[PATCH] hrtimers: remove data field

The nanosleep cleanup allows to remove the data field of hrtimer.  The
callback function can use container_of() to get it's own data.  Since the
hrtimer structure is anyway embedded in other structures, this adds no
overhead.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

8 files changed, 22 insertions, 27 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 995cba3c62b8..c7397c46ad6d 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -632,7 +632,7 @@ static int de_thread(struct task_struct *tsk)
                  * synchronize with any firing (by calling del_timer_sync)
                  * before we can safely let the old group leader die.
                  */
-                sig->real_timer.data = current;
+                sig->tsk = current;
                 spin_unlock_irq(lock);
                 if (hrtimer_cancel(&sig->real_timer))
                         hrtimer_restart(&sig->real_timer);
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index f57cc7bd7008..93830158348e 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -45,9 +45,7 @@ struct hrtimer_base;
  * @expires:    the absolute expiry time in the hrtimers internal
  *              representation. The time is related to the clock on
  *              which the timer is based.
- * @state:      state of the timer
  * @function:   timer expiry callback function
- * @data:       argument for the callback function
  * @base:       pointer to the timer base (per cpu and per clock)
  *
  * The hrtimer structure must be initialized by init_hrtimer_#CLOCKTYPE()
@@ -55,8 +53,7 @@ struct hrtimer_base;
 struct hrtimer {
         struct rb_node          node;
         ktime_t                 expires;
-        int                     (*function)(void *);
-        void                    *data;
+        int                     (*function)(struct hrtimer *);
         struct hrtimer_base     *base;
 };
 
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e0054c1b9a09..036d14d2bf90 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -402,6 +402,7 @@ struct signal_struct {
 
         /* ITIMER_REAL timer for the process */
         struct hrtimer real_timer;
+        struct task_struct *tsk;
         ktime_t it_real_incr;
 
         /* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
diff --git a/include/linux/timer.h b/include/linux/timer.h
index ee5a09e806e8..b5caabca553c 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -96,6 +96,7 @@ static inline void add_timer(struct timer_list *timer)
 
 extern void init_timers(void);
 extern void run_local_timers(void);
-extern int it_real_fn(void *);
+struct hrtimer;
+extern int it_real_fn(struct hrtimer *);
 
 #endif
diff --git a/kernel/fork.c b/kernel/fork.c
index a02063903aaa..4bd6486aa67d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -848,7 +848,7 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts
         hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_REL);
         sig->it_real_incr.tv64 = 0;
         sig->real_timer.function = it_real_fn;
-        sig->real_timer.data = tsk;
+        sig->tsk = tsk;
 
         sig->it_virt_expires = cputime_zero;
         sig->it_virt_incr = cputime_zero;
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 44108de4f028..0237a556eb1f 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -613,21 +613,19 @@ static inline void run_hrtimer_queue(struct hrtimer_base *base)
 
         while ((node = base->first)) {
                 struct hrtimer *timer;
-                int (*fn)(void *);
+                int (*fn)(struct hrtimer *);
                 int restart;
-                void *data;
 
                 timer = rb_entry(node, struct hrtimer, node);
                 if (base->softirq_time.tv64 <= timer->expires.tv64)
                         break;
 
                 fn = timer->function;
-                data = timer->data;
                 set_curr_timer(base, timer);
                 __remove_hrtimer(timer, base);
                 spin_unlock_irq(&base->lock);
 
-                restart = fn(data);
+                restart = fn(timer);
 
                 spin_lock_irq(&base->lock);
 
@@ -664,9 +662,10 @@ struct sleep_hrtimer {
         int expired;
 };
 
-static int nanosleep_wakeup(void *data)
+static int nanosleep_wakeup(struct hrtimer *timer)
 {
-        struct sleep_hrtimer *t = data;
+        struct sleep_hrtimer *t =
+                container_of(timer, struct sleep_hrtimer, timer);
 
         t->expired = 1;
         wake_up_process(t->task);
@@ -677,7 +676,6 @@ static int nanosleep_wakeup(void *data)
 static int __sched do_nanosleep(struct sleep_hrtimer *t, enum hrtimer_mode mode)
 {
         t->timer.function = nanosleep_wakeup;
-        t->timer.data = t;
         t->task = current;
         t->expired = 0;
 
diff --git a/kernel/itimer.c b/kernel/itimer.c
index af2ec6b4392c..204ed7939e75 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -128,17 +128,16 @@ asmlinkage long sys_getitimer(int which, struct itimerval __user *value)
 /*
  * The timer is automagically restarted, when interval != 0
  */
-int it_real_fn(void *data)
+int it_real_fn(struct hrtimer *timer)
 {
-        struct task_struct *tsk = (struct task_struct *) data;
+        struct signal_struct *sig =
+            container_of(timer, struct signal_struct, real_timer);
 
-        send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk);
-
-        if (tsk->signal->it_real_incr.tv64 != 0) {
-                hrtimer_forward(&tsk->signal->real_timer,
-                                tsk->signal->real_timer.base->softirq_time,
-                                tsk->signal->it_real_incr);
+        send_group_sig_info(SIGALRM, SEND_SIG_PRIV, sig->tsk);
 
+        if (sig->it_real_incr.tv64 != 0) {
+                hrtimer_forward(timer, timer->base->softirq_time,
+                                sig->it_real_incr);
                 return HRTIMER_RESTART;
         }
         return HRTIMER_NORESTART;
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 7c5f44787c8c..ac6dc8744429 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -145,7 +145,7 @@ static int common_timer_set(struct k_itimer *, int,
                             struct itimerspec *, struct itimerspec *);
 static int common_timer_del(struct k_itimer *timer);
 
-static int posix_timer_fn(void *data);
+static int posix_timer_fn(struct hrtimer *data);
 
 static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags);
 
@@ -334,14 +334,14 @@ EXPORT_SYMBOL_GPL(posix_timer_event);
 
  * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
  */
-static int posix_timer_fn(void *data)
+static int posix_timer_fn(struct hrtimer *timer)
 {
-        struct k_itimer *timr = data;
-        struct hrtimer *timer = &timr->it.real.timer;
+        struct k_itimer *timr;
         unsigned long flags;
         int si_private = 0;
         int ret = HRTIMER_NORESTART;
 
+        timr = container_of(timer, struct k_itimer, it.real.timer);
         spin_lock_irqsave(&timr->it_lock, flags);
 
         if (timr->it.real.interval.tv64 != 0)
@@ -725,7 +725,6 @@ common_timer_set(struct k_itimer *timr, int flags,
 
         mode = flags & TIMER_ABSTIME ? HRTIMER_ABS : HRTIMER_REL;
         hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
-        timr->it.real.timer.data = timr;
         timr->it.real.timer.function = posix_timer_fn;
 
         timer->expires = timespec_to_ktime(new_setting->it_value);