Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935815Ab3DQREy (ORCPT ); Wed, 17 Apr 2013 13:04:54 -0400 Received: from smtp.eu.citrix.com ([46.33.159.39]:20094 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754726Ab3DQREx (ORCPT ); Wed, 17 Apr 2013 13:04:53 -0400 X-IronPort-AV: E=Sophos;i="4.87,494,1363132800"; d="scan'208";a="3659627" Message-ID: <516ED633.3040205@citrix.com> Date: Wed, 17 Apr 2013 19:04:51 +0200 From: =?ISO-8859-1?Q?Roger_Pau_Monn=E9?= User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/20130328 Thunderbird/17.0.5 MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: "linux-kernel@vger.kernel.org" , "xen-devel@lists.xen.org" Subject: Re: [PATCH v1 7/7] xen-block: implement indirect descriptors References: <1364382643-3711-1-git-send-email-roger.pau@citrix.com> <1364382643-3711-8-git-send-email-roger.pau@citrix.com> <20130409184923.GA4978@phenom.dumpdata.com> <516C3264.3050409@citrix.com> <20130417142554.GG21378@phenom.dumpdata.com> In-Reply-To: <20130417142554.GG21378@phenom.dumpdata.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1326 Lines: 29 On 17/04/13 16:25, Konrad Rzeszutek Wilk wrote: >>> Perhaps the xen-blkfront part of the patch should be just split out to make >>> this easier? >>> >>> Perhaps what we really should have is just the 'max' value of megabytes >>> we want to handle on the ring. >>> >>> As right now 32 ring requests * 32 segments = 4MB. But if the user wants >>> to se the max: 32 * 4096 = so 512MB (right? each request would handle now 16MB >>> and since we have 32 of them = 512MB). >> >> I've just set that to something that brings a performance benefit >> without having to map an insane number of persistent grants in blkback. >> >> Yes, the values are correct, but the device request queue (rq) is only >> able to provide read requests with 64 segments or write requests with >> 128 segments. I haven't been able to get larger requests, even when >> setting this to 512 or higer. > > What are you using to drive the requests? 'fio'? Yes, I've tried fio with several "bs=" values, but it doesn't seem to change the size of the underlying requests. Have you been able to get bigger requests? -- 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/