From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shaohua Li Subject: Re: [PATCH v4 0/8] raid5-cache: enabling cache features Date: Wed, 12 Oct 2016 10:52:02 -0700 Message-ID: <20161012175202.GA58645@kernel.org> References: <20161011002446.2002428-1-songliubraving@fb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20161011002446.2002428-1-songliubraving@fb.com> Sender: linux-raid-owner@vger.kernel.org To: Song Liu Cc: linux-raid@vger.kernel.org, neilb@suse.com, shli@fb.com, kernel-team@fb.com, dan.j.williams@intel.com, hch@infradead.org, liuzhengyuang521@gmail.com, liuzhengyuan@kylinos.cn List-Id: linux-raid.ids On Mon, Oct 10, 2016 at 05:24:38PM -0700, Song Liu wrote: > These are the 4th version of patches to enable write cache part of > raid5-cache. The journal part was released with kernel 4.4. > > The caching part uses same disk format of raid456 journal, and provides > acceleration to writes. Write operations are committed (bio_endio) once > the data is secured in journal. Reconstruct and RMW are postponed to > reclaim path, which is (hopefully) not on the critical path. > > The changes are organized in 8 patches (details below). > > Patch for chunk_aligned_read in earlier RFC is not included yet > (http://marc.info/?l=linux-raid&m=146432700719277). But we may still need > some optimizations later, especially for SSD raid devices. > > Changes from PATCH v3 (http://marc.info/?l=linux-raid&m=147573807306070): > 1. Make reclaim robust > 2. Fix a bug in recovery > > Changes between v3 and v2 (http://marc.info/?l=linux-raid&m=147493266208102): > 1. Incorporate feedback from Shaohua > 2. Reorganize the patches, for hopefully easier review > 3. Make sure no change to write through mode (journal only) > 4. Change reclaim design to avoid deadlock due to log space Could you please add a test case for this in mdadm test suites? Thanks, Shaohua