[PATCH 07/25] mm/vmscan: Convert to hotplug state machine

From: Sebastian Andrzej Siewior
Date: Thu Nov 03 2016 - 10:54:58 EST


Install the callbacks via the state machine.

Cc: linux-mm@xxxxxxxxx
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
mm/vmscan.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 76fda2268148..b8404d32caf0 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3556,24 +3556,21 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
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 cpu_callback(struct notifier_block *nfb, unsigned long action,
- void *hcpu)
+static int kswapd_cpu_online(unsigned int cpu)
{
int nid;

- if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) {
- for_each_node_state(nid, N_MEMORY) {
- pg_data_t *pgdat = NODE_DATA(nid);
- const struct cpumask *mask;
+ 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);
+ 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);
- }
+ 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 NOTIFY_OK;
+ return 0;
}

/*
@@ -3615,12 +3612,15 @@ void kswapd_stop(int nid)

static int __init kswapd_init(void)
{
- int nid;
+ int nid, ret;

swap_setup();
for_each_node_state(nid, N_MEMORY)
kswapd_run(nid);
- hotcpu_notifier(cpu_callback, 0);
+ ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+ "mm/vmscan:online", kswapd_cpu_online,
+ NULL);
+ WARN_ON(ret < 0);
return 0;
}

--
2.10.2