[PATCH 1/4] x86_64/i386 therm mce: Refactor thermal throttle processing

Dmitriy Zavin
2006-09-22T00:48:53Z

Refactor the event processing (syslog messaging and rate limiting)
into separate file therm_throt.c. This allows consistent reporting
of CPU thermal throttle events.

After ACK'ing the interrupt, if the event is current, the user
(p4.c/mce_intel.c) calls therm_throt_process to log (and rate limit)
the event. If that function returns 1, the user has the option to log
things further (such as to mce_log in x86_64).

Signed-off-by: Dmitriy Zavin <dmitriyz@google.com>

---
arch/i386/kernel/cpu/mcheck/Makefile | 2 +
arch/i386/kernel/cpu/mcheck/p4.c | 23 +++---------
arch/i386/kernel/cpu/mcheck/therm_throt.c | 58 +++++++++++++++++++++++++++++
arch/x86_64/kernel/Makefile | 4 +-
arch/x86_64/kernel/mce.c | 27 ++++++++++++++
arch/x86_64/kernel/mce_intel.c | 27 +++-----------
include/asm-i386/therm_throt.h | 6 +++
include/asm-x86_64/mce.h | 4 ++
include/asm-x86_64/therm_throt.h | 1 +
9 files changed, 111 insertions(+), 41 deletions(-)

diff --git a/arch/i386/kernel/cpu/mcheck/Makefile b/arch/i386/kernel/cpu/mcheck/Makefile
index 30808f3..f1ebe1c 100644
--- a/arch/i386/kernel/cpu/mcheck/Makefile
+++ b/arch/i386/kernel/cpu/mcheck/Makefile
@@ -1,2 +1,2 @@
-obj-y = mce.o k7.o p4.o p5.o p6.o winchip.o
+obj-y = mce.o k7.o p4.o p5.o p6.o winchip.o therm_throt.o
obj-$(CONFIG_X86_MCE_NONFATAL) += non-fatal.o
diff --git a/arch/i386/kernel/cpu/mcheck/p4.c b/arch/i386/kernel/cpu/mcheck/p4.c
index b95f1b3..d83a669 100644
--- a/arch/i386/kernel/cpu/mcheck/p4.c
+++ b/arch/i386/kernel/cpu/mcheck/p4.c
@@ -13,6 +13,8 @@ #include <asm/system.h>
#include <asm/msr.h>
#include <asm/apic.h>

+#include <asm/therm_throt.h>
+
#include "mce.h"

/* as supported by the P4/Xeon family */
@@ -44,25 +46,12 @@ static void unexpected_thermal_interrupt
/* P4/Xeon Thermal transition interrupt handler */
static void intel_thermal_interrupt(struct pt_regs *regs)
{
- u32 l, h;
- unsigned int cpu = smp_processor_id();
- static unsigned long next[NR_CPUS];
+ __u64 msr_val;

ack_APIC_irq();

- if (time_after(next[cpu], jiffies))
- return;
-
- next[cpu] = jiffies + HZ*5;
- rdmsr(MSR_IA32_THERM_STATUS, l, h);
- if (l & 0x1) {
- printk(KERN_EMERG "CPU%d: Temperature above threshold\n", cpu);
- printk(KERN_EMERG "CPU%d: Running in modulated clock mode\n",
- cpu);
- add_taint(TAINT_MACHINE_CHECK);
- } else {
- printk(KERN_INFO "CPU%d: Temperature/speed normal\n", cpu);
- }
+ rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
+ therm_throt_process(msr_val & 0x1);
}

