From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935334AbaH0Q37 (ORCPT ); Wed, 27 Aug 2014 12:29:59 -0400 Received: from kanga.kvack.org ([205.233.56.17]:39475 "EHLO kanga.kvack.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933798AbaH0Q35 (ORCPT ); Wed, 27 Aug 2014 12:29:57 -0400 Date: Wed, 27 Aug 2014 12:29:55 -0400 From: Benjamin LaHaise To: Maxim Patlasov Cc: Ming Lei , Jens Axboe , Christoph Hellwig , Linux Kernel Mailing List , Andrew Morton , Dave Kleikamp , Zach Brown , Kent Overstreet , open list: AIO , Linux FS Devel , Dave Chinner , ; Illegal-Object: Syntax error in Cc: address found on vger.kernel.org: Cc: ; ^-missing semicolon to end mail group, extraneous tokens in mailbox, missing end of mailbox Subject: Re: [PATCH v1 5/9] block: loop: convert to blk-mq Message-ID: <20140827162955.GF4827@kvack.org> References: <20140815163111.GA16652@infradead.org> <53EE370D.1060106@kernel.dk> <53EE3966.60609@kernel.dk> <53F0EAEC.9040505@kernel.dk> <53F3B89D.6070703@kernel.dk> <53FE029B.1030200@parallels.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53FE029B.1030200@parallels.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 27, 2014 at 08:08:59PM +0400, Maxim Patlasov wrote: ... > 1) /dev/loop0 of 3.17.0-rc1 with Ming's patches applied -- 11K iops > 2) the same as above, but call loop_queue_work() directly from > loop_queue_rq() -- 270K iops > 3) /dev/nullb0 of 3.17.0-rc1 -- 380K iops > > Taking into account so big difference (11K vs. 270K), would it be worthy > to implement pure non-blocking version of aio_kernel_submit() returning > error if blocking needed? Then loop driver (or any other in-kernel user) > might firstly try that non-blocking submit as fast-path, and, only if > it's failed, fall back to queueing. What filesystem is the backing file for loop0 on? O_DIRECT access as Ming's patches use should be non-blocking, and if not, that's something to fix. -ben -- "Thought is the essence of where you are now." From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin LaHaise Subject: Re: [PATCH v1 5/9] block: loop: convert to blk-mq Date: Wed, 27 Aug 2014 12:29:55 -0400 Message-ID: <20140827162955.GF4827@kvack.org> References: <20140815163111.GA16652@infradead.org> <53EE370D.1060106@kernel.dk> <53EE3966.60609@kernel.dk> <53F0EAEC.9040505@kernel.dk> <53F3B89D.6070703@kernel.dk> <53FE029B.1030200@parallels.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ming Lei , Jens Axboe , Christoph Hellwig , Linux Kernel Mailing List , Andrew Morton , Dave Kleikamp , Zach Brown , Kent Overstreet , open list: AIO , Linux FS Devel , Dave Chinner ; To: Maxim Patlasov Return-path: Content-Disposition: inline In-Reply-To: <53FE029B.1030200@parallels.com> Sender: owner-linux-aio@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Wed, Aug 27, 2014 at 08:08:59PM +0400, Maxim Patlasov wrote: ... > 1) /dev/loop0 of 3.17.0-rc1 with Ming's patches applied -- 11K iops > 2) the same as above, but call loop_queue_work() directly from > loop_queue_rq() -- 270K iops > 3) /dev/nullb0 of 3.17.0-rc1 -- 380K iops > > Taking into account so big difference (11K vs. 270K), would it be worthy > to implement pure non-blocking version of aio_kernel_submit() returning > error if blocking needed? Then loop driver (or any other in-kernel user) > might firstly try that non-blocking submit as fast-path, and, only if > it's failed, fall back to queueing. What filesystem is the backing file for loop0 on? O_DIRECT access as Ming's patches use should be non-blocking, and if not, that's something to fix. -ben -- "Thought is the essence of where you are now." -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: aart@kvack.org