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27f6b41662
The current virtual timer interface is inherently per-cpu and hard to use. The sole user of the interface is appldata which uses it to execute a function after a specific amount of cputime has been used over all cpus. Rework the virtual timer interface to hook into the cputime accounting. This makes the interface independent from the CPU timer interrupts, and makes the virtual timers global as opposed to per-cpu. Overall the code is greatly simplified. The downside is that the accuracy is not as good as the original implementation, but it is still good enough for appldata. Reviewed-by: Jan Glauber <jang@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
191 lines
4.7 KiB
C
191 lines
4.7 KiB
C
/*
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* Copyright IBM Corp. 2004
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*
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* Author: Martin Schwidefsky <schwidefsky@de.ibm.com>
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*/
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#ifndef _S390_CPUTIME_H
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#define _S390_CPUTIME_H
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#include <linux/types.h>
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#include <linux/percpu.h>
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#include <linux/spinlock.h>
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#include <asm/div64.h>
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/* We want to use full resolution of the CPU timer: 2**-12 micro-seconds. */
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typedef unsigned long long __nocast cputime_t;
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typedef unsigned long long __nocast cputime64_t;
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static inline unsigned long __div(unsigned long long n, unsigned long base)
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{
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#ifndef CONFIG_64BIT
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register_pair rp;
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rp.pair = n >> 1;
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asm ("dr %0,%1" : "+d" (rp) : "d" (base >> 1));
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return rp.subreg.odd;
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#else /* CONFIG_64BIT */
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return n / base;
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#endif /* CONFIG_64BIT */
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}
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#define cputime_one_jiffy jiffies_to_cputime(1)
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/*
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* Convert cputime to jiffies and back.
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*/
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static inline unsigned long cputime_to_jiffies(const cputime_t cputime)
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{
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return __div((__force unsigned long long) cputime, 4096000000ULL / HZ);
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}
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static inline cputime_t jiffies_to_cputime(const unsigned int jif)
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{
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return (__force cputime_t)(jif * (4096000000ULL / HZ));
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}
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static inline u64 cputime64_to_jiffies64(cputime64_t cputime)
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{
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unsigned long long jif = (__force unsigned long long) cputime;
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do_div(jif, 4096000000ULL / HZ);
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return jif;
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}
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static inline cputime64_t jiffies64_to_cputime64(const u64 jif)
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{
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return (__force cputime64_t)(jif * (4096000000ULL / HZ));
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}
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/*
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* Convert cputime to microseconds and back.
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*/
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static inline unsigned int cputime_to_usecs(const cputime_t cputime)
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{
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return (__force unsigned long long) cputime >> 12;
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}
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static inline cputime_t usecs_to_cputime(const unsigned int m)
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{
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return (__force cputime_t)(m * 4096ULL);
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}
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#define usecs_to_cputime64(m) usecs_to_cputime(m)
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/*
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* Convert cputime to milliseconds and back.
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*/
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static inline unsigned int cputime_to_secs(const cputime_t cputime)
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{
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return __div((__force unsigned long long) cputime, 2048000000) >> 1;
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}
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static inline cputime_t secs_to_cputime(const unsigned int s)
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{
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return (__force cputime_t)(s * 4096000000ULL);
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}
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/*
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* Convert cputime to timespec and back.
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*/
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static inline cputime_t timespec_to_cputime(const struct timespec *value)
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{
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unsigned long long ret = value->tv_sec * 4096000000ULL;
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return (__force cputime_t)(ret + value->tv_nsec * 4096 / 1000);
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}
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static inline void cputime_to_timespec(const cputime_t cputime,
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struct timespec *value)
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{
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unsigned long long __cputime = (__force unsigned long long) cputime;
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#ifndef CONFIG_64BIT
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register_pair rp;
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rp.pair = __cputime >> 1;
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asm ("dr %0,%1" : "+d" (rp) : "d" (2048000000UL));
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value->tv_nsec = rp.subreg.even * 1000 / 4096;
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value->tv_sec = rp.subreg.odd;
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#else
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value->tv_nsec = (__cputime % 4096000000ULL) * 1000 / 4096;
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value->tv_sec = __cputime / 4096000000ULL;
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#endif
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}
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/*
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* Convert cputime to timeval and back.
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* Since cputime and timeval have the same resolution (microseconds)
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* this is easy.
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*/
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static inline cputime_t timeval_to_cputime(const struct timeval *value)
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{
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unsigned long long ret = value->tv_sec * 4096000000ULL;
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return (__force cputime_t)(ret + value->tv_usec * 4096ULL);
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}
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static inline void cputime_to_timeval(const cputime_t cputime,
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struct timeval *value)
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{
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unsigned long long __cputime = (__force unsigned long long) cputime;
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#ifndef CONFIG_64BIT
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register_pair rp;
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rp.pair = __cputime >> 1;
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asm ("dr %0,%1" : "+d" (rp) : "d" (2048000000UL));
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value->tv_usec = rp.subreg.even / 4096;
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value->tv_sec = rp.subreg.odd;
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#else
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value->tv_usec = (__cputime % 4096000000ULL) / 4096;
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value->tv_sec = __cputime / 4096000000ULL;
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#endif
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}
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/*
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* Convert cputime to clock and back.
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*/
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static inline clock_t cputime_to_clock_t(cputime_t cputime)
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{
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unsigned long long clock = (__force unsigned long long) cputime;
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do_div(clock, 4096000000ULL / USER_HZ);
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return clock;
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}
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static inline cputime_t clock_t_to_cputime(unsigned long x)
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{
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return (__force cputime_t)(x * (4096000000ULL / USER_HZ));
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}
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/*
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* Convert cputime64 to clock.
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*/
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static inline clock_t cputime64_to_clock_t(cputime64_t cputime)
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{
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unsigned long long clock = (__force unsigned long long) cputime;
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do_div(clock, 4096000000ULL / USER_HZ);
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return clock;
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}
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struct s390_idle_data {
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int nohz_delay;
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unsigned int sequence;
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unsigned long long idle_count;
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unsigned long long idle_time;
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unsigned long long clock_idle_enter;
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unsigned long long clock_idle_exit;
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unsigned long long timer_idle_enter;
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unsigned long long timer_idle_exit;
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};
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DECLARE_PER_CPU(struct s390_idle_data, s390_idle);
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cputime64_t s390_get_idle_time(int cpu);
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#define arch_idle_time(cpu) s390_get_idle_time(cpu)
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static inline int s390_nohz_delay(int cpu)
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{
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return __get_cpu_var(s390_idle).nohz_delay != 0;
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}
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#define arch_needs_cpu(cpu) s390_nohz_delay(cpu)
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#endif /* _S390_CPUTIME_H */
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