[PATCH 2/3] lockup_detector: convert cpu notifier to return encapsulate errno value

Don Zickus
2010-09-01T03:00:24Z

From: Akinobu Mita <akinobu.mita@gmail.com>

By the commit e6bde73b07edeb703d4c89c1daabc09c303de11f
("cpu-hotplug: return better errno on cpu hotplug failure"),
the cpu notifier can return encapsulate errno value.

This converts the cpu notifier to return encapsulate errno value
for lockup_detector.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Don Zickus <dzickus@redhat.com>
---
kernel/watchdog.c | 21 +++++++++++----------
1 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 7f9c3c5..db70647 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -378,7 +378,7 @@ static int watchdog_nmi_enable(int cpu)
}

printk(KERN_ERR "NMI watchdog failed to create perf event on cpu%i: %p\n", cpu, event);
- return -1;
+ return PTR_ERR(event);

/* success path */
out_save:
@@ -422,17 +422,19 @@ static int watchdog_prepare_cpu(int cpu)
static int watchdog_enable(int cpu)
{
struct task_struct *p = per_cpu(softlockup_watchdog, cpu);
+ int err;

/* enable the perf event */
- if (watchdog_nmi_enable(cpu) != 0)
- return -1;
+ err = watchdog_nmi_enable(cpu);
+ if (err)
+ return err;

/* create the watchdog thread */
if (!p) {
p = kthread_create(watchdog, (void *)(unsigned long)cpu, "watchdog/%d", cpu);
if (IS_ERR(p)) {
printk(KERN_ERR "softlockup watchdog for %i failed\n", cpu);
- return -1;
+ return PTR_ERR(p);
}
kthread_bind(p, cpu);
per_cpu(watchdog_touch_ts, cpu) = 0;
@@ -526,17 +528,16 @@ static int __cpuinit
cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
int hotcpu = (unsigned long)hcpu;
+ int err = 0;

switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- if (watchdog_prepare_cpu(hotcpu))
- return NOTIFY_BAD;
+ err = watchdog_prepare_cpu(hotcpu);
break;
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
- if (watchdog_enable(hotcpu))
- return NOTIFY_BAD;
+ err = watchdog_enable(hotcpu);
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
@@ -549,7 +550,7 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
break;
#endif /* CONFIG_HOTPLUG_CPU */
}
- return NOTIFY_OK;
+ return notifier_from_errno(err);
}

static struct notifier_block __cpuinitdata cpu_nfb = {
@@ -565,7 +566,7 @@ static int __init spawn_watchdog_task(void)
return 0;

err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu);
- WARN_ON(err == NOTIFY_BAD);
+ WARN_ON(notifier_to_errno(err));

cpu_callback(&cpu_nfb, CPU_ONLINE, cpu);
register_cpu_notifier(&cpu_nfb);
--
1.7.2.2