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authorHeiko Carstens <heiko.carstens@de.ibm.com>2011-01-05 12:48:09 +0100
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2011-01-05 12:47:30 +0100
commitda7f51c11d5fedca9ba779ee220063ccb4f0a27e (patch)
treea8cd6d843e72128ad6bfef0f19ef601f27f56ba9
parent[S390] smp: delay idle task creation (diff)
downloadlinux-da7f51c11d5fedca9ba779ee220063ccb4f0a27e.tar.xz
linux-da7f51c11d5fedca9ba779ee220063ccb4f0a27e.zip
[S390] smp/idle: call init_idle() before starting a new cpu
Call init_idle() which (re-)initializes the idle task structure before it gets used on a new cpu. That way we can also get rid of the odd preempt_enable_no_resched() call we have in the cpu offline path within cpu_idle(). That call prevented preempt count imbalances between cpu hotplug operations. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--arch/s390/include/asm/smp.h3
-rw-r--r--arch/s390/kernel/process.c8
-rw-r--r--arch/s390/kernel/smp.c1
3 files changed, 5 insertions, 7 deletions
diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
index edc03cb9cd79..045e009fc164 100644
--- a/arch/s390/include/asm/smp.h
+++ b/arch/s390/include/asm/smp.h
@@ -20,7 +20,6 @@ extern void machine_power_off_smp(void);
extern int __cpu_disable (void);
extern void __cpu_die (unsigned int cpu);
-extern void cpu_die (void) __attribute__ ((noreturn));
extern int __cpu_up (unsigned int cpu);
extern struct mutex smp_cpu_state_mutex;
@@ -71,8 +70,10 @@ static inline void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
#ifdef CONFIG_HOTPLUG_CPU
extern int smp_rescan_cpus(void);
+extern void __noreturn cpu_die(void);
#else
static inline int smp_rescan_cpus(void) { return 0; }
+static inline void cpu_die(void) { }
#endif
#endif /* __ASM_SMP_H */
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index b825b3e1cb17..c2fffb57d727 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -42,6 +42,7 @@
#include <asm/irq.h>
#include <asm/timer.h>
#include <asm/nmi.h>
+#include <asm/smp.h>
#include "entry.h"
asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
@@ -76,13 +77,8 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
*/
static void default_idle(void)
{
- /* CPU is going idle. */
-#ifdef CONFIG_HOTPLUG_CPU
- if (cpu_is_offline(smp_processor_id())) {
- preempt_enable_no_resched();
+ if (cpu_is_offline(smp_processor_id()))
cpu_die();
- }
-#endif
local_irq_disable();
if (need_resched()) {
local_irq_enable();
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 8e84b5af49ba..10766be524eb 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -575,6 +575,7 @@ int __cpuinit __cpu_up(unsigned int cpu)
idle = c_idle.idle;
current_set[cpu] = c_idle.idle;
}
+ init_idle(idle, cpu);
if (smp_alloc_lowcore(cpu))
return -ENOMEM;
do {