On Mon, 9 Jul 2007 11:53:02 -0400
[EMAIL PROTECTED] wrote:
> static void print_trace_address(void *data, unsigned long addr)
> {
> + static int i = 0;
> + if (i && ((i % 8) == 0))
> + touch_nmi_watchdog();
> + i++;
> printk_address(addr);
> }
I doubt if the "% 8" thing is really needed? printk_address() is pretty
slow and touch_nmi_watchdog is _reasonably_ fast. It could be made heaps
faster by:
From: Andrew Morton <[EMAIL PROTECTED]>
Avoid dirtying remote cpu's memory if it already has the correct value.
Cc: Andi Kleen <[EMAIL PROTECTED]>
Cc: Konrad Rzeszutek <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
arch/i386/kernel/nmi.c | 8 +++++---
x86_64/kernel/nmi.c | 0
2 files changed, 5 insertions(+), 3 deletions(-)
diff -puN arch/i386/kernel/nmi.c~i386-speedup-touch_nmi_watchdog
arch/i386/kernel/nmi.c
--- a/arch/i386/kernel/nmi.c~i386-speedup-touch_nmi_watchdog
+++ a/arch/i386/kernel/nmi.c
@@ -298,7 +298,7 @@ static unsigned int
last_irq_sums [NR_CPUS],
alert_counter [NR_CPUS];
-void touch_nmi_watchdog (void)
+void touch_nmi_watchdog(void)
{
if (nmi_watchdog > 0) {
unsigned cpu;
@@ -307,8 +307,10 @@ void touch_nmi_watchdog (void)
* Just reset the alert counters, (other CPUs might be
* spinning on locks we hold):
*/
- for_each_present_cpu (cpu)
- alert_counter[cpu] = 0;
+ for_each_present_cpu(cpu) {
+ if (alert_counter[cpu])
+ alert_counter[cpu] = 0;
+ }
}
/*
So I'd be inclined to simplify your patch to a bare
From: Konrad Rzeszutek <[EMAIL PROTECTED]>
On large memory configuration with not so fast CPUs the NMI watchdog is
triggered when memory addresses are being gathered and printed. The code
paths for Alt-SysRq-t are sprinkled with touch_nmi_watchdog in various
places but not in this routine (or in the loop that utilizes this
function). The patch has been tested for regression on large CPU+memory
configuration (128 logical CPUs + 224 GB) and 1,2,4,16-CPU sockets with
various memory sizes (1,2,4,6,20).
Cc: Andi Kleen <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
arch/x86_64/kernel/traps.c | 1 +
1 files changed, 1 insertion(+)
diff -puN
arch/x86_64/kernel/traps.c~inhibit-nmi-watchdog-when-alt-sysrq-t-operation-is-underway
arch/x86_64/kernel/traps.c
---
a/arch/x86_64/kernel/traps.c~inhibit-nmi-watchdog-when-alt-sysrq-t-operation-is-underway
+++ a/arch/x86_64/kernel/traps.c
@@ -397,6 +397,7 @@ static int print_trace_stack(void *data,
static void print_trace_address(void *data, unsigned long addr)
{
+ touch_nmi_watchdog();
printk_address(addr);
}
_
OK?
-
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