From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luis Chamberlain Subject: Re: [driver-core PATCH v8 0/9] Add NUMA aware async_schedule calls Date: Mon, 10 Dec 2018 15:35:07 -0800 Message-ID: <20181210233507.GK28501@garbanzo.do-not-panic.com> References: <154403054034.11544.3978949383914046587.stgit@ahduyck-desk1.jf.intel.com> <20181210192216.GJ28501@garbanzo.do-not-panic.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Alexander Duyck Cc: len.brown-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, bvanassche-HInyCGIudOg@public.gmane.org, linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, jiangshanlai-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, pavel-+ZI9xUNit7I@public.gmane.org, zwisler-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, rafael-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org List-Id: linux-pm@vger.kernel.org On Mon, Dec 10, 2018 at 03:25:04PM -0800, Alexander Duyck wrote: > On Mon, 2018-12-10 at 11:22 -0800, Luis Chamberlain wrote: > > On Wed, Dec 05, 2018 at 09:25:13AM -0800, Alexander Duyck wrote: > > > This patch set provides functionality that will help to improve the > > > locality of the async_schedule calls used to provide deferred > > > initialization. > > > > > > This patch set originally started out focused on just the one call to > > > async_schedule_domain in the nvdimm tree that was being used to defer the > > > device_add call however after doing some digging I realized the scope of > > > this was much broader than I had originally planned. As such I went > > > through and reworked the underlying infrastructure down to replacing the > > > queue_work call itself with a function of my own and opted to try and > > > provide a NUMA aware solution that would work for a broader audience. > > > > > > In addition I have added several tweaks and/or clean-ups to the front of the > > > patch set. Patches 1 through 4 address a number of issues that actually were > > > causing the existing async_schedule calls to not show the performance that > > > they could due to either not scaling on a per device basis, or due to issues > > > that could result in a potential deadlock. For example, patch 4 addresses the > > > fact that we were calling async_schedule once per driver instead of once > > > per device, and as a result we would have still ended up with devices > > > being probed on a non-local node without addressing this first. > > > > No tests were added. Again, I think it would be good to add test > > cases to showcase the old mechanisms, illustrate the new, and ensure > > we don't regress both now and also help us ensure we don't regress > > moving forward. > > > > This is all too critical of a path for the kernel, and these changes > > are rather instrusive. I'd readlly like to see test code for it now > > rather than later. > > > > Luis > > Sorry about that. I was more focused on the rewrite of patch 2 and > overlooked the comment about lib/test_kmod.c. > > I'll look into it and see if I can squeeze it in for v9. Superb! Luis