Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754797AbbG0WQY (ORCPT ); Mon, 27 Jul 2015 18:16:24 -0400 Received: from mail.kernel.org ([198.145.29.136]:48614 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754505AbbG0WQM (ORCPT ); Mon, 27 Jul 2015 18:16:12 -0400 MIME-Version: 1.0 In-Reply-To: <1438035090.28978.19.camel@ssi> References: <1436166674-31362-1-git-send-email-mlin@kernel.org> <1436764355.30675.10.camel@hasee> <20150713153537.GA30898@redhat.com> <1437675702.11359.25.camel@ssi> <20150727175048.GA18183@redhat.com> <1438035090.28978.19.camel@ssi> Date: Mon, 27 Jul 2015 15:16:08 -0700 Message-ID: Subject: Re: [PATCH v5 00/11] simplify block layer based on immutable biovecs From: Ming Lin To: Ming Lin Cc: Mike Snitzer , Jens Axboe , dm-devel@redhat.com, lkml , Christoph Hellwig , Jeff Moyer , Dongsu Park , Kent Overstreet , "Alasdair G. Kergon" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 728 Lines: 22 On Mon, Jul 27, 2015 at 3:11 PM, Ming Lin wrote: > It's more interesting if we look at how many bios are allocated for each > application IO request. > > e.g. 10+2 RAID6 with 128K chunk. > > Assume we only consider device max_segments limitation. > > # cat /sys/block/md0/queue/max_segments > 126 > > So blk_queue_split() will split the bio if its size > 126 pages(504K > bytes). Fix myself. I mean, blk_queue_split() will split the bio if bi_phys_segments > 126 -- 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/