Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752056AbbEYPIb (ORCPT ); Mon, 25 May 2015 11:08:31 -0400 Received: from verein.lst.de ([213.95.11.211]:43586 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751888AbbEYPI3 (ORCPT ); Mon, 25 May 2015 11:08:29 -0400 Date: Mon, 25 May 2015 17:08:27 +0200 From: Christoph Hellwig To: Ilya Dryomov Cc: Ming Lin , "linux-kernel@vger.kernel.org" , Kent Overstreet , Jens Axboe , Dongsu Park , Lars Ellenberg , drbd-user@lists.linbit.com, Jiri Kosina , Yehuda Sadeh , Sage Weil , Alex Elder , Ceph Development , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, Neil Brown , linux-raid@vger.kernel.org, "Martin K. Petersen" , Alex Elder Subject: Re: [PATCH v4 08/11] block: kill merge_bvec_fn() completely Message-ID: <20150525150827.GA27012@lst.de> References: <1432318723-18829-1-git-send-email-mlin@kernel.org> <1432318723-18829-9-git-send-email-mlin@kernel.org> <20150525140413.GA26065@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1448 Lines: 27 On Mon, May 25, 2015 at 06:02:30PM +0300, Ilya Dryomov wrote: > I'm not Alex, but yeah, we have all the clone/split machinery and so we > can handle a spanning case just fine. I think rbd_merge_bvec() exists > to make sure we don't have to do that unless it's really necessary - > like when a single page gets submitted at an inconvenient offset. > > I have a patch that adds a blk_queue_chunk_sectors(object_size) call to > rbd_init_disk() but I haven't had a chance to play with it yet. In any > case, we should be fine with getting rid of rbd_merge_bvec(). If this > ends up a per-driver patchset, I can make rbd_merge_bvec() -> > blk_queue_chunk_sectors() a single patch and push it through > ceph-client.git. Hmm, looks like the new blk_queue_split_bio ignore the chunk_sectors value, another thing that needs updating. I forgot how many weird merging hacks we had to add for nvme.. While I'd like to see per-driver patches we'd still need to merge them together through the block tree. Note that with this series there won't be any benefit of using blk_queue_chunk_sectors over just doing the split in rbd. Maybe we can even remove it again and do that work in the drivers in the future. -- 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/