Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754432AbcDJOhw (ORCPT ); Sun, 10 Apr 2016 10:37:52 -0400 Received: from casper.infradead.org ([85.118.1.10]:60642 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753572AbcDJOht (ORCPT ); Sun, 10 Apr 2016 10:37:49 -0400 Date: Sun, 10 Apr 2016 15:37:42 +0100 (BST) From: James Simmons To: Christoph Hellwig cc: Ming Lei , Jens Axboe , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Boaz Harrosh , Oleg Drokin , Andreas Dilger , Greg Kroah-Hartman , "John L. Hammond" , Frank Zago , Mike Rapoport , Kent Overstreet , Julia Lawall , Al Viro , "moderated list:STAGING - LUSTRE PARALLEL FILESYSTEM" , "open list:STAGING SUBSYSTEM" Subject: Re: [PATCH 08/27] staging: lustre: avoid to use bio->bi_vcnt directly In-Reply-To: <20160405130109.GB32576@infradead.org> Message-ID: References: <1459857443-20611-1-git-send-email-tom.leiming@gmail.com> <1459857443-20611-9-git-send-email-tom.leiming@gmail.com> <20160405130109.GB32576@infradead.org> User-Agent: Alpine 2.20 (LFD 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160410_153742_918477_BD2F14F5 X-CRM114-Status: GOOD ( 10.40 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.4.0 on casper.infradead.org summary: Content analysis details: (-1.9 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 NO_RELAYS Informational: message was not relayed via SMTP -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 605 Lines: 12 > The lloop driver should be removed entirely - use the loop driver > instead. I talked with Andreas last week at our annual Lustre users group meeting about this. The reason I was told for existance is that some users were using files on a Lustre file system with the loop back device. The performance was really bad at the time so a lloop was developed to overcome those limitations. Its been a long time so perhaps its time to look at the default loop driver again to see if can perform now. If it doesn't we will go the route of reworking the lloop driver in the spirit of the cryptoloop device.