sched/debug: Remove mpol_get/put and task_lock/unlock from sched_show_numa

The older format of /proc/pid/sched printed home node info which
required the mempolicy and task lock around mpol_get(). However
the format has changed since then and there is no need for
sched_show_numa() any more to have mempolicy argument,
asssociated mpol_get/put and task_lock/unlock. Remove them.

Fixes: 397f2378f1 ("sched/numa: Fix numa balancing stats in /proc/pid/sched")
Signed-off-by: Bharata B Rao <bharata@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lore.kernel.org/r/20220118050515.2973-1-bharata@amd.com

kernel/sched/debug.c

@@ -931,25 +931,15 @@ void print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
 static void sched_show_numa(struct task_struct *p, struct seq_file *m)
 {
 #ifdef CONFIG_NUMA_BALANCING
-	struct mempolicy *pol;
-
 	if (p->mm)
 		P(mm->numa_scan_seq);
 
-	task_lock(p);
-	pol = p->mempolicy;
-	if (pol && !(pol->flags & MPOL_F_MORON))
-		pol = NULL;
-	mpol_get(pol);
-	task_unlock(p);
-
 	P(numa_pages_migrated);
 	P(numa_preferred_nid);
 	P(total_numa_faults);
 	SEQ_printf(m, "current_node=%d, numa_group_id=%d\n",
 			task_node(p), task_numa_group_id(p));
 	show_numa_stats(p, m);
-	mpol_put(pol);
 #endif
 }