From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:57154) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SwHFr-0005Mg-AY for qemu-devel@nongnu.org; Tue, 31 Jul 2012 14:33:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SwHFp-0008RR-Mm for qemu-devel@nongnu.org; Tue, 31 Jul 2012 14:33:15 -0400 Received: from mailout3.w1.samsung.com ([210.118.77.13]:31506) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SwHFp-0008R4-HF for qemu-devel@nongnu.org; Tue, 31 Jul 2012 14:33:13 -0400 Received: from eusync3.samsung.com (mailout3.w1.samsung.com [210.118.77.13]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0M8100MFZFK9RJB0@mailout3.w1.samsung.com> for qemu-devel@nongnu.org; Tue, 31 Jul 2012 19:33:45 +0100 (BST) Received: from [106.109.9.180] by eusync3.samsung.com (Oracle Communications Messaging Server 7u4-23.01(7.0.4.23.0) 64bit (built Aug 10 2011)) with ESMTPA id <0M81004WRFJAMJ50@eusync3.samsung.com> for qemu-devel@nongnu.org; Tue, 31 Jul 2012 19:33:11 +0100 (BST) Message-id: <501824E4.7070601@samsung.com> Date: Tue, 31 Jul 2012 22:33:08 +0400 From: Igor Mitsyanko MIME-version: 1.0 References: <1343417387-13953-1-git-send-email-i.mitsyanko@samsung.com> <1343417387-13953-11-git-send-email-i.mitsyanko@samsung.com> <501816D0.9040207@samsung.com> <87wr1jyez2.fsf@codemonkey.ws> In-reply-to: <87wr1jyez2.fsf@codemonkey.ws> Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit Subject: Re: [Qemu-devel] [PATCH V4 10/12] SD card users: optimize access to SDClass methods List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: kwolf@redhat.com, Peter Maydell , benoit.canet@gmail.com, wdongxu@linux.vnet.ibm.com, stefanha@linux.vnet.ibm.com, e.voevodin@samsung.com, qemu-devel@nongnu.org, armbru@redhat.com, andrew.zaborowski@intel.com, kyungmin.park@samsung.com, pbonzini@redhat.com On 07/31/2012 10:15 PM, Anthony Liguori wrote: > How many loop iterations that? 300us is a huge amount of time, unless > you were looping on every byte, I have a hard time understanding that > delta. I'm not sure I understand what you mean, I did loop on every byte, that's how our SD model works. So, for 4K bytes qemu have to call SD_GET_CLASS >4K times. Or you're asking about write sequence length? It was 10 writes of 4096 bytes (not statistically reliable, I have to agree).