The cpu online notification is used to adjust kswapd cpu affinity when a
NUMA node gains a new CPU.
Since currently we don't see a real runtime configuration like this,
let's drop this online notification for now.
Suggested-by: Michal Hocko <mhocko@xxxxxxxxxx>
Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
---
v3:
* remove the cpu online notification suggested by Michal
v2:
* rephrase the changelog
---
mm/vmscan.c | 27 +--------------------------
1 file changed, 1 insertion(+), 26 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 665f33258cd7..a4fdf3dc8887 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -4023,27 +4023,6 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
}
#endif /* CONFIG_HIBERNATION */
-/* It's optimal to keep kswapds on the same CPUs as their memory, but
- not required for correctness. So if the last cpu in a node goes
- away, we get changed to run anywhere: as the first one comes back,
- restore their cpu bindings. */
-static int kswapd_cpu_online(unsigned int cpu)
-{
- int nid;
-
- for_each_node_state(nid, N_MEMORY) {
- pg_data_t *pgdat = NODE_DATA(nid);
- const struct cpumask *mask;
-
- mask = cpumask_of_node(pgdat->node_id);
-
- if (cpumask_any_and(cpu_online_mask, mask) < nr_cpu_ids)
- /* One of our CPUs online: restore mask */
- set_cpus_allowed_ptr(pgdat->kswapd, mask);
- }
- return 0;
-}
-
/*
* This kswapd start function will be called by init and node-hot-add.
* On node-hot-add, kswapd will moved to proper cpus if cpus are hot-added.
@@ -4083,15 +4062,11 @@ void kswapd_stop(int nid)
static int __init kswapd_init(void)
{
- int nid, ret;
+ int nid;
swap_setup();
for_each_node_state(nid, N_MEMORY)
kswapd_run(nid);
- ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
- "mm/vmscan:online", kswapd_cpu_online,
- NULL);
- WARN_ON(ret < 0);
return 0;
}
--
2.17.1
