[PATCH V2] tmp patch to fix hotplug issue in CMCI storm

From: Chen Gong
Date: Mon Jun 18 2012 - 02:44:30 EST


This patch is based on previous 5 patches and tuned based on
Thomas' suggestion.

Signed-off-by: Chen Gong <gong.chen@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/mcheck/mce-internal.h | 2 ++
arch/x86/kernel/cpu/mcheck/mce.c | 1 +
arch/x86/kernel/cpu/mcheck/mce_intel.c | 22 ++++++++++++++++++++++
3 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h
index 2cd73ce..6a05c1d 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h
@@ -31,9 +31,11 @@ extern struct mce_bank *mce_banks;
#ifdef CONFIG_X86_MCE_INTEL
unsigned long mce_intel_adjust_timer(unsigned long interval);
void mce_intel_cmci_poll(void);
+void mce_intel_hcpu_update(unsigned long cpu);
#else
# define mce_intel_adjust_timer mce_adjust_timer_default
static inline void mce_intel_cmci_poll(void) { }
+static inline void mce_intel_hcpu_update(unsigned long cpu) { }
#endif

void mce_timer_kick(unsigned long interval);
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index e3f8b94..5e22d99 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -2306,6 +2306,7 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
if (threshold_cpu_callback)
threshold_cpu_callback(action, cpu);
mce_device_remove(cpu);
+ mce_intel_hcpu_update(cpu);
break;
case CPU_DOWN_PREPARE:
smp_call_function_single(cpu, mce_disable_cpu, &action, 1);
diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c
index 92d8b5c..0493525 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_intel.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c
@@ -40,6 +40,7 @@ static DEFINE_RAW_SPINLOCK(cmci_discover_lock);
static DEFINE_PER_CPU(unsigned long, cmci_time_stamp);
static DEFINE_PER_CPU(unsigned int, cmci_storm_cnt);
static DEFINE_PER_CPU(unsigned int, cmci_storm_state);
+static DEFINE_PER_CPU(unsigned long, cmci_storm_hcpu_status);

enum {
CMCI_STORM_NONE,
@@ -47,6 +48,11 @@ enum {
CMCI_STORM_SUBSIDED,
};

+enum {
+ CMCI_STORM_HCPU_NONE,
+ CMCI_STORM_HCPU_ACTIVE,
+};
+
static atomic_t cmci_storm_on_cpus;

static int cmci_supported(int *banks)
@@ -77,6 +83,17 @@ void mce_intel_cmci_poll(void)
machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
}

+void mce_intel_hcpu_update(unsigned long cpu)
+{
+ unsigned long *status = &per_cpu(cmci_storm_hcpu_status, cpu);
+
+ if (*status == CMCI_STORM_HCPU_ACTIVE) {
+ per_cpu(cmci_storm_state, cpu) = CMCI_STORM_NONE;
+ *status = CMCI_STORM_HCPU_NONE;
+ atomic_dec(&cmci_storm_on_cpus);
+ }
+}
+
unsigned long mce_intel_adjust_timer(unsigned long interval)
{
if (interval < CMCI_POLL_INTERVAL)
@@ -90,6 +107,7 @@ unsigned long mce_intel_adjust_timer(unsigned long interval)
* timer interval is back to our poll interval.
*/
__this_cpu_write(cmci_storm_state, CMCI_STORM_SUBSIDED);
+ __this_cpu_write(cmci_storm_hcpu_status, CMCI_STORM_HCPU_NONE);
atomic_dec(&cmci_storm_on_cpus);

case CMCI_STORM_SUBSIDED:
@@ -119,6 +137,9 @@ static bool cmci_storm_detect(void)
unsigned long ts = __this_cpu_read(cmci_time_stamp);
unsigned long now = jiffies;

+ if (__this_cpu_read(cmci_storm_state) != CMCI_STORM_NONE)
+ return true;
+
if (time_before_eq(now, ts + CMCI_STORM_INTERVAL)) {
cnt++;
} else {
@@ -132,6 +153,7 @@ static bool cmci_storm_detect(void)

cmci_clear();
__this_cpu_write(cmci_storm_state, CMCI_STORM_ACTIVE);
+ __this_cpu_write(cmci_storm_hcpu_status, CMCI_STORM_HCPU_ACTIVE);
atomic_inc(&cmci_storm_on_cpus);
mce_timer_kick(CMCI_POLL_INTERVAL);
return true;
--
1.7.1

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