Do not exit on MSR read errors

PATCH New Jaroslav Škarvada <jskarvad at redhat.com> 4 participants 5 messages May 11, 2015 – Sep 16, 2015

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Jaroslav Škarvada <jskarvad at redhat.com>

2015-05-11 14:32 UTC #0 lore raw

PATCH 1/1 Do not exit on MSR read errors

There are virtual environments not correctly implementing the MSR (e.g. VirtualBox bug: https://www.virtualbox.org/ticket/14099) or not implementing it at all (e.g. KVM). PowerTOP just exits in such environments and cannot run.

The proposed patch makes PowerTOP not to exit on MSR read errors, but still report them.

Signed-off-by Jaroslav Škarvada <jskarvad(a)redhat.com>

---
 src/cpu/intel_cpus.cpp | 103 +++++++++++++++++++++++++++++--------------------
 src/cpu/intel_cpus.h   |   1 +
 2 files changed, 62 insertions(+), 42 deletions(-)

src/cpu/intel_cpus.cpp +61 ~~-42~~

index 1f3647a..69fdc84 100644
@@ -79,20 +79,20 @@ int is_supported_intel_cpu(int model)
 	return 0;
 }
 
-static uint64_t get_msr(int cpu, uint64_t offset)
+static int get_msr(int cpu, uint64_t offset, uint64_t *msr)
 {
 	ssize_t retval;
-	uint64_t msr;
 
-	retval = read_msr(cpu, offset, &msr);
+	retval = read_msr(cpu, offset, msr);
 	if (retval < 0) {
 		reset_display();
 		fprintf(stderr, _("read_msr cpu%d 0x%llx : "), cpu, (unsigned long long)offset);
 		fprintf(stderr, "%s\n", strerror(errno));
-		exit(-2);
+		*msr = 0;
+		return 0;
 	}
 
-	return msr;
+	return 1;
 }
 
 intel_util::intel_util()

@@ -152,13 +152,18 @@ void nhm_core::measurement_start(void)
 	last_stamp = 0;
 
 	if (this->has_c1_res)
-		c1_before = get_msr(first_cpu, MSR_CORE_C1_RESIDENCY);
+		if (!get_msr(first_cpu, MSR_CORE_C1_RESIDENCY, &c1_before))
+			this->has_c1_res = 0;
 	if (this->has_c3_res)
-		c3_before    = get_msr(first_cpu, MSR_CORE_C3_RESIDENCY);
-	c6_before    = get_msr(first_cpu, MSR_CORE_C6_RESIDENCY);
+		if (!get_msr(first_cpu, MSR_CORE_C3_RESIDENCY, &c3_before))
+			this->has_c3_res = 0;
+	if (this->has_c6_res)
+		if (!get_msr(first_cpu, MSR_CORE_C6_RESIDENCY, &c6_before))
+			this->has_c6_res = 0;
 	if (this->has_c7_res)
-		c7_before    = get_msr(first_cpu, MSR_CORE_C7_RESIDENCY);
-	tsc_before   = get_msr(first_cpu, MSR_TSC);
+		if (!get_msr(first_cpu, MSR_CORE_C7_RESIDENCY, &c7_before))
+			this->has_c7_res = 0;
+	get_msr(first_cpu, MSR_TSC, &tsc_before);
 
 	if (this->has_c1_res)
 		insert_cstate("core c1", "C1 (cc1)", 0, c1_before, 1);

@@ -196,13 +201,18 @@ void nhm_core::measurement_end(void)
 	double ratio;
 
 	if (this->has_c1_res)
-		c1_after = get_msr(first_cpu, MSR_CORE_C1_RESIDENCY);
+		if (!get_msr(first_cpu, MSR_CORE_C1_RESIDENCY, &c1_after))
+			this->has_c1_res = 0;
 	if (this->has_c3_res)
-		c3_after    = get_msr(first_cpu, MSR_CORE_C3_RESIDENCY);
-	c6_after    = get_msr(first_cpu, MSR_CORE_C6_RESIDENCY);
+		if (!get_msr(first_cpu, MSR_CORE_C3_RESIDENCY, &c3_after))
+			this->has_c3_res = 0;
+	if (this->has_c6_res)
+		if (!get_msr(first_cpu, MSR_CORE_C6_RESIDENCY, &c6_after))
+			this->has_c6_res = 0;
 	if (this->has_c7_res)
-		c7_after    = get_msr(first_cpu, MSR_CORE_C7_RESIDENCY);
-	tsc_after   = get_msr(first_cpu, MSR_TSC);
+		if (!get_msr(first_cpu, MSR_CORE_C7_RESIDENCY, &c7_after))
+			this->has_c7_res = 0;
+	get_msr(first_cpu, MSR_TSC, &tsc_after);
 
 	if (this->has_c1_res)
 		finalize_cstate("core c1", 0, c1_after, 1);

