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[PATCH] i386/x86-64: Fix NMI watchdog suspend/resume

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Making NMI suspend/resume work with SMP. We use CPU hotplug to offline
APs in SMP suspend/resume. Only BSP executes sysdev's .suspend/.resume
method. APs should follow CPU hotplug code path.

And:

+From: Don Zickus <dzickus@redhat.com>

Makes the start/stop paths of nmi watchdog more robust to handle the
suspend/resume cases more gracefully.

AK: I merged the two patches together

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
This commit is contained in:
Shaohua Li
2006-09-26 10:52:27 +02:00
committed by Andi Kleen
parent c41c5cd3b2
commit 4038f901cf
6 changed files with 58 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
arch/i386/kernel/nmi.c
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@@ -63,7 +63,6 @@ struct nmi_watchdog_ctlblk {
static DEFINE_PER_CPU(struct nmi_watchdog_ctlblk, nmi_watchdog_ctlblk);
/* local prototypes */
static void stop_apic_nmi_watchdog(void *unused);
static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu);
extern void show_registers(struct pt_regs *regs);
@@ -341,15 +340,20 @@ static int nmi_pm_active; /* nmi_active before suspend */
static int lapic_nmi_suspend(struct sys_device *dev, pm_message_t state)
{
/* only CPU0 goes here, other CPUs should be offline */
nmi_pm_active = atomic_read(&nmi_active);
disable_lapic_nmi_watchdog();
stop_apic_nmi_watchdog(NULL);
BUG_ON(atomic_read(&nmi_active) != 0);
return 0;
}
static int lapic_nmi_resume(struct sys_device *dev)
{
if (nmi_pm_active > 0)
enable_lapic_nmi_watchdog();
/* only CPU0 goes here, other CPUs should be offline */
if (nmi_pm_active > 0) {
setup_apic_nmi_watchdog(NULL);
touch_nmi_watchdog();
}
return 0;
}
@@ -626,11 +630,21 @@ static void stop_p4_watchdog(void)
void setup_apic_nmi_watchdog (void *unused)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
/* only support LOCAL and IO APICs for now */
if ((nmi_watchdog != NMI_LOCAL_APIC) &&
(nmi_watchdog != NMI_IO_APIC))
return;
if (wd->enabled == 1)
return;
/* cheap hack to support suspend/resume */
/* if cpu0 is not active neither should the other cpus */
if ((smp_processor_id() != 0) && (atomic_read(&nmi_active) <= 0))
return;
if (nmi_watchdog == NMI_LOCAL_APIC) {
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
@@ -663,17 +677,22 @@ void setup_apic_nmi_watchdog (void *unused)
return;
}
}
__get_cpu_var(nmi_watchdog_ctlblk.enabled) = 1;
wd->enabled = 1;
atomic_inc(&nmi_active);
}
static void stop_apic_nmi_watchdog(void *unused)
void stop_apic_nmi_watchdog(void *unused)
{
struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
/* only support LOCAL and IO APICs for now */
if ((nmi_watchdog != NMI_LOCAL_APIC) &&
(nmi_watchdog != NMI_IO_APIC))
return;
if (wd->enabled == 0)
return;
if (nmi_watchdog == NMI_LOCAL_APIC) {
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
@@ -697,7 +716,7 @@ static void stop_apic_nmi_watchdog(void *unused)
return;
}
}
__get_cpu_var(nmi_watchdog_ctlblk.enabled) = 0;
wd->enabled = 0;
atomic_dec(&nmi_active);
}