hotplug: Fix UP bug in smpboot hotplug code

Because kernel subsystems need their per-CPU kthreads on UP systems as
well as on SMP systems, the smpboot hotplug kthread functions must be
provided in UP builds as well as in SMP builds.  This commit therefore
adds smpboot.c to UP builds and excludes irrelevant code via #ifdef.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/Makefile b/kernel/Makefile
index c0cc67ad764ceddbe9f226ee1bfb90c4055f19ff..e5602d32acb33f1af7200eb8754e367c16339cbd 100644 (file)
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -10,7 +10,7 @@ obj-y     = fork.o exec_domain.o panic.o printk.o \
            kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
            hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
            notifier.o ksysfs.o cred.o \
-           async.o range.o groups.o lglock.o
+           async.o range.o groups.o lglock.o smpboot.o
 
 ifdef CONFIG_FUNCTION_TRACER
 # Do not trace debug files and internal ftrace files
@@ -46,7 +46,6 @@ obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
 obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
 obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
 obj-$(CONFIG_SMP) += smp.o
-obj-$(CONFIG_SMP) += smpboot.o
 ifneq ($(CONFIG_SMP),y)
 obj-y += up.o
 endif

diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index 9d5f7b04025d858327b5c4cc018d312783134028..d6c5fc0542428dae4fffc7546e06b0f6dd4ac4f5 100644 (file)
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -15,6 +15,8 @@
 
 #include "smpboot.h"
 
+#ifdef CONFIG_SMP
+
 #ifdef CONFIG_GENERIC_SMP_IDLE_THREAD
 /*
  * For the hotplug case we keep the task structs around and reuse
@@ -72,6 +74,8 @@ void __init idle_threads_init(void)
 }
 #endif
 
+#endif /* #ifdef CONFIG_SMP */
+
 static LIST_HEAD(hotplug_threads);
 static DEFINE_MUTEX(smpboot_threads_lock);