From 648616343cdbe904c585a6c12e323d3b3c72e46f Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 15 Dec 2011 14:56:09 +0100 Subject: [S390] cputime: add sparse checking and cleanup Make cputime_t and cputime64_t nocast to enable sparse checking to detect incorrect use of cputime. Drop the cputime macros for simple scalar operations. The conversion macros are still needed. Signed-off-by: Martin Schwidefsky --- kernel/posix-cpu-timers.c | 132 ++++++++++++++++++---------------------------- 1 file changed, 52 insertions(+), 80 deletions(-) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index e7cb76dc18f..125cb67daa2 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -78,7 +78,7 @@ static inline int cpu_time_before(const clockid_t which_clock, if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { return now.sched < then.sched; } else { - return cputime_lt(now.cpu, then.cpu); + return now.cpu < then.cpu; } } static inline void cpu_time_add(const clockid_t which_clock, @@ -88,7 +88,7 @@ static inline void cpu_time_add(const clockid_t which_clock, if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { acc->sched += val.sched; } else { - acc->cpu = cputime_add(acc->cpu, val.cpu); + acc->cpu += val.cpu; } } static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock, @@ -98,24 +98,11 @@ static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock, if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { a.sched -= b.sched; } else { - a.cpu = cputime_sub(a.cpu, b.cpu); + a.cpu -= b.cpu; } return a; } -/* - * Divide and limit the result to res >= 1 - * - * This is necessary to prevent signal delivery starvation, when the result of - * the division would be rounded down to 0. - */ -static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div) -{ - cputime_t res = cputime_div(time, div); - - return max_t(cputime_t, res, 1); -} - /* * Update expiry time from increment, and increase overrun count, * given the current clock sample. @@ -148,28 +135,26 @@ static void bump_cpu_timer(struct k_itimer *timer, } else { cputime_t delta, incr; - if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu)) + if (now.cpu < timer->it.cpu.expires.cpu) return; incr = timer->it.cpu.incr.cpu; - delta = cputime_sub(cputime_add(now.cpu, incr), - timer->it.cpu.expires.cpu); + delta = now.cpu + incr - timer->it.cpu.expires.cpu; /* Don't use (incr*2 < delta), incr*2 might overflow. */ - for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++) - incr = cputime_add(incr, incr); - for (; i >= 0; incr = cputime_halve(incr), i--) { - if (cputime_lt(delta, incr)) + for (i = 0; incr < delta - incr; i++) + incr += incr; + for (; i >= 0; incr = incr >> 1, i--) { + if (delta < incr) continue; - timer->it.cpu.expires.cpu = - cputime_add(timer->it.cpu.expires.cpu, incr); + timer->it.cpu.expires.cpu += incr; timer->it_overrun += 1 << i; - delta = cputime_sub(delta, incr); + delta -= incr; } } } static inline cputime_t prof_ticks(struct task_struct *p) { - return cputime_add(p->utime, p->stime); + return p->utime + p->stime; } static inline cputime_t virt_ticks(struct task_struct *p) { @@ -248,8 +233,8 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) t = tsk; do { - times->utime = cputime_add(times->utime, t->utime); - times->stime = cputime_add(times->stime, t->stime); + times->utime += t->utime; + times->stime += t->stime; times->sum_exec_runtime += task_sched_runtime(t); } while_each_thread(tsk, t); out: @@ -258,10 +243,10 @@ out: static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b) { - if (cputime_gt(b->utime, a->utime)) + if (b->utime > a->utime) a->utime = b->utime; - if (cputime_gt(b->stime, a->stime)) + if (b->stime > a->stime) a->stime = b->stime; if (b->sum_exec_runtime > a->sum_exec_runtime) @@ -306,7 +291,7 @@ static int cpu_clock_sample_group(const clockid_t which_clock, return -EINVAL; case CPUCLOCK_PROF: thread_group_cputime(p, &cputime); - cpu->cpu = cputime_add(cputime.utime, cputime.stime); + cpu->cpu = cputime.utime + cputime.stime; break; case CPUCLOCK_VIRT: thread_group_cputime(p, &cputime); @@ -470,26 +455,24 @@ static void cleanup_timers(struct list_head *head, unsigned long long sum_exec_runtime) { struct cpu_timer_list *timer, *next; - cputime_t ptime = cputime_add(utime, stime); + cputime_t ptime = utime + stime; list_for_each_entry_safe(timer, next, head, entry) { list_del_init(&timer->entry); - if (cputime_lt(timer->expires.cpu, ptime)) { - timer->expires.cpu = cputime_zero; + if (timer->expires.cpu < ptime) { + timer->expires.cpu = 0; } else { - timer->expires.cpu = cputime_sub(timer->expires.cpu, - ptime); + timer->expires.cpu -= ptime; } } ++head; list_for_each_entry_safe(timer, next, head, entry) { list_del_init(&timer->entry); - if (cputime_lt(timer->expires.cpu, utime)) { - timer->expires.cpu = cputime_zero; + if (timer->expires.cpu < utime) { + timer->expires.cpu = 0; } else { - timer->expires.cpu = cputime_sub(timer->expires.cpu, - utime); + timer->expires.cpu -= utime; } } @@ -520,8 +503,7 @@ void posix_cpu_timers_exit_group(struct task_struct *tsk) struct signal_struct *const sig = tsk->signal; cleanup_timers(tsk->signal->cpu_timers, - cputime_add(tsk->utime, sig->utime), - cputime_add(tsk->stime, sig->stime), + tsk->utime + sig->utime, tsk->stime + sig->stime, tsk->se.sum_exec_runtime + sig->sum_sched_runtime); } @@ -540,8 +522,7 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now) static inline int expires_gt(cputime_t expires, cputime_t new_exp) { - return cputime_eq(expires, cputime_zero) || - cputime_gt(expires, new_exp); + return expires == 0 || expires > new_exp; } /* @@ -651,7 +632,7 @@ static int cpu_timer_sample_group(const clockid_t which_clock, default: return -EINVAL; case CPUCLOCK_PROF: - cpu->cpu = cputime_add(cputime.utime, cputime.stime); + cpu->cpu = cputime.utime + cputime.stime; break; case CPUCLOCK_VIRT: cpu->cpu = cputime.utime; @@ -918,12 +899,12 @@ static void check_thread_timers(struct task_struct *tsk, unsigned long soft; maxfire = 20; - tsk->cputime_expires.prof_exp = cputime_zero; + tsk->cputime_expires.prof_exp = 0; while (!list_empty(timers)) { struct cpu_timer_list *t = list_first_entry(timers, struct cpu_timer_list, entry); - if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) { + if (!--maxfire || prof_ticks(tsk) < t->expires.cpu) { tsk->cputime_expires.prof_exp = t->expires.cpu; break; } @@ -933,12 +914,12 @@ static void check_thread_timers(struct task_struct *tsk, ++timers; maxfire = 20; - tsk->cputime_expires.virt_exp = cputime_zero; + tsk->cputime_expires.virt_exp = 0; while (!list_empty(timers)) { struct cpu_timer_list *t = list_first_entry(timers, struct cpu_timer_list, entry); - if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) { + if (!--maxfire || virt_ticks(tsk) < t->expires.cpu) { tsk->cputime_expires.virt_exp = t->expires.cpu; break; } @@ -1009,20 +990,19 @@ 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) { - if (cputime_eq(it->expires, cputime_zero)) + if (!it->expires) return; - if (cputime_ge(cur_time, it->expires)) { - if (!cputime_eq(it->incr, cputime_zero)) { - it->expires = cputime_add(it->expires, it->incr); + if (cur_time >= it->expires) { + if (it->incr) { + it->expires += it->incr; it->error += it->incr_error; if (it->error >= onecputick) { - it->expires = cputime_sub(it->expires, - cputime_one_jiffy); + it->expires -= cputime_one_jiffy; it->error -= onecputick; } } else { - it->expires = cputime_zero; + it->expires = 0; } trace_itimer_expire(signo == SIGPROF ? @@ -1031,9 +1011,7 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); } - if (!cputime_eq(it->expires, cputime_zero) && - (cputime_eq(*expires, cputime_zero) || - cputime_lt(it->expires, *expires))) { + if (it->expires && (!*expires || it->expires < *expires)) { *expires = it->expires; } } @@ -1048,9 +1026,7 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, */ static inline int task_cputime_zero(const struct task_cputime *cputime) { - if (cputime_eq(cputime->utime, cputime_zero) && - cputime_eq(cputime->stime, cputime_zero) && - cputime->sum_exec_runtime == 0) + if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime) return 1; return 0; } @@ -1076,15 +1052,15 @@ static void check_process_timers(struct task_struct *tsk, */ thread_group_cputimer(tsk, &cputime); utime = cputime.utime; - ptime = cputime_add(utime, cputime.stime); + ptime = utime + cputime.stime; sum_sched_runtime = cputime.sum_exec_runtime; maxfire = 20; - prof_expires = cputime_zero; + prof_expires = 0; while (!list_empty(timers)) { struct cpu_timer_list *tl = list_first_entry(timers, struct cpu_timer_list, entry); - if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) { + if (!--maxfire || ptime < tl->expires.cpu) { prof_expires = tl->expires.cpu; break; } @@ -1094,12 +1070,12 @@ static void check_process_timers(struct task_struct *tsk, ++timers; maxfire = 20; - virt_expires = cputime_zero; + virt_expires = 0; while (!list_empty(timers)) { struct cpu_timer_list *tl = list_first_entry(timers, struct cpu_timer_list, entry); - if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) { + if (!--maxfire || utime < tl->expires.cpu) { virt_expires = tl->expires.cpu; break; } @@ -1154,8 +1130,7 @@ static void check_process_timers(struct task_struct *tsk, } } x = secs_to_cputime(soft); - if (cputime_eq(prof_expires, cputime_zero) || - cputime_lt(x, prof_expires)) { + if (!prof_expires || x < prof_expires) { prof_expires = x; } } @@ -1249,12 +1224,9 @@ out: static inline int task_cputime_expired(const struct task_cputime *sample, const struct task_cputime *expires) { - if (!cputime_eq(expires->utime, cputime_zero) && - cputime_ge(sample->utime, expires->utime)) + if (expires->utime && sample->utime >= expires->utime) return 1; - if (!cputime_eq(expires->stime, cputime_zero) && - cputime_ge(cputime_add(sample->utime, sample->stime), - expires->stime)) + if (expires->stime && sample->utime + sample->stime >= expires->stime) return 1; if (expires->sum_exec_runtime != 0 && sample->sum_exec_runtime >= expires->sum_exec_runtime) @@ -1389,18 +1361,18 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, * it to be relative, *newval argument is relative and we update * it to be absolute. */ - if (!cputime_eq(*oldval, cputime_zero)) { - if (cputime_le(*oldval, now.cpu)) { + if (*oldval) { + if (*oldval <= now.cpu) { /* Just about to fire. */ *oldval = cputime_one_jiffy; } else { - *oldval = cputime_sub(*oldval, now.cpu); + *oldval -= now.cpu; } } - if (cputime_eq(*newval, cputime_zero)) + if (!*newval) return; - *newval = cputime_add(*newval, now.cpu); + *newval += now.cpu; } /* -- cgit v1.2.3