diff options
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | kernel/itimer.c | 24 | ||||
| -rw-r--r-- | kernel/posix-cpu-timers.c | 20 |
3 files changed, 40 insertions, 6 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 3b3efaddd953..a069e65e8bb7 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -473,6 +473,8 @@ struct pacct_struct { struct cpu_itimer { cputime_t expires; cputime_t incr; + u32 error; + u32 incr_error; }; /** diff --git a/kernel/itimer.c b/kernel/itimer.c index 852c88ddd1f0..21adff7b2a17 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -42,7 +42,7 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer) } static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, - struct itimerval *value) + struct itimerval *const value) { cputime_t cval, cinterval; struct cpu_itimer *it = &tsk->signal->it[clock_id]; @@ -127,14 +127,32 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer) return HRTIMER_NORESTART; } +static inline u32 cputime_sub_ns(cputime_t ct, s64 real_ns) +{ + struct timespec ts; + s64 cpu_ns; + + cputime_to_timespec(ct, &ts); + cpu_ns = timespec_to_ns(&ts); + + return (cpu_ns <= real_ns) ? 0 : cpu_ns - real_ns; +} + static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, - struct itimerval *value, struct itimerval *ovalue) + const struct itimerval *const value, + struct itimerval *const ovalue) { - cputime_t cval, cinterval, nval, ninterval; + cputime_t cval, nval, cinterval, ninterval; + s64 ns_ninterval, ns_nval; struct cpu_itimer *it = &tsk->signal->it[clock_id]; nval = timeval_to_cputime(&value->it_value); + ns_nval = timeval_to_ns(&value->it_value); ninterval = timeval_to_cputime(&value->it_interval); + ns_ninterval = timeval_to_ns(&value->it_interval); + + it->incr_error = cputime_sub_ns(ninterval, ns_ninterval); + it->error = cputime_sub_ns(nval, ns_nval); spin_lock_irq(&tsk->sighand->siglock); diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 9b2d5e4dc8c4..b60d644ea4b3 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1070,6 +1070,8 @@ static void stop_process_timers(struct task_struct *tsk) spin_unlock_irqrestore(&cputimer->lock, flags); } +static u32 onecputick; + static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, cputime_t *expires, cputime_t cur_time, int signo) { @@ -1077,9 +1079,16 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, return; if (cputime_ge(cur_time, it->expires)) { - it->expires = it->incr; - if (!cputime_eq(it->expires, cputime_zero)) - it->expires = cputime_add(it->expires, cur_time); + if (!cputime_eq(it->incr, cputime_zero)) { + it->expires = cputime_add(it->expires, it->incr); + it->error += it->incr_error; + if (it->error >= onecputick) { + it->expires = cputime_sub(it->expires, + jiffies_to_cputime(1)); + it->error -= onecputick; + } + } else + it->expires = cputime_zero; __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); } @@ -1696,10 +1705,15 @@ static __init int init_posix_cpu_timers(void) .nsleep = thread_cpu_nsleep, .nsleep_restart = thread_cpu_nsleep_restart, }; + struct timespec ts; register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process); register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread); + cputime_to_timespec(jiffies_to_cputime(1), &ts); + onecputick = ts.tv_nsec; + WARN_ON(ts.tv_sec != 0); + return 0; } __initcall(init_posix_cpu_timers); |