提交 96ca4028 编写于 作者: D Don Zickus 提交者: Ingo Molnar

nmi_watchdog: Properly configure for software events

Paul Mackerras brought up a good point that when fallbacking to
software events, I may have been lucky in my configuration.

Modified the code to explicit provide a new configuration for
software events.
Suggested-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Cc: gorcunov@gmail.com
Cc: aris@redhat.com
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1266357745-26671-1-git-send-email-dzickus@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
上级 6081b6cd
......@@ -61,7 +61,7 @@ static int __init setup_nmi_watchdog(char *str)
}
__setup("nmi_watchdog=", setup_nmi_watchdog);
struct perf_event_attr wd_attr = {
struct perf_event_attr wd_hw_attr = {
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
.size = sizeof(struct perf_event_attr),
......@@ -69,6 +69,14 @@ struct perf_event_attr wd_attr = {
.disabled = 1,
};
struct perf_event_attr wd_sw_attr = {
.type = PERF_TYPE_SOFTWARE,
.config = PERF_COUNT_SW_CPU_CLOCK,
.size = sizeof(struct perf_event_attr),
.pinned = 1,
.disabled = 1,
};
void wd_overflow(struct perf_event *event, int nmi,
struct perf_sample_data *data,
struct pt_regs *regs)
......@@ -105,6 +113,7 @@ void wd_overflow(struct perf_event *event, int nmi,
static int enable_nmi_watchdog(int cpu)
{
struct perf_event *event;
struct perf_event_attr *wd_attr;
event = per_cpu(nmi_watchdog_ev, cpu);
if (event && event->state > PERF_EVENT_STATE_OFF)
......@@ -112,11 +121,15 @@ static int enable_nmi_watchdog(int cpu)
if (event == NULL) {
/* Try to register using hardware perf events first */
wd_attr.sample_period = hw_nmi_get_sample_period();
event = perf_event_create_kernel_counter(&wd_attr, cpu, -1, wd_overflow);
wd_attr = &wd_hw_attr;
wd_attr->sample_period = hw_nmi_get_sample_period();
event = perf_event_create_kernel_counter(wd_attr, cpu, -1, wd_overflow);
if (IS_ERR(event)) {
wd_attr.type = PERF_TYPE_SOFTWARE;
event = perf_event_create_kernel_counter(&wd_attr, cpu, -1, wd_overflow);
/* hardware doesn't exist or not supported, fallback to software events */
printk("nmi_watchdog: hardware not available, trying software events\n");
wd_attr = &wd_sw_attr;
wd_attr->sample_period = NSEC_PER_SEC;
event = perf_event_create_kernel_counter(wd_attr, cpu, -1, wd_overflow);
if (IS_ERR(event)) {
printk(KERN_ERR "nmi watchdog failed to create perf event on %i: %p\n", cpu, event);
return -1;
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册