Re: [PATCH v5 01/18] cgroup/misc: Add per resource callbacks for CSS events

[Haitao Huang]

On Wed, 27 Sep 2023 04:20:55 -0500, Huang, Kai <kai.huang@xxxxxxxxx> wrote:

> On Fri, 2023-09-22 at 20:06 -0700, Haitao Huang wrote:
> > From: Kristen Carlson Accardi <kristen@xxxxxxxxxxxxxxx>
> >
> > The misc cgroup controller (subsystem) currently does not perform
> > resource type specific action for Cgroups Subsystem State (CSS) events:
> > the 'css_alloc' event when a cgroup is created and the 'css_free' event
> > when a cgroup is destroyed, or in event of user writing the max value to
> > the misc.max file to set the usage limit of a specific resource
> > [admin-guide/cgroup-v2.rst, 5-9. Misc].
> >
> > Define callbacks for those events and allow resource providers to
> > register the callbacks per resource type as needed. This will be
> > utilized later by the EPC misc cgroup support implemented in the SGX
> > driver:
> > - On css_alloc, allocate and initialize necessary structures for EPC
> > reclaiming, e.g., LRU list, work queue, etc.
> > - On css_free, cleanup and free those structures created in alloc.
> > - On max_write, trigger EPC reclaiming if the new limit is at or below
> > current usage.
>
> Nit:
>
> Wondering why we should trigger EPC reclaiming if the new limit is *at*  
> current
> usage?
>
> I actually don't quite care about why here, but writing these details in  
> the
> changelog may bring unnecessary confusion.  I guess you can just remove  
> all the
> details about what SGX driver needs to do on these callbacks.
Okay, I'll remove the three bullets on the SGX drive implementation  
details.

Thanks
Haitao