profiling: Remove unused timer hook

The last remaining user was oprofile and its use has been
removed a while ago in commit bc078e4eab65f11bba
("oprofile: convert oprofile from timer_hook to hrtimer").

There doesn't seem to be any upstream user of this hook
for about two years now. And I'm not even aware of any out of
tree user.

Let's remove it.

Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Alessio Igor Bogani <[email protected]>
Cc: Avi Kivity <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Geoff Levand <[email protected]>
Cc: Gilad Ben Yossef <[email protected]>
Cc: Hakan Akkan <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Paul Gortmaker <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

2 files changed, 0 insertions, 37 deletions

diff --git a/include/linux/profile.h b/include/linux/profile.h
index a0fc32279fc0..21123902366d 100644
--- a/include/linux/profile.h
+++ b/include/linux/profile.h
@@ -82,9 +82,6 @@ int task_handoff_unregister(struct notifier_block * n);
 int profile_event_register(enum profile_type, struct notifier_block * n);
 int profile_event_unregister(enum profile_type, struct notifier_block * n);
 
-int register_timer_hook(int (*hook)(struct pt_regs *));
-void unregister_timer_hook(int (*hook)(struct pt_regs *));
-
 struct pt_regs;
 
 #else
@@ -135,16 +132,6 @@ static inline int profile_event_unregister(enum profile_type t, struct notifier_
 #define profile_handoff_task(a) (0)
 #define profile_munmap(a) do { } while (0)
 
-static inline int register_timer_hook(int (*hook)(struct pt_regs *))
-{
-	return -ENOSYS;
-}
-
-static inline void unregister_timer_hook(int (*hook)(struct pt_regs *))
-{
-	return;
-}
-
 #endif /* CONFIG_PROFILING */
 
 #endif /* _LINUX_PROFILE_H */
diff --git a/kernel/profile.c b/kernel/profile.c
index 1f391819c42f..dc3384ee874e 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -37,9 +37,6 @@ struct profile_hit {
 #define NR_PROFILE_HIT		(PAGE_SIZE/sizeof(struct profile_hit))
 #define NR_PROFILE_GRP		(NR_PROFILE_HIT/PROFILE_GRPSZ)
 
-/* Oprofile timer tick hook */
-static int (*timer_hook)(struct pt_regs *) __read_mostly;
-
 static atomic_t *prof_buffer;
 static unsigned long prof_len, prof_shift;
 
@@ -208,25 +205,6 @@ int profile_event_unregister(enum profile_type type, struct notifier_block *n)
 }
 EXPORT_SYMBOL_GPL(profile_event_unregister);
 
-int register_timer_hook(int (*hook)(struct pt_regs *))
-{
-	if (timer_hook)
-		return -EBUSY;
-	timer_hook = hook;
-	return 0;
-}
-EXPORT_SYMBOL_GPL(register_timer_hook);
-
-void unregister_timer_hook(int (*hook)(struct pt_regs *))
-{
-	WARN_ON(hook != timer_hook);
-	timer_hook = NULL;
-	/* make sure all CPUs see the NULL hook */
-	synchronize_sched();  /* Allow ongoing interrupts to complete. */
-}
-EXPORT_SYMBOL_GPL(unregister_timer_hook);
-
-
 #ifdef CONFIG_SMP
 /*
  * Each cpu has a pair of open-addressed hashtables for pending
@@ -436,8 +414,6 @@ void profile_tick(int type)
 {
 	struct pt_regs *regs = get_irq_regs();
 
-	if (type == CPU_PROFILING && timer_hook)
-		timer_hook(regs);
 	if (!user_mode(regs) && prof_cpu_mask != NULL &&
 	    cpumask_test_cpu(smp_processor_id(), prof_cpu_mask))
 		profile_hit(type, (void *)profile_pc(regs));