Re: [mm patch] oprofile: backtrace operation does not initialized

[Greg Banks]

On Wed, Dec 08, 2004 at 04:00:55PM +0000, John Levon wrote:
> On Wed, Dec 08, 2004 at 06:30:51PM +0900, Akinobu Mita wrote:
> 
> > When I forced the oprofile to use timer interrupt with specifying
> > "timer=1" module parameter. "oprofile_operations->backtrace" did
> > not initialized on i386.
> > 
> > Please apply this patch, or make oprofile initialize the backtrace
> > operation in case of using timer interrupt in your preferable way.
> 
> I don't like this patch. The arches should just set the backtrace
> always, then try to init the hardware. oprofile_init() should then force
> the timer ops as needed.
> 
> Greg?

Agreed, that's a cleaner approach.  The attached patch (untested)
implements that.  Akinobu-san, can you please test the patch?

Greg.
-- 
Greg Banks, R&D Software Engineer, SGI Australian Software Group.
I don't speak for SGI.
Allow stack tracing to work when sampling on timer is forced
using the timer=1 boot option.  Reported by Akinobu Mita.

Signed-off-by: Greg Banks <gnb@xxxxxxxxxxxxxxxxx>
---
 oprof.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)


Index: linux/drivers/oprofile/oprof.c
===================================================================
--- linux.orig/drivers/oprofile/oprof.c	2004-12-04 19:43:37.%N +1100
+++ linux/drivers/oprofile/oprof.c	2004-12-09 09:25:02.%N +1100
@@ -155,13 +155,11 @@ static int __init oprofile_init(void)
 {
 	int err = 0;
 
-	/* this is our fallback case */
-	oprofile_timer_init(&oprofile_ops);
+	oprofile_arch_init(&oprofile_ops);
 
 	if (timer) {
 		printk(KERN_INFO "oprofile: using timer interrupt.\n");
-	} else {
-		oprofile_arch_init(&oprofile_ops);
+		oprofile_timer_init(&oprofile_ops);
 	}
 
 	err = oprofilefs_register();