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authorTejun Heo <tj@kernel.org>2010-05-08 16:20:53 +0200
committerTejun Heo <tj@kernel.org>2010-05-08 17:12:33 +0200
commitbbf1bb3eee86f2eef2baa14e600be454d09109ee (patch)
treef7c200742a2d6ce20e72ad976b66d30d1aa6a04d /kernel/stop_machine.c
parentrcu: need barrier() in UP synchronize_sched_expedited() (diff)
downloadlinux-bbf1bb3eee86f2eef2baa14e600be454d09109ee.tar.xz
linux-bbf1bb3eee86f2eef2baa14e600be454d09109ee.zip
cpu_stop: add dummy implementation for UP
When !CONFIG_SMP, cpu_stop functions weren't defined at all which could lead to build failures if UP code uses cpu_stop facility. Add dummy cpu_stop implementation for UP. The waiting variants execute the work function directly with preempt disabled and stop_one_cpu_nowait() schedules a workqueue work. Makefile and ifdefs around stop_machine implementation are updated to accomodate CONFIG_SMP && !CONFIG_STOP_MACHINE case. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/stop_machine.c')
-rw-r--r--kernel/stop_machine.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 5b20141a5ec1..ef51d1fcf5e6 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -375,6 +375,8 @@ static int __init cpu_stop_init(void)
}
early_initcall(cpu_stop_init);
+#ifdef CONFIG_STOP_MACHINE
+
/* This controls the threads on each CPU. */
enum stopmachine_state {
/* Dummy starting state for thread. */
@@ -477,3 +479,5 @@ int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
return ret;
}
EXPORT_SYMBOL_GPL(stop_machine);
+
+#endif /* CONFIG_STOP_MACHINE */