@@ -360,27 +370,31 @@ void nhm_package::measurement_start(void)
 	last_stamp = 0;
 
 	if (this->has_c2c6_res)
-		c2_before    = get_msr(number, MSR_PKG_C2_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C2_RESIDENCY, &c2_before))
+			this->has_c2c6_res = 0;
 
 	if (this->has_c3_res)
-		c3_before    = get_msr(number, MSR_PKG_C3_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C3_RESIDENCY, &c3_before))
+			this->has_c3_res = 0;
 
 	/*
 	 * Hack for Braswell where C7 MSR is actually BSW C6
 	 */
 	if (this->has_c6c_res)
-		c6_before    = get_msr(number, MSR_PKG_C7_RESIDENCY);
+		get_msr(number, MSR_PKG_C7_RESIDENCY, &c6_before);
 	else
-		c6_before    = get_msr(number, MSR_PKG_C6_RESIDENCY);
+		get_msr(number, MSR_PKG_C6_RESIDENCY, &c6_before);
 
 	if (this->has_c7_res)
-		c7_before    = get_msr(number, MSR_PKG_C7_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C7_RESIDENCY, &c7_before))
+			this->has_c7_res = 0;
 	if (this->has_c8c9c10_res) {
-		c8_before    = get_msr(number, MSR_PKG_C8_RESIDENCY);
-		c9_before    = get_msr(number, MSR_PKG_C9_RESIDENCY);
-		c10_before    = get_msr(number, MSR_PKG_C10_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C8_RESIDENCY, &c8_before) ||
+		    !get_msr(number, MSR_PKG_C9_RESIDENCY, &c9_before) ||
+		    !get_msr(number, MSR_PKG_C10_RESIDENCY, &c10_before))
+			this->has_c8c9c10_res = 0;
 	}
-	tsc_before   = get_msr(first_cpu, MSR_TSC);
+	get_msr(first_cpu, MSR_TSC, &tsc_before);
 
 	if (this->has_c2c6_res)
 		insert_cstate("pkg c2", "C2 (pc2)", 0, c2_before, 1);

@@ -409,24 +423,28 @@ void nhm_package::measurement_end(void)
 
 
 	if (this->has_c2c6_res)
-		c2_after    = get_msr(number, MSR_PKG_C2_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C2_RESIDENCY, &c2_after))
+			this->has_c2c6_res = 0;
 
 	if (this->has_c3_res)
-		c3_after    = get_msr(number, MSR_PKG_C3_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C3_RESIDENCY, &c3_after))
+			this->has_c3_res = 0;
 
 	if (this->has_c6c_res)
-		c6_after    = get_msr(number, MSR_PKG_C7_RESIDENCY);
+		get_msr(number, MSR_PKG_C7_RESIDENCY, &c6_after);
 	else
-		c6_after    = get_msr(number, MSR_PKG_C6_RESIDENCY);
+		get_msr(number, MSR_PKG_C6_RESIDENCY, &c6_after);
 
 	if (this->has_c7_res)
-		c7_after    = get_msr(number, MSR_PKG_C7_RESIDENCY);
-	if (has_c8c9c10_res) {
-		c8_after = get_msr(number, MSR_PKG_C8_RESIDENCY);
-		c9_after = get_msr(number, MSR_PKG_C9_RESIDENCY);
-		c10_after = get_msr(number, MSR_PKG_C10_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C7_RESIDENCY, &c7_after))
+			this->has_c7_res = 0;
+	if (this->has_c8c9c10_res) {
+		if (!get_msr(number, MSR_PKG_C8_RESIDENCY, &c8_after) ||
+		    !get_msr(number, MSR_PKG_C9_RESIDENCY, &c9_after) ||
+		    !get_msr(number, MSR_PKG_C10_RESIDENCY, &c10_after))
+			this->has_c8c9c10_res = 0;
 	}
-	tsc_after   = get_msr(first_cpu, MSR_TSC);
+	get_msr(first_cpu, MSR_TSC, &tsc_after);
 
 	gettimeofday(&stamp_after, NULL);

