i386: fix a hang on stuck nmi watchdog

In the case when an nmi gets stucks the endflag stays equal to zero. This causes the busy looping on other cpus to continue, even tho the nmi test is done.

On my machine with out the change below the system would hang right after check_nmi_watchdog(). The change below just sets endflag prior to checking if the test was successful or not.

Signed-off-by Daniel Walker <[email protected]>

---
 arch/i386/kernel/nmi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6.22/arch/i386/kernel/nmi.c
===================================================================

arch/i386/kernel/nmi.c +1 -1

@@ -115,12 +115,12 @@ static int __init check_nmi_watchdog(voi
 			atomic_dec(&nmi_active);
 		}
 	}
+	endflag = 1;
 	if (!atomic_read(&nmi_active)) {
 		kfree(prev_nmi_count);
 		atomic_set(&nmi_active, -1);
 		return -1;
 	}
-	endflag = 1;
 	printk("OK.\n");
 
 	/* now that we know it works we can reduce NMI frequency to

Signature · 1 line

-- 

Daniel,

Thanks for your help tracking down this bug. Maybe we can close the bugzilla report now.

In the case when an nmi gets stucks the endflag stays equal to zero. This causes the busy looping on other cpus to continue, even tho the nmi test is done.

On my machine with out the change below the system would hang right after check_nmi_watchdog(). The change below just sets endflag prior to checking if the test was successful or not.

Signed-off-by Daniel Walker <[email protected]>

Quoted 4 lines · On Saturday 01 September 2007 22:54:17 Daniel Walker wrote:

In the case when an nmi gets stucks the endflag stays equal to zero. This causes the busy looping on other cpus to continue, even tho the nmi test is done.

Quoted 5 lines

On my machine with out the change below the system would hang right after check_nmi_watchdog(). The change below just sets endflag prior to checking if the test was successful or not.

Signed-off-by Daniel Walker <[email protected]>

Added thanks. I guess it's .23 material.