From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: Re: [RFC workqueue/driver-core PATCH 2/5] async: Add support for queueing on specific NUMA node Date: Thu, 27 Sep 2018 08:16:33 -0700 Message-ID: References: <20180926214433.13512.30289.stgit@localhost.localdomain> <20180926215143.13512.56522.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Dan Williams Cc: "Brown, Len" , Linux-pm mailing list , Greg KH , linux-nvdimm , jiangshanlai-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Linux Kernel Mailing List , zwisler-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, Pavel Machek , Tejun Heo , Andrew Morton , "Rafael J. Wysocki" List-Id: linux-pm@vger.kernel.org On 9/26/2018 5:31 PM, Dan Williams wrote: > On Wed, Sep 26, 2018 at 2:51 PM Alexander Duyck > wrote: >> >> This patch introduces four new variants of the async_schedule_ functions >> that allow scheduling on a specific NUMA node. >> >> The first two functions are async_schedule_near and >> async_schedule_near_domain which end up mapping to async_schedule and >> async_schedule_domain but provide NUMA node specific functionality. They >> replace the original functions which were moved to inline function >> definitions that call the new functions while passing NUMA_NO_NODE. >> >> The second two functions are async_schedule_dev and >> async_schedule_dev_domain which provide NUMA specific functionality when >> passing a device as the data member and that device has a NUMA node other >> than NUMA_NO_NODE. >> >> The main motivation behind this is to address the need to be able to >> schedule device specific init work on specific NUMA nodes in order to >> improve performance of memory initialization. >> >> Signed-off-by: Alexander Duyck > [..] >> /** >> - * async_schedule - schedule a function for asynchronous execution >> + * async_schedule_near - schedule a function for asynchronous execution >> * @func: function to execute asynchronously >> * @data: data pointer to pass to the function >> + * @node: NUMA node that we want to schedule this on or close to >> * >> * Returns an async_cookie_t that may be used for checkpointing later. >> * Note: This function may be called from atomic or non-atomic contexts. >> */ >> -async_cookie_t async_schedule(async_func_t func, void *data) >> +async_cookie_t async_schedule_near(async_func_t func, void *data, int node) >> { >> - return __async_schedule(func, data, &async_dfl_domain); >> + return async_schedule_near_domain(func, data, node, &async_dfl_domain); >> } >> -EXPORT_SYMBOL_GPL(async_schedule); >> +EXPORT_SYMBOL_GPL(async_schedule_near); > > Looks good to me. The _near() suffix makes it clear that we're doing a > best effort hint to the work placement compared to the strict > expectations of _on routines. > >> >> /** >> - * async_schedule_domain - schedule a function for asynchronous execution within a certain domain >> + * async_schedule_dev_domain - schedule a function for asynchronous execution within a certain domain >> * @func: function to execute asynchronously >> - * @data: data pointer to pass to the function >> + * @dev: device that we are scheduling this work for >> * @domain: the domain >> * >> - * Returns an async_cookie_t that may be used for checkpointing later. >> - * @domain may be used in the async_synchronize_*_domain() functions to >> - * wait within a certain synchronization domain rather than globally. A >> - * synchronization domain is specified via @domain. Note: This function >> - * may be called from atomic or non-atomic contexts. >> + * Device specific version of async_schedule_near_domain that provides some >> + * NUMA awareness based on the device node. >> + */ >> +async_cookie_t async_schedule_dev_domain(async_func_t func, struct device *dev, >> + struct async_domain *domain) >> +{ >> + return async_schedule_near_domain(func, dev, dev_to_node(dev), domain); >> +} >> +EXPORT_SYMBOL_GPL(async_schedule_dev_domain); > > This seems unnecessary and restrictive. Callers may want to pass > something other than dev as the parameter to the async function, and > dev_to_node() is not on onerous burden to place on callers. That is what async_schedule_near_domain is for, they can call that. The "dev" versions of the calls as just supposed to be helpers since one of the most common parameters to the async_schedule calls is a device, so I thought I would just put together a function that takes care of all this for us so I could drop an argument and avoid having to use dev_to_node everywhere.