oprofile: convert oprofile from timer_hook to hrtimer
Oprofile is currently broken on systems running with NOHZ enabled.
A maximum of 1 tick is accounted via the timer_hook if a cpu sleeps
for a longer period of time. This does bad things to the percentages
in the profiler output. To solve this problem convert oprofile to
use a restarting hrtimer instead of the timer_hook.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
index dc8a042..b336cd9 100644
--- a/drivers/oprofile/oprof.c
+++ b/drivers/oprofile/oprof.c
@@ -253,22 +253,26 @@
int err;
err = oprofile_arch_init(&oprofile_ops);
-
if (err < 0 || timer) {
printk(KERN_INFO "oprofile: using timer interrupt.\n");
- oprofile_timer_init(&oprofile_ops);
+ err = oprofile_timer_init(&oprofile_ops);
+ if (err)
+ goto out_arch;
}
-
err = oprofilefs_register();
if (err)
- oprofile_arch_exit();
+ goto out_arch;
+ return 0;
+out_arch:
+ oprofile_arch_exit();
return err;
}
static void __exit oprofile_exit(void)
{
+ oprofile_timer_exit();
oprofilefs_unregister();
oprofile_arch_exit();
}