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Commit 52baf119 authored by Steven Rostedt's avatar Steven Rostedt
Browse files

ftrace: convert ftrace_lock from a spinlock to mutex 



Impact: clean up

The older versions of ftrace required doing the ftrace list
search under atomic context. Now all the calls are in non-atomic
context. There is no reason to keep the ftrace_lock as a spinlock.

This patch converts it to a mutex.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
parent f6180773

kernel/trace/ftrace.c

+19 −32
Original line number Diff line number Diff line
@@ -61,7 +61,7 @@ int function_trace_stop; 
 */

static int ftrace_disabled __read_mostly;



static DEFINE_SPINLOCK(ftrace_lock);

static DEFINE_MUTEX(ftrace_lock);

static DEFINE_MUTEX(ftrace_sysctl_lock);

static DEFINE_MUTEX(ftrace_start_lock);
@@ -134,8 +134,7 @@ static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) 


static int __register_ftrace_function(struct ftrace_ops *ops)

{

	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);

	mutex_lock(&ftrace_lock);



	ops->next = ftrace_list;

	/*
@@ -172,7 +171,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) 
#endif

	}



	spin_unlock(&ftrace_lock);

	mutex_unlock(&ftrace_lock);



	return 0;

}
@@ -182,8 +181,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) 
	struct ftrace_ops **p;

	int ret = 0;



	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);

	mutex_lock(&ftrace_lock);



	/*

	 * If we are removing the last function, then simply point
@@ -224,7 +222,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) 
	}



 out:

	spin_unlock(&ftrace_lock);

	mutex_unlock(&ftrace_lock);



	return ret;

}
@@ -233,8 +231,7 @@ static void ftrace_update_pid_func(void) 
{

	ftrace_func_t func;



	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);

	mutex_lock(&ftrace_lock);



	if (ftrace_trace_function == ftrace_stub)

		goto out;
@@ -256,7 +253,7 @@ static void ftrace_update_pid_func(void) 
#endif



 out:

	spin_unlock(&ftrace_lock);

	mutex_unlock(&ftrace_lock);

}



#ifdef CONFIG_DYNAMIC_FTRACE
@@ -358,15 +355,12 @@ void ftrace_release(void *start, unsigned long size) 
	if (ftrace_disabled || !start)

		return;



	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);



	mutex_lock(&ftrace_lock);

	do_for_each_ftrace_rec(pg, rec) {

		if ((rec->ip >= s) && (rec->ip < e))

			ftrace_free_rec(rec);

	} while_for_each_ftrace_rec();



	spin_unlock(&ftrace_lock);

	mutex_unlock(&ftrace_lock);

}



static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
@@ -803,8 +797,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos) 
	if (iter->flags & FTRACE_ITER_PRINTALL)

		return NULL;



	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);

	mutex_lock(&ftrace_lock);

 retry:

	if (iter->idx >= iter->pg->index) {

		if (iter->pg->next) {
@@ -833,7 +826,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos) 
			goto retry;

		}

	}

	spin_unlock(&ftrace_lock);

	mutex_unlock(&ftrace_lock);



	return rec;

}
@@ -962,8 +955,7 @@ static void ftrace_filter_reset(int enable) 
	struct dyn_ftrace *rec;

	unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;



	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);

	mutex_lock(&ftrace_lock);

	if (enable)

		ftrace_filtered = 0;

	do_for_each_ftrace_rec(pg, rec) {
@@ -971,8 +963,7 @@ static void ftrace_filter_reset(int enable) 
			continue;

		rec->flags &= ~type;

	} while_for_each_ftrace_rec();



	spin_unlock(&ftrace_lock);

	mutex_unlock(&ftrace_lock);

}



static int
@@ -1151,8 +1142,7 @@ static void ftrace_match_records(char *buff, int len, int enable) 


	search_len = strlen(search);



	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);

	mutex_lock(&ftrace_lock);

	do_for_each_ftrace_rec(pg, rec) {



		if (rec->flags & FTRACE_FL_FAILED)
@@ -1171,7 +1161,7 @@ static void ftrace_match_records(char *buff, int len, int enable) 
		if (enable && (rec->flags & FTRACE_FL_FILTER))

			ftrace_filtered = 1;

	} while_for_each_ftrace_rec();

	spin_unlock(&ftrace_lock);

	mutex_unlock(&ftrace_lock);

}



static int
@@ -1218,8 +1208,7 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable) 
		search_len = strlen(search);

	}



	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);

	mutex_lock(&ftrace_lock);

	do_for_each_ftrace_rec(pg, rec) {



		if (rec->flags & FTRACE_FL_FAILED)
@@ -1236,7 +1225,7 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable) 
			ftrace_filtered = 1;



	} while_for_each_ftrace_rec();

	spin_unlock(&ftrace_lock);

	mutex_unlock(&ftrace_lock);

}



/*
@@ -1676,9 +1665,7 @@ ftrace_set_func(unsigned long *array, int idx, char *buffer) 
	if (ftrace_disabled)

		return -ENODEV;



	/* should not be called from interrupt context */

	spin_lock(&ftrace_lock);



	mutex_lock(&ftrace_lock);

	do_for_each_ftrace_rec(pg, rec) {



		if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
@@ -1699,7 +1686,7 @@ ftrace_set_func(unsigned long *array, int idx, char *buffer) 
		}

	} while_for_each_ftrace_rec();

 out:

	spin_unlock(&ftrace_lock);

	mutex_unlock(&ftrace_lock);



	return found ? 0 : -EINVAL;

}