From e46b1db249d83bb19b6bdbed2b2e2ff3858cd211 Mon Sep 17 00:00:00 2001 From: Anna-Maria Gleixner Date: Sun, 27 Nov 2016 00:13:42 +0100 Subject: [PATCH] mm/compaction: Convert to hotplug state machine Install the callbacks via the state machine. Should the hotplug init fail then no threads are spawned. Signed-off-by: Anna-Maria Gleixner Signed-off-by: Sebastian Andrzej Siewior Cc: Michal Hocko Cc: Mel Gorman Cc: linux-mm@kvack.org Cc: rt@linutronix.de Cc: Andrew Morton Cc: Vlastimil Babka Link: http://lkml.kernel.org/r/20161126231350.10321-15-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- mm/compaction.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index 0409a4ad6ea1..0d37192d9423 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -2043,33 +2043,38 @@ void kcompactd_stop(int nid) * 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 kcompactd_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->kcompactd, mask); - } + if (cpumask_any_and(cpu_online_mask, mask) < nr_cpu_ids) + /* One of our CPUs online: restore mask */ + set_cpus_allowed_ptr(pgdat->kcompactd, mask); } - return NOTIFY_OK; + return 0; } static int __init kcompactd_init(void) { int nid; + int ret; + + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, + "mm/compaction:online", + kcompactd_cpu_online, NULL); + if (ret < 0) { + pr_err("kcompactd: failed to register hotplug callbacks.\n"); + return ret; + } for_each_node_state(nid, N_MEMORY) kcompactd_run(nid); - hotcpu_notifier(cpu_callback, 0); return 0; } subsys_initcall(kcompactd_init) -- 2.39.5