mm/writeback: Convert to hotplug state machine
Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: linux-mm@kvack.org
Cc: rt@linutronix.de
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20160818125731.27256-6-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 82ee321..854e59a 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -16,6 +16,7 @@
CPUHP_X86_APB_DEAD,
CPUHP_VIRT_NET_DEAD,
CPUHP_SLUB_DEAD,
+ CPUHP_MM_WRITEBACK_DEAD,
CPUHP_WORKQUEUE_PREP,
CPUHP_POWER_NUMA_PREPARE,
CPUHP_HRTIMERS_PREPARE,
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index f4cd7d8..28d6f36 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2080,26 +2080,12 @@
ratelimit_pages = 16;
}
-static int
-ratelimit_handler(struct notifier_block *self, unsigned long action,
- void *hcpu)
+static int page_writeback_cpu_online(unsigned int cpu)
{
-
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_ONLINE:
- case CPU_DEAD:
- writeback_set_ratelimit();
- return NOTIFY_OK;
- default:
- return NOTIFY_DONE;
- }
+ writeback_set_ratelimit();
+ return 0;
}
-static struct notifier_block ratelimit_nb = {
- .notifier_call = ratelimit_handler,
- .next = NULL,
-};
-
/*
* Called early on to tune the page writeback dirty limits.
*
@@ -2122,8 +2108,10 @@
{
BUG_ON(wb_domain_init(&global_wb_domain, GFP_KERNEL));
- writeback_set_ratelimit();
- register_cpu_notifier(&ratelimit_nb);
+ cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mm/writeback:online",
+ page_writeback_cpu_online, NULL);
+ cpuhp_setup_state(CPUHP_MM_WRITEBACK_DEAD, "mm/writeback:dead", NULL,
+ page_writeback_cpu_online);
}
/**