smpboot: allow passing the cpumask on per-cpu thread registration
It makes the registration cheaper and simpler for the smpboot per-cpu
kthread users that don't need to always update the cpumask after threads
creation.
[sfr@canb.auug.org.au: fix for allow passing the cpumask on per-cpu thread registration]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index 60aa858..a818cbc 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -273,19 +273,22 @@
}
/**
- * smpboot_register_percpu_thread - Register a per_cpu thread related to hotplug
+ * smpboot_register_percpu_thread_cpumask - Register a per_cpu thread related
+ * to hotplug
* @plug_thread: Hotplug thread descriptor
+ * @cpumask: The cpumask where threads run
*
* Creates and starts the threads on all online cpus.
*/
-int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread)
+int smpboot_register_percpu_thread_cpumask(struct smp_hotplug_thread *plug_thread,
+ const struct cpumask *cpumask)
{
unsigned int cpu;
int ret = 0;
if (!alloc_cpumask_var(&plug_thread->cpumask, GFP_KERNEL))
return -ENOMEM;
- cpumask_copy(plug_thread->cpumask, cpu_possible_mask);
+ cpumask_copy(plug_thread->cpumask, cpumask);
get_online_cpus();
mutex_lock(&smpboot_threads_lock);
@@ -296,7 +299,8 @@
free_cpumask_var(plug_thread->cpumask);
goto out;
}
- smpboot_unpark_thread(plug_thread, cpu);
+ if (cpumask_test_cpu(cpu, cpumask))
+ smpboot_unpark_thread(plug_thread, cpu);
}
list_add(&plug_thread->list, &hotplug_threads);
out:
@@ -304,7 +308,7 @@
put_online_cpus();
return ret;
}
-EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread);
+EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread_cpumask);
/**
* smpboot_unregister_percpu_thread - Unregister a per_cpu thread related to hotplug