On 5/7/24 02:57, Xuewen Yan wrote:
These changes essentially reverts commit 851a723e45d1c("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()") except the additional caller in the cpuset code. How about the following less invasive change? diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 7019a40457a6..646837eab70c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2796,21 +2796,24 @@ __do_set_cpus_allowed(struct task_struct *p, struct affinity_context *ctx) } /* - * Used for kthread_bind() and select_fallback_rq(), in both cases the user - * affinity (if any) should be destroyed too. + * Used for kthread_bind() and select_fallback_rq(). Destroy user affinity + * if no intersection with the new mask. */ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) { struct affinity_context ac = { .new_mask = new_mask, .user_mask = NULL, - .flags = SCA_USER, /* clear the user requested mask */ + .flags = 0, }; union cpumask_rcuhead { cpumask_t cpumask; struct rcu_head rcu; }; + if (current->user_cpus_ptr && !cpumask_intersects(current->user_cpus_ptr, new_mask))Thanks for your suggestion, and I try it and as for me, it works well, but I change the "current" to p. I think “current” is inappropriate because what is changed here is the mask of p. It is possible that “p” and “current” are not equal. I would send the next patch later and add your Suggested-by. Thanks again for your advice!
You are right. It should be "p" instead of "current". Thanks, Longman