/* Thermal interrupt handler for this CPU setup */
@@ -122,7 +111,7 @@ static void intel_init_thermal(struct cp

rdmsr (MSR_IA32_MISC_ENABLE, l, h);
wrmsr (MSR_IA32_MISC_ENABLE, l | (1<<3), h);
-
+
l = apic_read (APIC_LVTTHMR);
apic_write_around (APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
printk (KERN_INFO "CPU%d: Thermal monitoring enabled\n", cpu);
diff --git a/arch/i386/kernel/cpu/mcheck/therm_throt.c b/arch/i386/kernel/cpu/mcheck/therm_throt.c
new file mode 100644
index 0000000..85eba00
--- /dev/null
+++ b/arch/i386/kernel/cpu/mcheck/therm_throt.c
@@ -0,0 +1,58 @@
+/*
+ * linux/arch/i386/kerne/cpu/mcheck/therm_throt.c
+ *
+ * Thermal throttle event support code.
+ *
+ * Author: Dmitriy Zavin (dmitriyz@google.com)
+ *
+ * Credits: Adapted from Zwane Mwaikambo's original code in mce_intel.c.
+ *
+ */
+
+#include <linux/percpu.h>
+#include <linux/cpu.h>
+#include <asm/cpu.h>
+#include <linux/notifier.h>
+#include <asm/therm_throt.h>
+
+/* How long to wait between reporting thermal events */
+#define CHECK_INTERVAL (300 * HZ)
+
+static DEFINE_PER_CPU(unsigned long, next_check);
+
+/***
+ * therm_throt_process - Process thermal throttling event
+ * @curr: Whether the condition is current or not (boolean), since the
+ * thermal interrupt normally gets called both when the thermal
+ * event begins and once the event has ended.
+ *
+ * This function is normally called by the thermal interrupt after the
+ * IRQ has been acknowledged.
+ *
+ * It will take care of rate limiting and printing messages to the syslog.
+ *
+ * Returns: 0 : Event should NOT be further logged, i.e. still in
+ * "timeout" from previous log message.
+ * 1 : Event should be logged further, and a message has been
+ * printed to the syslog.
+ */
+int therm_throt_process(int curr)
+{
+ unsigned int cpu = smp_processor_id();
+
+ if (time_before(jiffies, __get_cpu_var(next_check)))
+ return 0;
+
+ __get_cpu_var(next_check) = jiffies + CHECK_INTERVAL;
+
+ /* if we just entered the thermal event */
+ if (curr) {
+ printk(KERN_CRIT "CPU%d: Temperature above threshold, "
+ "cpu clock throttled\n", cpu);
+ add_taint(TAINT_MACHINE_CHECK);
+ } else {
+ printk(KERN_CRIT "CPU%d: Temperature/speed normal\n", cpu);
+ }
+
+ return 1;
+}
diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile
index b5aaeaf..d97cec0 100644
--- a/arch/x86_64/kernel/Makefile
+++ b/arch/x86_64/kernel/Makefile
@@ -11,7 +11,7 @@ obj-y := process.o signal.o entry.o trap
pci-dma.o pci-nommu.o alternative.o

obj-$(CONFIG_STACKTRACE) += stacktrace.o
-obj-$(CONFIG_X86_MCE) += mce.o
+obj-$(CONFIG_X86_MCE) += mce.o therm_throt.o
obj-$(CONFIG_X86_MCE_INTEL) += mce_intel.o
obj-$(CONFIG_X86_MCE_AMD) += mce_amd.o
obj-$(CONFIG_MTRR) += ../../i386/kernel/cpu/mtrr/
@@ -45,6 +45,7 @@ obj-y += intel_cacheinfo.o

CFLAGS_vsyscall.o := $(PROFILING) -g0

+therm_throt-y += ../../i386/kernel/cpu/mcheck/therm_throt.o
bootflag-y += ../../i386/kernel/bootflag.o
cpuid-$(subst m,y,$(CONFIG_X86_CPUID)) += ../../i386/kernel/cpuid.o
topology-y += ../../i386/kernel/topology.o
@@ -54,4 +55,3 @@ quirks-y += ../../i386/kernel/quirks.o
i8237-y += ../../i386/kernel/i8237.o
msr-$(subst m,y,$(CONFIG_X86_MSR)) += ../../i386/kernel/msr.o
alternative-y += ../../i386/kernel/alternative.o
-
diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c
index 4e017fb..6314389 100644
--- a/arch/x86_64/kernel/mce.c
+++ b/arch/x86_64/kernel/mce.c
@@ -274,6 +274,33 @@ void do_machine_check(struct pt_regs * r
atomic_dec(&mce_entry);
}

