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Commit b18b6a9c authored by Nicolas Pitre's avatar Nicolas Pitre Committed by John Stultz
Browse files

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: default avatarNicolas Pitre <nico@linaro.org>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 9f819798

fs/proc/base.c

+2 −2
Original line number Diff line number Diff line
@@ -2179,7 +2179,7 @@ static const struct file_operations proc_map_files_operations = { 
	.llseek		= generic_file_llseek,

};



#ifdef CONFIG_CHECKPOINT_RESTORE

#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)

struct timers_private {

	struct pid *pid;

	struct task_struct *task;
@@ -2936,7 +2936,7 @@ static const struct pid_entry tgid_base_stuff[] = { 
	REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),

	REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),

#endif

#ifdef CONFIG_CHECKPOINT_RESTORE

#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)

	REG("timers",	  S_IRUGO, proc_timers_operations),

#endif

	REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),

include/linux/init_task.h

+25 −15
Original line number Diff line number Diff line
@@ -42,6 +42,27 @@ extern struct fs_struct init_fs; 
#define INIT_PREV_CPUTIME(x)

#endif



#ifdef CONFIG_POSIX_TIMERS

#define INIT_POSIX_TIMERS(s)						\

	.posix_timers = LIST_HEAD_INIT(s.posix_timers),

#define INIT_CPU_TIMERS(s)						\

	.cpu_timers = {							\

		LIST_HEAD_INIT(s.cpu_timers[0]),			\

		LIST_HEAD_INIT(s.cpu_timers[1]),			\

		LIST_HEAD_INIT(s.cpu_timers[2]),								\

	},

#define INIT_CPUTIMER(s)						\

	.cputimer	= { 						\

		.cputime_atomic	= INIT_CPUTIME_ATOMIC,			\

		.running	= false,				\

		.checking_timer = false,				\

	},

#else

#define INIT_POSIX_TIMERS(s)

#define INIT_CPU_TIMERS(s)

#define INIT_CPUTIMER(s)

#endif



#define INIT_SIGNALS(sig) {						\

	.nr_threads	= 1,						\

	.thread_head	= LIST_HEAD_INIT(init_task.thread_node),	\
@@ -49,14 +70,10 @@ extern struct fs_struct init_fs; 
	.shared_pending	= { 						\

		.list = LIST_HEAD_INIT(sig.shared_pending.list),	\

		.signal =  {{0}}},					\

	.posix_timers	 = LIST_HEAD_INIT(sig.posix_timers),		\

	.cpu_timers	= INIT_CPU_TIMERS(sig.cpu_timers),		\

	INIT_POSIX_TIMERS(sig)						\

	INIT_CPU_TIMERS(sig)						\

	.rlim		= INIT_RLIMITS,					\

	.cputimer	= { 						\

		.cputime_atomic	= INIT_CPUTIME_ATOMIC,			\

		.running	= false,				\

		.checking_timer = false,				\

	},								\

	INIT_CPUTIMER(sig)						\

	INIT_PREV_CPUTIME(sig)						\

	.cred_guard_mutex =						\

		 __MUTEX_INITIALIZER(sig.cred_guard_mutex),		\
@@ -247,7 +264,7 @@ extern struct task_group root_task_group; 
	.blocked	= {{0}},					\

	.alloc_lock	= __SPIN_LOCK_UNLOCKED(tsk.alloc_lock),		\

	.journal_info	= NULL,						\

	.cpu_timers	= INIT_CPU_TIMERS(tsk.cpu_timers),		\

	INIT_CPU_TIMERS(tsk)						\

	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock),	\

	.timer_slack_ns = 50000, /* 50 usec default slack */		\

	.pids = {							\
@@ -274,13 +291,6 @@ extern struct task_group root_task_group; 
}