@@ -441,7 +459,7 @@ void nhm_package::measurement_end(void)
 	finalize_cstate("pkg c6", 0, c6_after, 1);
 	if (this->has_c7_res)
 		finalize_cstate("pkg c7", 0, c7_after, 1);
-	if (has_c8c9c10_res) {
+	if (this->has_c8c9c10_res) {
 		finalize_cstate("pkg c8", 0, c8_after, 1);
 		finalize_cstate("pkg c9", 0, c9_after, 1);
 		finalize_cstate("pkg c10", 0, c10_after, 1);

@@ -497,9 +515,9 @@ void nhm_cpu::measurement_start(void)
 
 	last_stamp = 0;
 
-	aperf_before = get_msr(number, MSR_APERF);
-	mperf_before = get_msr(number, MSR_MPERF);
-	tsc_before   = get_msr(number, MSR_TSC);
+	get_msr(number, MSR_APERF, &aperf_before);
+	get_msr(number, MSR_MPERF, &mperf_before);
+	get_msr(number, MSR_TSC, &tsc_before);
 
 	insert_cstate("active", _("C0 active"), 0, aperf_before, 1);

@@ -527,9 +545,9 @@ void nhm_cpu::measurement_end(void)
 	double ratio;
 	unsigned int i;
 
-	aperf_after = get_msr(number, MSR_APERF);
-	mperf_after = get_msr(number, MSR_MPERF);
-	tsc_after   = get_msr(number, MSR_TSC);
+	get_msr(number, MSR_APERF, &aperf_after);
+	get_msr(number, MSR_MPERF, &mperf_after);
+	get_msr(number, MSR_TSC, &tsc_after);

@@ -582,7 +600,8 @@ char * nhm_cpu::fill_pstate_line(int line_nr, char *buffer)
 
 	if (line_nr == LEVEL_C0) {
 		double F;
-		F = 1.0 * (tsc_after - tsc_before) * (aperf_after - aperf_before) / (mperf_after - mperf_before) / time_factor * 1000;
+		F = mperf_after - mperf_before;
+		F = 1.0 * (tsc_after - tsc_before) * (aperf_after - aperf_before) / (F ? F : 1) / time_factor * 1000;
 		hz_to_human(F, buffer, 1);
 		return buffer;
 	}

src/cpu/intel_cpus.h +1 -0

index 0331069..e909018 100644
@@ -100,6 +100,7 @@ private:
 	uint64_t	total_stamp;
 public:
 	int		has_c1_res;
+	int		has_c6_res = 1;
 	int		has_c7_res;
 	int		has_c3_res;
 	nhm_core(int model);

Signature · 1 line

2.1.0

Jaroslav Skarvada

2015-05-11 16:49 UTC #1 lore raw

PATCH 1/1 Do not exit on MSR read errors

Hi,

it seems there are virtual environments not correctly implementing the MSR (e.g. VirtualBox bug: https://www.virtualbox.org/ticket/14099) or not implementing it at all (e.g. KVM). PowerTOP just exits in such environments and cannot run.

The proposed patch makes PowerTOP not to exit on MSR read errors, but still report them.

Resending as attachment, because the previous e-mail has been probably blocked somewhere

thanks & regards

Jaroslav

From ef45eb882274e14c60920a433a665c3695e685e7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jaroslav=20=C5=A0karvada?= <[email protected]>
Date: Thu, 7 May 2015 17:11:43 +0200
Subject: [PATCH] Do not exit on MSR read errors
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The proposed patch makes PowerTOP not to exit on MSR read errors, but still report them.