+#ifdef CONFIG_X86_MCE_INTEL
+/***
+ * mce_log_therm_throt_event - Logs the thermal throttling event to mcelog
+ * @cpu: The CPU on which the event occured.
+ * @status: Event status information
+ *
+ * This function should be called by the thermal interrupt after the
+ * event has been processed and the decision was made to log the event
+ * further.
+ *
+ * The status parameter will be saved to the 'status' field of 'struct mce'
+ * and historically has been the register value of the
+ * MSR_IA32_THERMAL_STATUS (Intel) msr.
+ */
+void mce_log_therm_throt_event(unsigned int cpu, __u64 status)
+{
+ struct mce m;
+
+ memset(&m, 0, sizeof(m));
+ m.cpu = cpu;
+ m.bank = MCE_THERMAL_BANK;
+ m.status = status;
+ rdtscll(m.tsc);
+ mce_log(&m);
+}
+#endif /* CONFIG_X86_MCE_INTEL */
+
/*
* Periodic polling timer for "silent" machine check errors.
*/
diff --git a/arch/x86_64/kernel/mce_intel.c b/arch/x86_64/kernel/mce_intel.c
index 8f533d2..dec1121 100644
--- a/arch/x86_64/kernel/mce_intel.c
+++ b/arch/x86_64/kernel/mce_intel.c
@@ -11,36 +11,21 @@ #include <asm/msr.h>
#include <asm/mce.h>
#include <asm/hw_irq.h>
#include <asm/idle.h>
-
-static DEFINE_PER_CPU(unsigned long, next_check);
+#include <asm/therm_throt.h>

asmlinkage void smp_thermal_interrupt(void)
{
- struct mce m;
+ __u64 msr_val;

ack_APIC_irq();

exit_idle();
irq_enter();
- if (time_before(jiffies, __get_cpu_var(next_check)))
- goto done;
-
- __get_cpu_var(next_check) = jiffies + HZ*300;
- memset(&m, 0, sizeof(m));
- m.cpu = smp_processor_id();
- m.bank = MCE_THERMAL_BANK;
- rdtscll(m.tsc);
- rdmsrl(MSR_IA32_THERM_STATUS, m.status);
- if (m.status & 0x1) {
- printk(KERN_EMERG
- "CPU%d: Temperature above threshold, cpu clock throttled\n", m.cpu);
- add_taint(TAINT_MACHINE_CHECK);
- } else {
- printk(KERN_EMERG "CPU%d: Temperature/speed normal\n", m.cpu);
- }

- mce_log(&m);
-done:
+ rdmsrl(MSR_IA32_THERM_STATUS, msr_val);
+ if (therm_throt_process(msr_val & 1))
+ mce_log_therm_throt_event(smp_processor_id(), msr_val);
+
irq_exit();
}

diff --git a/include/asm-i386/therm_throt.h b/include/asm-i386/therm_throt.h
new file mode 100644
index 0000000..3c9c22c
--- /dev/null
+++ b/include/asm-i386/therm_throt.h
@@ -0,0 +1,6 @@
+#ifndef __ASM_I386_THERM_THROT_H__
+#define __ASM_I386_THERM_THROT_H__ 1
+
+int therm_throt_process(int curr);
+
+#endif /* __ASM_I386_THERM_THROT_H__ */
diff --git a/include/asm-x86_64/mce.h b/include/asm-x86_64/mce.h
index d13687d..5a0def5 100644
--- a/include/asm-x86_64/mce.h
+++ b/include/asm-x86_64/mce.h
@@ -99,6 +99,10 @@ static inline void mce_amd_feature_init(
}
#endif

+#ifdef CONFIG_X86_MCE_INTEL
+void mce_log_therm_throt_event(unsigned int cpu, __u64 status);
+#endif
+
extern atomic_t mce_entry;

#endif
diff --git a/include/asm-x86_64/therm_throt.h b/include/asm-x86_64/therm_throt.h
new file mode 100644
index 0000000..5aac059
--- /dev/null
+++ b/include/asm-x86_64/therm_throt.h
@@ -0,0 +1 @@
+#include <asm-i386/therm_throt.h>
--
1.4.2