On Fri, Mar 19, 2021 at 04:32:48PM -0400, Joel Fernandes (Google) wrote: > @@ -7530,8 +7543,9 @@ int can_migrate_task(struct task_struct *p, struct > lb_env *env) > * We do not migrate tasks that are: > * 1) throttled_lb_pair, or > * 2) cannot be migrated to this CPU due to cpus_ptr, or > - * 3) running (obviously), or > - * 4) are cache-hot on their current CPU. > + * 3) task's cookie does not match with this CPU's core cookie > + * 4) running (obviously), or > + * 5) are cache-hot on their current CPU. > */ > if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu)) > return 0; > @@ -7566,6 +7580,13 @@ int can_migrate_task(struct task_struct *p, struct > lb_env *env) > return 0; > } > > + /* > + * Don't migrate task if the task's cookie does not match > + * with the destination CPU's core cookie. > + */ > + if (!sched_core_cookie_match(cpu_rq(env->dst_cpu), p)) > + return 0; > + > /* Record that we found atleast one task that could run on dst_cpu */ > env->flags &= ~LBF_ALL_PINNED; >
This one is too strong.. persistent imbalance should be able to override it.
