[PATCH] x86-64: Inhibit machine from asserting an NMI when doing Alt-SysRq-M operation.

This patch touches the NMI watchdog every MAX_ORDER_NR_PAGES
to inhibit the machine from triggering an NMI while the CPUs
are locked. This situation is happening on boxes with more
than 64CPUs and 128GB of RAM when Alt-SysRq-m is performed.

It has been succesfully tested for regression on uni, 2, 4, 8
32, and 64 CPU boxes with various memory configuration.

Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
Konrad Rzeszutek 2007-05-02 19:27:11 +02:00 committed by Andi Kleen
parent c8118c6c07
commit ae32b1297a

View file

@ -27,6 +27,7 @@
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/memory_hotplug.h>
#include <linux/nmi.h>
#include <asm/processor.h>
#include <asm/system.h>
@ -73,6 +74,11 @@ void show_mem(void)
for_each_online_pgdat(pgdat) {
for (i = 0; i < pgdat->node_spanned_pages; ++i) {
/* this loop can take a while with 256 GB and 4k pages
so update the NMI watchdog */
if (unlikely(i % MAX_ORDER_NR_PAGES == 0)) {
touch_nmi_watchdog();
}
page = pfn_to_page(pgdat->node_start_pfn + i);
total++;
if (PageReserved(page))