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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 <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Michael Holzheu 2014-04-15 11:25:28 +02:00 committed by Martin Schwidefsky
parent 0d234a2896
commit f4192bf2dc
2 changed files with 2 additions and 12 deletions
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5
arch/s390/include/asm/smp.h
View File

@ -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);

9
arch/s390/kernel/smp.c
View File

@ -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.