After the previous patches, the notifier interface now has it's own
locking. Therefore the existing locking done by the profile interface
is superfluous.
This has been tested by repeated loading/unloading the oprofile driver
while profiling was on.
# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or
higher.
# This patch includes the following deltas:
# ChangeSet 1.985 -> 1.986
# arch/i386/kernel/profile.c 1.2 -> 1.3
# kernel/profile.c 1.4 -> 1.5
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/12/17 [email protected] 1.986
# Locking now handled by notifier
# --------------------------------------------
#
diff -Nru a/arch/i386/kernel/profile.c b/arch/i386/kernel/profile.c
--- a/arch/i386/kernel/profile.c Tue Dec 17 11:25:47 2002
+++ b/arch/i386/kernel/profile.c Tue Dec 17 11:25:47 2002
@@ -6,40 +6,25 @@
*/
#include <linux/profile.h>
-#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <linux/irq.h>
#include <asm/hw_irq.h>
static LIST_HEAD(profile_listeners);
-static rwlock_t profile_lock = RW_LOCK_UNLOCKED;
int register_profile_notifier(struct notifier_block * nb)
{
- int err;
- write_lock_irq(&profile_lock);
- err = notifier_chain_register(&profile_listeners, nb);
- write_unlock_irq(&profile_lock);
- return err;
+ return notifier_chain_register(&profile_listeners, nb);
}
int unregister_profile_notifier(struct notifier_block * nb)
{
- int err;
- write_lock_irq(&profile_lock);
- err = notifier_chain_unregister(&profile_listeners, nb);
- write_unlock_irq(&profile_lock);
- return err;
+ return notifier_chain_unregister(&profile_listeners, nb);
}
void x86_profile_hook(struct pt_regs * regs)
{
- /* we would not even need this lock if
- * we had a global cli() on register/unregister
- */
- read_lock(&profile_lock);
notifier_call_chain(&profile_listeners, 0, regs);
- read_unlock(&profile_lock);
}
diff -Nru a/kernel/profile.c b/kernel/profile.c
--- a/kernel/profile.c Tue Dec 17 11:25:47 2002
+++ b/kernel/profile.c Tue Dec 17 11:25:47 2002
@@ -47,38 +47,29 @@
#ifdef CONFIG_PROFILING
-static DECLARE_RWSEM(profile_rwsem);
static LIST_HEAD(exit_task_notifier);
static LIST_HEAD(exit_mmap_notifier);
static LIST_HEAD(exec_unmap_notifier);
void profile_exit_task(struct task_struct * task)
{
- down_read(&profile_rwsem);
notifier_call_chain(&exit_task_notifier, 0, task);
- up_read(&profile_rwsem);
}
void profile_exit_mmap(struct mm_struct * mm)
{
- down_read(&profile_rwsem);
notifier_call_chain(&exit_mmap_notifier, 0, mm);
- up_read(&profile_rwsem);
}
void profile_exec_unmap(struct mm_struct * mm)
{
- down_read(&profile_rwsem);
notifier_call_chain(&exec_unmap_notifier, 0, mm);
- up_read(&profile_rwsem);
}
int profile_event_register(enum profile_type type, struct
notifier_block * n)
{
int err = -EINVAL;
- down_write(&profile_rwsem);
-
switch (type) {
case EXIT_TASK:
err = notifier_chain_register(&exit_task_notifier, n);
@@ -91,8 +82,6 @@
break;
}
- up_write(&profile_rwsem);
-
return err;
}
@@ -101,8 +90,6 @@
{
int err = -EINVAL;
- down_write(&profile_rwsem);
-
switch (type) {
case EXIT_TASK:
err = notifier_chain_unregister(&exit_task_notifier, n);
@@ -115,7 +102,6 @@
break;
}
- up_write(&profile_rwsem);
return err;
}