#define INIT_CPU_TIMERS(cpu_timers)					\

{									\

	LIST_HEAD_INIT(cpu_timers[0]),					\

	LIST_HEAD_INIT(cpu_timers[1]),					\

	LIST_HEAD_INIT(cpu_timers[2]),					\

}



/* Attach to the init_task data structure for proper alignment */

#define __init_task_data __attribute__((__section__(".data..init_task")))

include/linux/sched.h

+10 −3
Original line number Diff line number Diff line
@@ -734,13 +734,14 @@ struct signal_struct { 
	unsigned int		is_child_subreaper:1;

	unsigned int		has_child_subreaper:1;



#ifdef CONFIG_POSIX_TIMERS



	/* POSIX.1b Interval Timers */

	int			posix_timer_id;

	struct list_head	posix_timers;



	/* ITIMER_REAL timer for the process */

	struct hrtimer real_timer;

	struct pid *leader_pid;

	ktime_t it_real_incr;



	/*
@@ -759,12 +760,16 @@ struct signal_struct { 
	/* Earliest-expiration cache. */

	struct task_cputime cputime_expires;



	struct list_head cpu_timers[3];



#endif



	struct pid *leader_pid;



#ifdef CONFIG_NO_HZ_FULL

	atomic_t tick_dep_mask;

#endif



	struct list_head cpu_timers[3];



	struct pid *tty_old_pgrp;



	/* boolean value for session group leader */
@@ -1681,8 +1686,10 @@ struct task_struct { 
/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */

	unsigned long min_flt, maj_flt;



#ifdef CONFIG_POSIX_TIMERS

	struct task_cputime cputime_expires;

	struct list_head cpu_timers[3];

#endif



/* process credentials */

	const struct cred __rcu *ptracer_cred; /* Tracer's credentials at attach */

kernel/fork.c

+9 −1
Original line number Diff line number Diff line
@@ -1304,6 +1304,7 @@ void __cleanup_sighand(struct sighand_struct *sighand) 
	}

}



#ifdef CONFIG_POSIX_TIMERS

/*

 * Initialize POSIX timer handling for a thread group.

 */
@@ -1322,6 +1323,9 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig) 
	INIT_LIST_HEAD(&sig->cpu_timers[1]);

	INIT_LIST_HEAD(&sig->cpu_timers[2]);

}

#else

static inline void posix_cpu_timers_init_group(struct signal_struct *sig) { }

#endif



static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)

{
@@ -1346,11 +1350,11 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) 
	init_waitqueue_head(&sig->wait_chldexit);

	sig->curr_target = tsk;

	init_sigpending(&sig->shared_pending);

	INIT_LIST_HEAD(&sig->posix_timers);

	seqlock_init(&sig->stats_lock);

	prev_cputime_init(&sig->prev_cputime);



#ifdef CONFIG_POSIX_TIMERS

	INIT_LIST_HEAD(&sig->posix_timers);

	hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);

	sig->real_timer.function = it_real_fn;

#endif
@@ -1425,6 +1429,7 @@ static void rt_mutex_init_task(struct task_struct *p) 
#endif

}



#ifdef CONFIG_POSIX_TIMERS

/*

 * Initialize POSIX timer handling for a single task.

 */
@@ -1437,6 +1442,9 @@ static void posix_cpu_timers_init(struct task_struct *tsk) 
	INIT_LIST_HEAD(&tsk->cpu_timers[1]);

	INIT_LIST_HEAD(&tsk->cpu_timers[2]);

}

#else

static inline void posix_cpu_timers_init(struct task_struct *tsk) { }

#endif



static inline void

init_task_pid(struct task_struct *task, enum pid_type type, struct pid *pid)

kernel/sched/rt.c

+4 −0
Original line number Diff line number Diff line
@@ -2246,6 +2246,7 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) 
	}

}



#ifdef CONFIG_POSIX_TIMERS

static void watchdog(struct rq *rq, struct task_struct *p)

{

	unsigned long soft, hard;
@@ -2267,6 +2268,9 @@ static void watchdog(struct rq *rq, struct task_struct *p) 
			p->cputime_expires.sched_exp = p->se.sum_exec_runtime;

	}

}

#else

static inline void watchdog(struct rq *rq, struct task_struct *p) { }

#endif



static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)

{