From 858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 31 Jan 2017 04:09:35 +0100 Subject: timers/itimer: Convert internal cputime_t units to nsec Use the new nsec based cputime accessors as part of the whole cputime conversion from cputime_t to nsecs. Also convert itimers to use nsec based internal counters. This simplifies it and removes the whole game with error/inc_error which served to deal with cputime_t random granularity. Signed-off-by: Frederic Weisbecker Cc: Benjamin Herrenschmidt Cc: Fenghua Yu Cc: Heiko Carstens Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Rik van Riel Cc: Stanislaw Gruszka Cc: Thomas Gleixner Cc: Tony Luck Cc: Wanpeng Li Link: http://lkml.kernel.org/r/1485832191-26889-20-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar --- kernel/time/posix-cpu-timers.c | 43 +++++++++++++++++------------------------- 1 file changed, 17 insertions(+), 26 deletions(-) (limited to 'kernel/time/posix-cpu-timers.c') diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 45be3cec0dc2..b4377a5e4269 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -20,10 +20,10 @@ */ void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new) { - cputime_t cputime = secs_to_cputime(rlim_new); + u64 nsecs = rlim_new * NSEC_PER_SEC; spin_lock_irq(&task->sighand->siglock); - set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL); + set_process_cpu_timer(task, CPUCLOCK_PROF, &nsecs, NULL); spin_unlock_irq(&task->sighand->siglock); } @@ -860,17 +860,11 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, if (!it->expires) return; - if (cur_time >= cputime_to_nsecs(it->expires)) { - if (it->incr) { + if (cur_time >= it->expires) { + if (it->incr) it->expires += it->incr; - it->error += it->incr_error; - if (it->error >= TICK_NSEC) { - it->expires -= cputime_one_jiffy; - it->error -= TICK_NSEC; - } - } else { + else it->expires = 0; - } trace_itimer_expire(signo == SIGPROF ? ITIMER_PROF : ITIMER_VIRTUAL, @@ -878,9 +872,8 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); } - if (it->expires && (!*expires || cputime_to_nsecs(it->expires) < *expires)) { - *expires = cputime_to_nsecs(it->expires); - } + if (it->expires && (!*expires || it->expires < *expires)) + *expires = it->expires; } /* @@ -1174,9 +1167,9 @@ void run_posix_cpu_timers(struct task_struct *tsk) * The tsk->sighand->siglock must be held by the caller. */ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, - cputime_t *newval, cputime_t *oldval) + u64 *newval, u64 *oldval) { - u64 now, new; + u64 now; WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED); cpu_timer_sample_group(clock_idx, tsk, &now); @@ -1188,33 +1181,31 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, * it to be absolute. */ if (*oldval) { - if (cputime_to_nsecs(*oldval) <= now) { + if (*oldval <= now) { /* Just about to fire. */ - *oldval = cputime_one_jiffy; + *oldval = TICK_NSEC; } else { - *oldval -= nsecs_to_cputime(now); + *oldval -= now; } } if (!*newval) return; - *newval += nsecs_to_cputime(now); + *newval += now; } - new = cputime_to_nsecs(*newval); - /* * Update expiration cache if we are the earliest timer, or eventually * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire. */ switch (clock_idx) { case CPUCLOCK_PROF: - if (expires_gt(tsk->signal->cputime_expires.prof_exp, new)) - tsk->signal->cputime_expires.prof_exp = new; + if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval)) + tsk->signal->cputime_expires.prof_exp = *newval; break; case CPUCLOCK_VIRT: - if (expires_gt(tsk->signal->cputime_expires.virt_exp, new)) - tsk->signal->cputime_expires.virt_exp = new; + if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval)) + tsk->signal->cputime_expires.virt_exp = *newval; break; } -- cgit v1.2.3