From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:43124) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QKlw7-0006xQ-JW for qemu-devel@nongnu.org; Fri, 13 May 2011 02:33:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QKlw6-0007ZO-Pv for qemu-devel@nongnu.org; Fri, 13 May 2011 02:33:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60839) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QKlw6-0007ZI-J8 for qemu-devel@nongnu.org; Fri, 13 May 2011 02:33:18 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p4D6XGp9020991 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 13 May 2011 02:33:16 -0400 Message-ID: <4DCCD0A9.9050706@redhat.com> Date: Fri, 13 May 2011 08:33:13 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1304441374-27314-1-git-send-email-pbonzini@redhat.com> <4DCBFD84.9040702@redhat.com> In-Reply-To: <4DCBFD84.9040702@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/4] introduce cpu_physical_memory_map_fast List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: qemu-devel@nongnu.org On 05/12/2011 05:32 PM, Avi Kivity wrote: > Out of curiosity, what performance benefit do you see? Zero. :) Also because the only real change is in patch 4/4 (milkymist) which I only compile-tested. In all other instances, using cpu_physical_memory_map_fast is just to make it clear that we don't want bounce buffers. However, this is just preparatory work for vmw_pvscsi, which will use the functions to build its iovecs. qemu_get_ram_ptr would not really be a satisfactory API for that. Paolo