer into a link > error. Thanks Andreas. I get it. I did check arm and it is supporting only one and 4 byte xchg. Vivek -- 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/