Re: [PATCH resend 2/8] sched: core scheduling tagging infrastructure

From: Peter Zijlstra
Date: Fri Mar 26 2021 - 20:19:01 EST


On Wed, Mar 24, 2021 at 05:40:14PM -0400, Joel Fernandes (Google) wrote:
> From: Josh Don <joshdon@xxxxxxxxxx>
>
> A single unsigned long is insufficient as a cookie value for core
> scheduling. We will minimally have cookie values for a per-task and a
> per-group interface, which must be combined into an overall cookie.
>
> This patch adds the infrastructure necessary for setting task and group
> cookie. Namely, it reworks the core_cookie into a struct, and provides
> interfaces for setting task and group cookie, as well as other
> operations (i.e. compare()). Subsequent patches will use these hooks to
> provide an API for setting these cookies.
>

*urgh*... so I specifically wanted the task interface first to avoid /
get-rid of all this madness. And then you keep it :-(

I've spend the past few hours rewriting patches #2 and #3, and adapting
#4. The thing was working before I added SHARE_FROM back and introduced
GET, but now I'm seeing a few FAILs from the selftest.

I'm too tired to make sense of anything much, or even focus my eyes
consistently, so I'll have to prod at it some more next week, but I've
pushed out the lot to my queue.git:

https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/log/?h=sched/core-sched

Also, we really need a better name than coretag.c.