Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761311Ab2EJSeh (ORCPT ); Thu, 10 May 2012 14:34:37 -0400 Received: from mail-yx0-f174.google.com ([209.85.213.174]:41901 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760618Ab2EJSef (ORCPT ); Thu, 10 May 2012 14:34:35 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Thu, 10 May 2012 11:34:34 -0700 X-Google-Sender-Auth: 7XFtZOupMsigAK4-hwryhkj0G-Y Message-ID: Subject: Re: [Bcache v13 00/16] From: Dan Williams To: Kent Overstreet Cc: linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, tejun@google.com, Alasdair G Kergon , linux-raid Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2213 Lines: 48 On Wed, May 9, 2012 at 8:07 PM, Kent Overstreet wrote: > bcache: a cache for arbitrary block devices using an SSD. > > Short overview: > Bcache does both writethrough and writeback caching. It presents itself as a > new block device, a bit like say md. You can cache an arbitrary number of > block devices with a single cache device, and attach and detach things at > runtime - it's quite flexible. > > It's very fast. It uses a b+ tree for the index, along with a journal to > coalesce index updates, and a bunch of other cool tricks like auxiliary binary > search trees with software floating point keys for searching within btree > nodes. > > Bcache is solid, production ready code. There are still bugs being found that > affect specific configurations, but there haven't been any major issues found > in awhile - it's well past time I started working on getting it into mainline. > > It's a lot of code - I tried to split it out so that it'd make some sort of > sense for reviewing. Let me know if there's anything else I can do to make > review easier. > > TODO/known issues: > > __up_write() needs to be exported for bcache to compile as a module - it's > used for bypassing lockdep when traversing the btree during garbage > collection. If someone else knows a better solution, please let me know. > > The userspace interface is going to change before it goes in. The general > consensus at LSF was that we don't want yet another interface for > probing/managing block devices, and dm exists so we may as well use that. I > don't think anyone's started on that yet, though. Might as well mention I've started work on a md conversion. Nearing the point of having RFC patches ready to post. I'm doing it in such a way that it does not preclude a dm target from coming along as well. Like I mentioned to Alasdair at LSF, there's no reason this could not be treated the same as the shared raid personalities between dm and md. -- Dan -- 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/