Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759869AbZDBOPA (ORCPT ); Thu, 2 Apr 2009 10:15:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757961AbZDBOOt (ORCPT ); Thu, 2 Apr 2009 10:14:49 -0400 Received: from mailgw.nyc.medallion.com ([63.68.220.242]:1138 "EHLO mailgw.nyc.medallion.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756209AbZDBOOr convert rfc822-to-8bit (ORCPT ); Thu, 2 Apr 2009 10:14:47 -0400 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.4325 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Subject: RE: [Scst-devel] [Iscsitarget-devel] ISCSI-SCST performance (with also IET and STGT data) Date: Thu, 2 Apr 2009 10:14:45 -0400 Message-ID: In-Reply-To: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [Scst-devel] [Iscsitarget-devel] ISCSI-SCST performance (with also IET and STGT data) Thread-Index: AcmzccVXprZxray5RuGN9SHeXbCCpAAKSY+wAACEwzA= References: <49D10256.8030307@vlnb.net> <49D11096.3070804@vlnb.net> <49D254E4.8050806@vlnb.net> <1238617423.3318.82.camel@mulgrave.int.hansenpartnership.com> <49D46B8B.5000708@vlnb.net> <49D47F28.3060409@vlnb.net> From: "Ross S. W. Walker" Importance: normal To: "Vladislav Bolkhovitin" , "James Bottomley" Cc: , "iSCSI Enterprise Target Developer List" , , "Ross Walker" , "scst-devel" , X-OriginalArrivalTime: 02 Apr 2009 14:14:45.0370 (UTC) FILETIME=[5FB4EDA0:01C9B39D] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2151 Lines: 54 Ross S. W. Walker wrote: > Vladislav Bolkhovitin wrote: > > Vladislav Bolkhovitin, on 04/02/2009 11:38 AM wrote: > > > James Bottomley, on 04/02/2009 12:23 AM wrote: > > >> > > >> SCST explicitly fiddles with the io context to get this to happen. It > > >> has a hack to block to export alloc_io_context: > > >> > > >> http://marc.info/?t=122893564800003 > > > > > > Correct, although I wouldn't call it "fiddle", rather "grouping" ;) > > Call it what you like, > > Vladislav Bolkhovitin wrote: > > Ross S. W. Walker, on 03/30/2009 10:33 PM wrote: > > > > I would be interested in knowing how your code defeats CFQ's extremely > > high latency? Does your code reach into the io scheduler too? If not, > > some code hints would be great. > The above quoting was wrong, for accuracy, it should have read: Vladislav Bolkhovitin wrote: > Ross S. W. Walker, on 03/30/2009 10:33 PM wrote: > > > > I would be interested in knowing how your code defeats CFQ's extremely > > high latency? Does your code reach into the io scheduler too? If not, > > some code hints would be great. > > Hmm, CFQ doesn't have any extra processing latency, especially > "extremely", hence there is nothing to defeat. If it had, how could it > been chosen as the default? Just so there is no misunderstanding who said what here. -Ross ______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof. -- 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/