Commit c6a566f6 authored by Frederic Weisbecker's avatar Frederic Weisbecker
Browse files

mm: Create/affine kswapd to its preferred node 



kswapd is dedicated to a specific node. As such it wants to be
preferrably affine to it, memory and CPUs-wise.

Use the proper kthread API to achieve that. As a bonus it takes care of
CPU-hotplug events and CPU-isolation on its behalf.

Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
parent 54880b5a

mm/vmscan.c

+3 −5
Original line number Diff line number Diff line
@@ -7182,10 +7182,6 @@ static int kswapd(void *p) 
	unsigned int highest_zoneidx = MAX_NR_ZONES - 1;

	pg_data_t *pgdat = (pg_data_t *)p;

	struct task_struct *tsk = current;

	const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);



	if (!cpumask_empty(cpumask))

		set_cpus_allowed_ptr(tsk, cpumask);



	/*

	 * Tell the memory management that we're a "memory allocator",
@@ -7354,13 +7350,15 @@ void __meminit kswapd_run(int nid) 


	pgdat_kswapd_lock(pgdat);

	if (!pgdat->kswapd) {

		pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);

		pgdat->kswapd = kthread_create_on_node(kswapd, pgdat, nid, "kswapd%d", nid);

		if (IS_ERR(pgdat->kswapd)) {

			/* failure at boot is fatal */

			pr_err("Failed to start kswapd on node %d，ret=%ld\n",

				   nid, PTR_ERR(pgdat->kswapd));

			BUG_ON(system_state < SYSTEM_RUNNING);

			pgdat->kswapd = NULL;

		} else {

			wake_up_process(pgdat->kswapd);

		}

	}

	pgdat_kswapd_unlock(pgdat);