From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42246) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bcZeI-0003oD-Ew for qemu-devel@nongnu.org; Wed, 24 Aug 2016 10:59:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bcZeD-00066j-Ut for qemu-devel@nongnu.org; Wed, 24 Aug 2016 10:59:25 -0400 Date: Wed, 24 Aug 2016 10:59:11 -0400 (EDT) From: Paolo Bonzini Message-ID: <1271571364.5255352.1472050751092.JavaMail.zimbra@redhat.com> In-Reply-To: <566a869d-1042-0bb7-7a4b-928efa5ea676@twiddle.net> References: <1472012279-20581-1-git-send-email-rth@twiddle.net> <20160824043048.109542.39014@ex-std-node742.prod.rhcloud.com> <535318f1-8178-714d-7487-5aeb0661280b@redhat.com> <566a869d-1042-0bb7-7a4b-928efa5ea676@twiddle.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/7] Improve buffer_is_zero List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson Cc: qemu-devel@nongnu.org, peter maydell , qemu-arm@nongnu.org, famz@redhat.com, vijay kilari ----- Original Message ----- > From: "Richard Henderson" > To: "Paolo Bonzini" , qemu-devel@nongnu.org > Cc: "peter maydell" , qemu-arm@nongnu.org, famz@redhat.com, "vijay kilari" > > Sent: Wednesday, August 24, 2016 4:53:37 PM > Subject: Re: [Qemu-devel] [PATCH 0/7] Improve buffer_is_zero > > On 08/23/2016 09:38 PM, Paolo Bonzini wrote: > > > > > > On 24/08/2016 06:30, no-reply@patchew.org wrote: > >> ERROR: Use of volatile is usually wrong: see > >> Documentation/volatile-considered-harmful.txt > >> #44: FILE: util/cutils.c:289: > >> + __asm volatile("vmovdqu -0x80(%1),%0\n\t" > > > > Other errors can be ignored, but please use __asm__ __volatile__ here or > > just __asm__ (I don't think volatile is useful). > > I had to add volatile to keep the prefetch in advance of the loop. > I suppose I could just add the prefetch to the asm block... Probably easiest, or maybe add barrier() too. Paolo