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| author |   Tejun Heo <tj@kernel.org> | 2010-05-08 16:20:53 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2010-05-08 17:12:33 +0200 |
| commit | bbf1bb3eee86f2eef2baa14e600be454d09109ee (patch) | |
| tree | f7c200742a2d6ce20e72ad976b66d30d1aa6a04d /kernel | |
| parent | rcu: need barrier() in UP synchronize_sched_expedited() (diff) | |
| download | linux-dev-bbf1bb3eee86f2eef2baa14e600be454d09109ee.tar.xz linux-dev-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')
| -rw-r--r-- | kernel/Makefile | 2 | ||||
| -rw-r--r-- | kernel/stop_machine.c | 4 |
2 files changed, 5 insertions, 1 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index a987aa1676b5..149e18ef1ab1 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -68,7 +68,7 @@ obj-$(CONFIG_USER_NS) += user_namespace.o obj-$(CONFIG_PID_NS) += pid_namespace.o obj-$(CONFIG_IKCONFIG) += configs.o obj-$(CONFIG_RESOURCE_COUNTERS) += res_counter.o -obj-$(CONFIG_STOP_MACHINE) += stop_machine.o +obj-$(CONFIG_SMP) += stop_machine.o obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o obj-$(CONFIG_AUDIT) += audit.o auditfilter.o audit_watch.o obj-$(CONFIG_AUDITSYSCALL) += auditsc.o 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 */ |