[PATCH] oprofile - timer hook

This implements a simple hook into the profiling timer for x86 so that
non-perfctr machines can still use oprofile.  This has proven useful for
laptops and the like.

It also reduces header dependencies a bit by centralising readprofile
code

1 files changed, 30 insertions, 0 deletions

diff --git a/kernel/profile.c b/kernel/profile.c
index 7ebffe971ca8..756f142b1f35 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -9,6 +9,36 @@
 #include <linux/notifier.h>
 #include <linux/mm.h>
 
+extern char _stext, _etext;
+
+unsigned int * prof_buffer;
+unsigned long prof_len;
+unsigned long prof_shift;
+
+int __init profile_setup(char * str)
+{
+	int par;
+	if (get_option(&str,&par))
+		prof_shift = par;
+	return 1;
+}
+
+
+void __init profile_init(void)
+{
+	unsigned int size;
+ 
+	if (!prof_shift) 
+		return;
+ 
+	/* only text is profiled */
+	prof_len = (unsigned long) &_etext - (unsigned long) &_stext;
+	prof_len >>= prof_shift;
+		
+	size = prof_len * sizeof(unsigned int) + PAGE_SIZE - 1;
+	prof_buffer = (unsigned int *) alloc_bootmem(size);
+}
+
 /* Profile event notifications */
  
 #ifdef CONFIG_PROFILING