Hi Waiman,
On Mon, Mar 06, 2023 at 03:08:44PM -0500, Waiman Long wrote:
This patch series includes miscellaneous update to the cpuset and its testing code.
Patch 2 is actually a follow-up of commit 3fb906e7fabb ("cgroup/cpuset: Don't filter offline CPUs in cpuset_cpus_allowed() for top cpuset tasks").
Patches 3-4 are for handling corner cases when dealing with task_cpu_possible_mask().
Thanks for cc'ing me on these. I ran my arm64 asymmetric tests and, fwiw, I get the same results as vanilla -rc2, so that's good.
One behaviour that persists (and which I thought might be addressed by this series) is the following. Imagine a 4-CPU system with CPUs 0-1 being 64-bit only. If I configure a parent cpuset with 'cpuset.cpus' of "0-2" and a child cpuset with 'cpuset.cpus' of "0-1", then attaching a 32-bit task to the child cpuset will result in an affinity mask of 4. If I then change 'cpuset.cpus' of the parent cpuset to "0-1,3", the affinity mask of the task remains at '4' whereas it might be nice to update it to '8', in-line with the new affinity mask of the parent cpuset.
Anyway, I'm not complaining (this is certainly _not_ a regression), but I thought I'd highlight it in case you were aiming to address this with your changes.
Cheers,
Will