On 11/11/22 10:34, Sebastian Andrzej Siewior wrote:
On 2022-11-02 09:20:48 [-0400], Waiman Long wrote:
Hi,
Yes, that is a known issue which is especially problematic when cgroup v2 is
used. That is why I have recently posted a set of patches to enable
persistent user requested affinity and they have been merged into tip:
851a723e45d1 sched: Always clear user_cpus_ptr in do_set_cpus_allowed()
da019032819a sched: Enforce user requested affinity
8f9ea86fdf99 sched: Always preserve the user requested cpumask
713a2e21a513 sched: Introduce affinity_context
5584e8ac2c68 sched: Add __releases annotations to affine_move_task()
They should be able to address the problem that you list here. Please let me
know if there are still problem remaining.
Thank you. This solves the most pressing issue. The CPU-mask is still
reset upon activation of the cpuset controller.
This is due to the set_cpus_allowed_ptr() in cpuset_attach().
Is is possible to push these patches stable?
Actually, I prefer to not call set_cpus_allowed_ptr() if the cpumask of
the old and new cpusets are the same. That will save some cpu cycles.
Similarly for node_mask. If there is any changes in the cpumask, we have
to call set_cpus_allowed_ptr(). I will work out a patch to that effect
when I have spare cycle.
Thanks,
Longman
