[PATCH] Allow for profile_buf size = kernel text size

Patch from Ravikiran G Thirumalai <kiran@in.ibm.com>

Allows the kernel profiler to use a shift value of zero for
high-resolution profiling.

So instead of overloading a shift of zero to mean "not profiling", use
a separate flag for that.

This means that anyone who is currently using "profile=0" to disable
profiling has accidentally turned profiling on, so I added a printk.

fs/proc/proc_misc.c

@@ -602,7 +602,7 @@ void __init proc_misc_init(void)
 		proc_root_kcore->size =
 				(size_t)high_memory - PAGE_OFFSET + PAGE_SIZE;
 	}
-	if (prof_shift) {
+	if (prof_on) {
 		entry = create_proc_entry("profile", S_IWUSR | S_IRUGO, NULL);
 		if (entry) {
 			entry->proc_fops = &proc_profile_operations;

include/linux/profile.h

@@ -17,6 +17,7 @@ void __init profile_init(void);
 extern unsigned int * prof_buffer;
 extern unsigned long prof_len;
 extern unsigned long prof_shift;
+extern int prof_on;
 
 
 enum profile_type {

kernel/profile.c

@@ -14,12 +14,16 @@ extern char _stext, _etext;
 unsigned int * prof_buffer;
 unsigned long prof_len;
 unsigned long prof_shift;
+int prof_on;
 
 int __init profile_setup(char * str)
 {
 	int par;
-	if (get_option(&str,&par))
+	if (get_option(&str,&par)) {
 		prof_shift = par;
+		prof_on = 1;
+		printk(KERN_INFO "kernel profiling enabled\n");
+	}
 	return 1;
 }
 
@@ -28,7 +32,7 @@ void __init profile_init(void)
 {
 	unsigned int size;
  
-	if (!prof_shift) 
+	if (!prof_on) 
 		return;
  
 	/* only text is profiled */