From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Roper Subject: Re: [PATCH 1/2] Documentation/cgroup-v1: fix outdated programming details Date: Fri, 29 Dec 2017 12:34:49 -0800 Message-ID: <20171229203449.GS5820@mdroper-desk.amr.corp.intel.com> References: <20171229200200.18873-1-matthew.d.roper@intel.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20171229200200.18873-1-matthew.d.roper-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Tejun Heo On Fri, Dec 29, 2017 at 12:01:59PM -0800, Matt Roper wrote: > The cgroup-v1 documentation is out of date in a few places: > > * cgroup controllers can no longer be compiled as modules since commit > 3ed80a6 ("cgroup: drop module support"); the functions and fields > referenced here no longer exist. ... This is actually exactly what I was digging into the cgroups documentation to figure out how to do. I was hoping to be able to create a controller inside an existing device driver that could manage driver-specific policy and resources. However based on the explanation given in https://www.spinics.net/lists/cgroups/msg10077.html , it sounds like this isn't really a direction that the cgroups framework wants to go. My specific goal was to use the cgroups-v2 hierarchy to assign i915 (GPU) workloads with an initial priority according to the cgroup classification of the submitting process. In the future I could also see driver-specific cgroup controllers potentially being useful for managing specialized resources like graphics-specific stolen memory or video RAM on discrete gpu's. If a system is already using a cgroups-v2 hierarchy to manage other system resources via the standard controllers, I think it would be ideal if we could leverage that existing process organization to supply i915 with desired driver-specific policy and resource assignments. Since cgroup controllers don't seem to support this at the moment, is there an alternate mechanism I should be looking at instead? Or is this a type of use case that we may want to evolve cgroups to support in a different manner? Thanks! Matt -- Matt Roper Graphics Software Engineer IoTG Platform Enabling & Development Intel Corporation (916) 356-2795