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https://github.com/torvalds/linux
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255acee706
Introduce additional_cpus command line option. By default no additional cpu can be attached to the system anymore. Only the cpus present at IPL time can be switched on/off. If it is desired that additional cpus can be attached to the system the maximum number of additional cpus needs to be specified with this option. This change is necessary in order to limit the waste of per_cpu data structures. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
111 lines
2.7 KiB
C
111 lines
2.7 KiB
C
/*
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* include/asm-s390/smp.h
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*
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* S390 version
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* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
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* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
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* Martin Schwidefsky (schwidefsky@de.ibm.com)
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* Heiko Carstens (heiko.carstens@de.ibm.com)
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*/
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#ifndef __ASM_SMP_H
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#define __ASM_SMP_H
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#include <linux/config.h>
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#include <linux/threads.h>
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#include <linux/cpumask.h>
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#include <linux/bitops.h>
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#if defined(__KERNEL__) && defined(CONFIG_SMP) && !defined(__ASSEMBLY__)
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#include <asm/lowcore.h>
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#include <asm/sigp.h>
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/*
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s390 specific smp.c headers
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*/
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typedef struct
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{
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int intresting;
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sigp_ccode ccode;
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__u32 status;
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__u16 cpu;
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} sigp_info;
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extern void smp_setup_cpu_possible_map(void);
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extern int smp_call_function_on(void (*func) (void *info), void *info,
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int nonatomic, int wait, int cpu);
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#define NO_PROC_ID 0xFF /* No processor magic marker */
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/*
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* This magic constant controls our willingness to transfer
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* a process across CPUs. Such a transfer incurs misses on the L1
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* cache, and on a P6 or P5 with multiple L2 caches L2 hits. My
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* gut feeling is this will vary by board in value. For a board
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* with separate L2 cache it probably depends also on the RSS, and
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* for a board with shared L2 cache it ought to decay fast as other
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* processes are run.
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*/
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#define PROC_CHANGE_PENALTY 20 /* Schedule penalty */
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#define raw_smp_processor_id() (S390_lowcore.cpu_data.cpu_nr)
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extern int smp_get_cpu(cpumask_t cpu_map);
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extern void smp_put_cpu(int cpu);
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static inline __u16 hard_smp_processor_id(void)
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{
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__u16 cpu_address;
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__asm__ ("stap %0\n" : "=m" (cpu_address));
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return cpu_address;
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}
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/*
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* returns 1 if cpu is in stopped/check stopped state or not operational
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* returns 0 otherwise
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*/
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static inline int
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smp_cpu_not_running(int cpu)
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{
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__u32 status;
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switch (signal_processor_ps(&status, 0, cpu, sigp_sense)) {
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case sigp_order_code_accepted:
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case sigp_status_stored:
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/* Check for stopped and check stop state */
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if (status & 0x50)
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return 1;
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break;
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case sigp_not_operational:
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return 1;
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default:
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break;
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}
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return 0;
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}
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#define cpu_logical_map(cpu) (cpu)
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extern int __cpu_disable (void);
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extern void __cpu_die (unsigned int cpu);
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extern void cpu_die (void) __attribute__ ((noreturn));
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extern int __cpu_up (unsigned int cpu);
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#endif
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#ifndef CONFIG_SMP
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static inline int
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smp_call_function_on(void (*func) (void *info), void *info,
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int nonatomic, int wait, int cpu)
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{
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func(info);
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return 0;
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}
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#define smp_cpu_not_running(cpu) 1
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#define smp_get_cpu(cpu) ({ 0; })
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#define smp_put_cpu(cpu) ({ 0; })
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#define smp_setup_cpu_possible_map()
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#endif
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#endif
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