Re: [PATCH] Export touch_nmi_watchdog

[Andi Kleen <ak@colin2.muc.de>]

On Tue, Aug 05, 2003 at 03:14:00PM -0700, Linus Torvalds wrote:
> 	#ifdef CONFIG_WATCHDOG
> 	#warning This driver does bad things and will not work
> 	#endif

Well the problem is that many of my multiple CPU testboxes have a fusion
controller (it's the standard on board chip on the AMD Quartet and Newisys
systems). 

At least for my testing it would be quite inconvenient to not
have the watchdog. I also don't see anybody comming around and fixing
the SCSI error handler of that driver (scsi error handlers seem
to be always very bad code, undoubtedly because it's a ugly problem)

(fortunately errors happen only infrequently, usually when I break
something else...) 

But still I would prefer the NMI watchdog not triggering then.

> So let the user know. Don't just silently say "let's kick the watchdog".

How about this approach: 

Define a new function driver_touch_watchdog() for export and it printks
something the first time it is used.

--- linux-2.6.0test2-amd64/arch/i386/kernel/nmi.c-o	2003-07-11 03:09:18.000000000 +0200
+++ linux-2.6.0test2-amd64/arch/i386/kernel/nmi.c	2003-08-06 02:03:41.000000000 +0200
@@ -25,6 +25,7 @@
 #include <linux/module.h>
 #include <linux/nmi.h>
 #include <linux/sysdev.h>
+#include <linux/kallsyms.h>
 
 #include <asm/smp.h>
 #include <asm/mtrr.h>
@@ -455,3 +456,18 @@
 EXPORT_SYMBOL(enable_lapic_nmi_watchdog);
 EXPORT_SYMBOL(disable_timer_nmi_watchdog);
 EXPORT_SYMBOL(enable_timer_nmi_watchdog);
+
+/* Deprecated function to silence the NMI watchdog for long waits.
+   Better fix the driver instead of using this. */
+void driver_touch_watchdog(void)
+{ 
+	static int used; 
+	if (!used) { 
+		print_symbol(KERN_ERR "Function %s uses driver_touch_watchdog.\n",
+			     __builtin_return_address(0));
+	} 
+	used = 1;
+	touch_nmi_watchdog();
+}  
+
+EXPORT_SYMBOL(driver_touch_watchdog);

-Andi