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authorDavid S. Miller <davem@davemloft.net>2009-02-02 21:57:48 -0800
committerDavid S. Miller <davem@davemloft.net>2009-02-02 21:57:48 -0800
commit802c64b310e5b9dfda6cb50b850b962ed96a9e81 (patch)
tree5dbb6172dac4647c7489cca35d2d79c8cb3f988c /arch/sparc
parente5553a6d04421eec326a629571d696e8e745a0e4 (diff)
sparc64: On non-Niagara, need to touch NMI watchdog in NOHZ mode.
When we're idling in NOHZ mode, timer interrupts are not running. Evidence of processing timer interrupts is what the NMI watchdog uses to determine if the CPU is stuck. On Niagara, we'll yield the cpu. This will make the cpu, at worst, hang out in the hypervisor until an interrupt arrives. This will prevent the NMI watchdog timer from firing. However on non-Niagara we just loop executing instructions which will cause the NMI watchdog to keep firing. It won't see timer interrupts happening so it will think the cpu is stuck. Fix this by touching the NMI watchdog in the cpu idle loop on non-Niagara machines. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc')
-rw-r--r--arch/sparc/kernel/process_64.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index cc8b5604442..a73954b87f0 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -29,6 +29,7 @@
#include <linux/cpu.h>
#include <linux/elfcore.h>
#include <linux/sysrq.h>
+#include <linux/nmi.h>
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -52,8 +53,10 @@
static void sparc64_yield(int cpu)
{
- if (tlb_type != hypervisor)
+ if (tlb_type != hypervisor) {
+ touch_nmi_watchdog();
return;
+ }
clear_thread_flag(TIF_POLLING_NRFLAG);
smp_mb__after_clear_bit();