From f4192bf2dc5ae3b24ffb004e771397e737ef01e0 Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Tue, 15 Apr 2014 11:25:28 +0200 Subject: [PATCH] s390/smp: Avoid busy loop after halt and "begin" on z/VM Currently the smp_stop_cpu() function for SMP kernels enters a busy loop when "begin" is entered on the z/VM console after Linux is halted. To avoid this behavior, use the non-SMP variant of smp_stop_cpu() which stops the CPU again after "begin" is entered. As a side effect we now have consistent behavior for SMP and non-SMP Linux. Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/smp.h | 5 ++--- arch/s390/kernel/smp.c | 9 --------- 2 files changed, 2 insertions(+), 12 deletions(-) diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h index 21703f85b48d..4f1307962a95 100644 --- a/arch/s390/include/asm/smp.h +++ b/arch/s390/include/asm/smp.h @@ -30,7 +30,6 @@ extern int smp_store_status(int cpu); extern int smp_vcpu_scheduled(int cpu); extern void smp_yield_cpu(int cpu); extern void smp_yield(void); -extern void smp_stop_cpu(void); extern void smp_cpu_set_polarization(int cpu, int val); extern int smp_cpu_get_polarization(int cpu); extern void smp_fill_possible_mask(void); @@ -54,6 +53,8 @@ static inline void smp_yield_cpu(int cpu) { } static inline void smp_yield(void) { } static inline void smp_fill_possible_mask(void) { } +#endif /* CONFIG_SMP */ + static inline void smp_stop_cpu(void) { u16 pcpu = stap(); @@ -64,8 +65,6 @@ static inline void smp_stop_cpu(void) } } -#endif /* CONFIG_SMP */ - #ifdef CONFIG_HOTPLUG_CPU extern int smp_rescan_cpus(void); extern void __noreturn cpu_die(void); diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 4b8b7f6284d1..243c7e512600 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -404,15 +404,6 @@ void smp_send_stop(void) } } -/* - * Stop the current cpu. - */ -void smp_stop_cpu(void) -{ - pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); - for (;;) ; -} - /* * This is the main routine where commands issued by other * cpus are handled. -- 2.20.1