From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH] bitops: add _local bitops Date: Wed, 09 May 2012 12:23:30 -0700 Message-ID: <4FAAC432.5080503@zytor.com> References: <20120509134528.GA18044@redhat.com> <20120509121940.459e93ba.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120509121940.459e93ba.akpm@linux-foundation.org> Sender: linux-doc-owner@vger.kernel.org To: Andrew Morton Cc: "Michael S. Tsirkin" , Rob Landley , Thomas Gleixner , Ingo Molnar , x86@kernel.org, Arnd Bergmann , David Howells , Akinobu Mita , Alexey Dobriyan , Herbert Xu , Stephen Rothwell , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Gleb Natapov , Paolo Bonzini , kvm@vger.kernel.org, Avi Kivity , Marcelo Tosatti , Linus Torvalds List-Id: linux-arch.vger.kernel.org On 05/09/2012 12:19 PM, Andrew Morton wrote: > > Secondly: can KVM just use __set_bit() and friends? I suspect those > interfaces happen to meet your requirements. At least on architectures > you care about. > __set_bit() and friends right now don't have optimization barriers, meaning the compiler is free to move them around. -hpa From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from terminus.zytor.com ([198.137.202.10]:43450 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756153Ab2EITX5 (ORCPT ); Wed, 9 May 2012 15:23:57 -0400 Message-ID: <4FAAC432.5080503@zytor.com> Date: Wed, 09 May 2012 12:23:30 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: [PATCH] bitops: add _local bitops References: <20120509134528.GA18044@redhat.com> <20120509121940.459e93ba.akpm@linux-foundation.org> In-Reply-To: <20120509121940.459e93ba.akpm@linux-foundation.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Andrew Morton Cc: "Michael S. Tsirkin" , Rob Landley , Thomas Gleixner , Ingo Molnar , x86@kernel.org, Arnd Bergmann , David Howells , Akinobu Mita , Alexey Dobriyan , Herbert Xu , Stephen Rothwell , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Gleb Natapov , Paolo Bonzini , kvm@vger.kernel.org, Avi Kivity , Marcelo Tosatti , Linus Torvalds Message-ID: <20120509192330.XmLDj9yhnvWs3_ifUi_07OLoyzJrUWB8nqebHDbLOZc@z> On 05/09/2012 12:19 PM, Andrew Morton wrote: > > Secondly: can KVM just use __set_bit() and friends? I suspect those > interfaces happen to meet your requirements. At least on architectures > you care about. > __set_bit() and friends right now don't have optimization barriers, meaning the compiler is free to move them around. -hpa