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freescale-linux-fslc/include/linux/posix-timers.h
Frederic Weisbecker b78783000d posix-cpu-timers: Migrate to use new tick dependency mask model
Instead of providing asynchronous checks for the nohz subsystem to verify
posix cpu timers tick dependency, migrate the latter to the new mask.

In order to keep track of the running timers and expose the tick
dependency accordingly, we must probe the timers queuing and dequeuing
on threads and process lists.

Unfortunately it implies both task and signal level dependencies. We
should be able to further optimize this and merge all that on the task
level dependency, at the cost of a bit of complexity and may be overhead.

Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2016-03-02 16:44:27 +01:00

139 lines
4.2 KiB
C

#ifndef _linux_POSIX_TIMERS_H
#define _linux_POSIX_TIMERS_H
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/timex.h>
#include <linux/alarmtimer.h>
static inline unsigned long long cputime_to_expires(cputime_t expires)
{
return (__force unsigned long long)expires;
}
static inline cputime_t expires_to_cputime(unsigned long long expires)
{
return (__force cputime_t)expires;
}
struct cpu_timer_list {
struct list_head entry;
unsigned long long expires, incr;
struct task_struct *task;
int firing;
};
/*
* Bit fields within a clockid:
*
* The most significant 29 bits hold either a pid or a file descriptor.
*
* Bit 2 indicates whether a cpu clock refers to a thread or a process.
*
* Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
*
* A clockid is invalid if bits 2, 1, and 0 are all set.
*/
#define CPUCLOCK_PID(clock) ((pid_t) ~((clock) >> 3))
#define CPUCLOCK_PERTHREAD(clock) \
(((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
#define CPUCLOCK_PERTHREAD_MASK 4
#define CPUCLOCK_WHICH(clock) ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
#define CPUCLOCK_CLOCK_MASK 3
#define CPUCLOCK_PROF 0
#define CPUCLOCK_VIRT 1
#define CPUCLOCK_SCHED 2
#define CPUCLOCK_MAX 3
#define CLOCKFD CPUCLOCK_MAX
#define CLOCKFD_MASK (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)
#define MAKE_PROCESS_CPUCLOCK(pid, clock) \
((~(clockid_t) (pid) << 3) | (clockid_t) (clock))
#define MAKE_THREAD_CPUCLOCK(tid, clock) \
MAKE_PROCESS_CPUCLOCK((tid), (clock) | CPUCLOCK_PERTHREAD_MASK)
#define FD_TO_CLOCKID(fd) ((~(clockid_t) (fd) << 3) | CLOCKFD)
#define CLOCKID_TO_FD(clk) ((unsigned int) ~((clk) >> 3))
/* POSIX.1b interval timer structure. */
struct k_itimer {
struct list_head list; /* free/ allocate list */
struct hlist_node t_hash;
spinlock_t it_lock;
clockid_t it_clock; /* which timer type */
timer_t it_id; /* timer id */
int it_overrun; /* overrun on pending signal */
int it_overrun_last; /* overrun on last delivered signal */
int it_requeue_pending; /* waiting to requeue this timer */
#define REQUEUE_PENDING 1
int it_sigev_notify; /* notify word of sigevent struct */
struct signal_struct *it_signal;
union {
struct pid *it_pid; /* pid of process to send signal to */
struct task_struct *it_process; /* for clock_nanosleep */
};
struct sigqueue *sigq; /* signal queue entry. */
union {
struct {
struct hrtimer timer;
ktime_t interval;
} real;
struct cpu_timer_list cpu;
struct {
unsigned int clock;
unsigned int node;
unsigned long incr;
unsigned long expires;
} mmtimer;
struct {
struct alarm alarmtimer;
ktime_t interval;
} alarm;
struct rcu_head rcu;
} it;
};
struct k_clock {
int (*clock_getres) (const clockid_t which_clock, struct timespec *tp);
int (*clock_set) (const clockid_t which_clock,
const struct timespec *tp);
int (*clock_get) (const clockid_t which_clock, struct timespec * tp);
int (*clock_adj) (const clockid_t which_clock, struct timex *tx);
int (*timer_create) (struct k_itimer *timer);
int (*nsleep) (const clockid_t which_clock, int flags,
struct timespec *, struct timespec __user *);
long (*nsleep_restart) (struct restart_block *restart_block);
int (*timer_set) (struct k_itimer * timr, int flags,
struct itimerspec * new_setting,
struct itimerspec * old_setting);
int (*timer_del) (struct k_itimer * timr);
#define TIMER_RETRY 1
void (*timer_get) (struct k_itimer * timr,
struct itimerspec * cur_setting);
};
extern struct k_clock clock_posix_cpu;
extern struct k_clock clock_posix_dynamic;
void posix_timers_register_clock(const clockid_t clock_id, struct k_clock *new_clock);
/* function to call to trigger timer event */
int posix_timer_event(struct k_itimer *timr, int si_private);
void posix_cpu_timer_schedule(struct k_itimer *timer);
void run_posix_cpu_timers(struct task_struct *task);
void posix_cpu_timers_exit(struct task_struct *task);
void posix_cpu_timers_exit_group(struct task_struct *task);
void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
cputime_t *newval, cputime_t *oldval);
long clock_nanosleep_restart(struct restart_block *restart_block);
void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
#endif