sched/cache: Respect LLC preference in task migration and detach

sched/cache: Respect LLC preference in task migration and detach

During load balancing, make can_migrate_task()
consider a task's LLC preference.
Prevent a task from being moved out of its preferred LLC.

During the regular load balancing, if
the task cannot be migrated due to LLC locality, the
nr_balance_failed also should not be increased.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Co-developed-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/53da65f3d59de31e1a1dc59a4093d8dd9d4dc206.1775065312.git.tim.c.chen@linux.intel.com