From b18b6a9cef7f30e9a8b7738d5fc8d568cf660855 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Sat, 21 Jan 2017 00:09:08 -0500 Subject: timers: Omit POSIX timer stuff from task_struct when disabled When CONFIG_POSIX_TIMERS is disabled, it is preferable to remove related structures from struct task_struct and struct signal_struct as they won't contain anything useful and shouldn't be relied upon by mistake. Code still referencing those structures is also disabled here. Signed-off-by: Nicolas Pitre Signed-off-by: John Stultz --- kernel/sched/stats.h | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) (limited to 'kernel/sched/stats.h') diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h index 34659a853505..c69a9870ab79 100644 --- a/kernel/sched/stats.h +++ b/kernel/sched/stats.h @@ -172,18 +172,19 @@ sched_info_switch(struct rq *rq, */ /** - * cputimer_running - return true if cputimer is running + * get_running_cputimer - return &tsk->signal->cputimer if cputimer is running * * @tsk: Pointer to target task. */ -static inline bool cputimer_running(struct task_struct *tsk) - +#ifdef CONFIG_POSIX_TIMERS +static inline +struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk) { struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; /* Check if cputimer isn't running. This is accessed without locking. */ if (!READ_ONCE(cputimer->running)) - return false; + return NULL; /* * After we flush the task's sum_exec_runtime to sig->sum_sched_runtime @@ -200,10 +201,17 @@ static inline bool cputimer_running(struct task_struct *tsk) * clock delta is behind the expiring timer value. */ if (unlikely(!tsk->sighand)) - return false; + return NULL; - return true; + return cputimer; +} +#else +static inline +struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk) +{ + return NULL; } +#endif /** * account_group_user_time - Maintain utime for a thread group. @@ -218,9 +226,9 @@ static inline bool cputimer_running(struct task_struct *tsk) static inline void account_group_user_time(struct task_struct *tsk, cputime_t cputime) { - struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; + struct thread_group_cputimer *cputimer = get_running_cputimer(tsk); - if (!cputimer_running(tsk)) + if (!cputimer) return; atomic64_add(cputime, &cputimer->cputime_atomic.utime); @@ -239,9 +247,9 @@ static inline void account_group_user_time(struct task_struct *tsk, static inline void account_group_system_time(struct task_struct *tsk, cputime_t cputime) { - struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; + struct thread_group_cputimer *cputimer = get_running_cputimer(tsk); - if (!cputimer_running(tsk)) + if (!cputimer) return; atomic64_add(cputime, &cputimer->cputime_atomic.stime); @@ -260,9 +268,9 @@ static inline void account_group_system_time(struct task_struct *tsk, static inline void account_group_exec_runtime(struct task_struct *tsk, unsigned long long ns) { - struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; + struct thread_group_cputimer *cputimer = get_running_cputimer(tsk); - if (!cputimer_running(tsk)) + if (!cputimer) return; atomic64_add(ns, &cputimer->cputime_atomic.sum_exec_runtime); -- cgit v1.2.3