39c715b717
This patch implements a number of smp_processor_id() cleanup ideas that
Arjan van de Ven and I came up with.
The previous __smp_processor_id/_smp_processor_id/smp_processor_id API
spaghetti was hard to follow both on the implementational and on the
usage side.
Some of the complexity arose from picking wrong names, some of the
complexity comes from the fact that not all architectures defined
__smp_processor_id.
In the new code, there are two externally visible symbols:
- smp_processor_id(): debug variant.
- raw_smp_processor_id(): nondebug variant. Replaces all existing
uses of _smp_processor_id() and __smp_processor_id(). Defined
by every SMP architecture in include/asm-*/smp.h.
There is one new internal symbol, dependent on DEBUG_PREEMPT:
- debug_smp_processor_id(): internal debug variant, mapped to
smp_processor_id().
Also, i moved debug_smp_processor_id() from lib/kernel_lock.c into a new
lib/smp_processor_id.c file. All related comments got updated and/or
clarified.
I have build/boot tested the following 8 .config combinations on x86:
{SMP,UP} x {PREEMPT,!PREEMPT} x {DEBUG_PREEMPT,!DEBUG_PREEMPT}
I have also build/boot tested x64 on UP/PREEMPT/DEBUG_PREEMPT. (Other
architectures are untested, but should work just fine.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
108 lines
2.6 KiB
C
108 lines
2.6 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 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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extern __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_get_cpu(cpu) ({ 0; })
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#define smp_put_cpu(cpu) ({ 0; })
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#endif
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#endif
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