From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: Re: [RFC workqueue/driver-core PATCH 1/5] workqueue: Provide queue_work_near to queue work near a given NUMA node Date: Wed, 26 Sep 2018 15:05:17 -0700 Message-ID: <9b002bbb-3e6d-9e99-d8f9-36df4306093e@linux.intel.com> References: <20180926214433.13512.30289.stgit@localhost.localdomain> <20180926215138.13512.33146.stgit@localhost.localdomain> <20180926215307.GA270328@devbig004.ftw2.facebook.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180926215307.GA270328@devbig004.ftw2.facebook.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Tejun Heo Cc: linux-nvdimm@lists.01.org, gregkh@linuxfoundation.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, len.brown@intel.com, dave.jiang@intel.com, rafael@kernel.org, vishal.l.verma@intel.com, jiangshanlai@gmail.com, pavel@ucw.cz, zwisler@kernel.org, dan.j.williams@intel.com List-Id: linux-pm@vger.kernel.org On 9/26/2018 2:53 PM, Tejun Heo wrote: > Hello, > > On Wed, Sep 26, 2018 at 02:51:38PM -0700, Alexander Duyck wrote: >> This patch provides a new function queue_work_near which is meant to >> schedule work on the nearest unbound CPU to the requested NUMA node. The >> main motivation for this is to help assist asynchronous init to better >> improve boot times for devices that are local to a specific node. >> >> Signed-off-by: Alexander Duyck > > Why not just use unbound workqueues, which are NUMA-affine by default? > Are there big enough advantages? > > Thanks. I am using unbound workqueues. However there isn't an interface that exposes the NUMA bits of them directly. All I am doing with this patch is adding "queue_work_near" which takes a NUMA node as an argument and then copies the logic of "queue_work_on" with the exception that I am doing a check to verify that there is an intersection between wq_unbound_cpumask and the cpumask of the node, and then passing a CPU from that intersection into "__queue_work". Thanks. - Alex