Signed-off-by Jaroslav Škarvada <[email protected]>

---
 src/cpu/intel_cpus.cpp | 103 +++++++++++++++++++++++++++++--------------------
 src/cpu/intel_cpus.h   |   1 +
 2 files changed, 62 insertions(+), 42 deletions(-)

src/cpu/intel_cpus.cpp +61 ~~-42~~

index 1f3647a..69fdc84 100644
@@ -79,20 +79,20 @@ int is_supported_intel_cpu(int model)
 	return 0;
 }
 
-static uint64_t get_msr(int cpu, uint64_t offset)
+static int get_msr(int cpu, uint64_t offset, uint64_t *msr)
 {
 	ssize_t retval;
-	uint64_t msr;
 
-	retval = read_msr(cpu, offset, &msr);
+	retval = read_msr(cpu, offset, msr);
 	if (retval < 0) {
 		reset_display();
 		fprintf(stderr, _("read_msr cpu%d 0x%llx : "), cpu, (unsigned long long)offset);
 		fprintf(stderr, "%s\n", strerror(errno));
-		exit(-2);
+		*msr = 0;
+		return 0;
 	}
 
-	return msr;
+	return 1;
 }
 
 intel_util::intel_util()

@@ -152,13 +152,18 @@ void nhm_core::measurement_start(void)
 	last_stamp = 0;
 
 	if (this->has_c1_res)
-		c1_before = get_msr(first_cpu, MSR_CORE_C1_RESIDENCY);
+		if (!get_msr(first_cpu, MSR_CORE_C1_RESIDENCY, &c1_before))
+			this->has_c1_res = 0;
 	if (this->has_c3_res)
-		c3_before    = get_msr(first_cpu, MSR_CORE_C3_RESIDENCY);
-	c6_before    = get_msr(first_cpu, MSR_CORE_C6_RESIDENCY);
+		if (!get_msr(first_cpu, MSR_CORE_C3_RESIDENCY, &c3_before))
+			this->has_c3_res = 0;
+	if (this->has_c6_res)
+		if (!get_msr(first_cpu, MSR_CORE_C6_RESIDENCY, &c6_before))
+			this->has_c6_res = 0;
 	if (this->has_c7_res)
-		c7_before    = get_msr(first_cpu, MSR_CORE_C7_RESIDENCY);
-	tsc_before   = get_msr(first_cpu, MSR_TSC);
+		if (!get_msr(first_cpu, MSR_CORE_C7_RESIDENCY, &c7_before))
+			this->has_c7_res = 0;
+	get_msr(first_cpu, MSR_TSC, &tsc_before);
 
 	if (this->has_c1_res)
 		insert_cstate("core c1", "C1 (cc1)", 0, c1_before, 1);

@@ -196,13 +201,18 @@ void nhm_core::measurement_end(void)
 	double ratio;
 
 	if (this->has_c1_res)
-		c1_after = get_msr(first_cpu, MSR_CORE_C1_RESIDENCY);
+		if (!get_msr(first_cpu, MSR_CORE_C1_RESIDENCY, &c1_after))
+			this->has_c1_res = 0;
 	if (this->has_c3_res)
-		c3_after    = get_msr(first_cpu, MSR_CORE_C3_RESIDENCY);
-	c6_after    = get_msr(first_cpu, MSR_CORE_C6_RESIDENCY);
+		if (!get_msr(first_cpu, MSR_CORE_C3_RESIDENCY, &c3_after))
+			this->has_c3_res = 0;
+	if (this->has_c6_res)
+		if (!get_msr(first_cpu, MSR_CORE_C6_RESIDENCY, &c6_after))
+			this->has_c6_res = 0;
 	if (this->has_c7_res)
-		c7_after    = get_msr(first_cpu, MSR_CORE_C7_RESIDENCY);
-	tsc_after   = get_msr(first_cpu, MSR_TSC);
+		if (!get_msr(first_cpu, MSR_CORE_C7_RESIDENCY, &c7_after))
+			this->has_c7_res = 0;
+	get_msr(first_cpu, MSR_TSC, &tsc_after);
 
 	if (this->has_c1_res)
 		finalize_cstate("core c1", 0, c1_after, 1);

@@ -360,27 +370,31 @@ void nhm_package::measurement_start(void)
 	last_stamp = 0;
 
 	if (this->has_c2c6_res)
-		c2_before    = get_msr(number, MSR_PKG_C2_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C2_RESIDENCY, &c2_before))
+			this->has_c2c6_res = 0;
 
 	if (this->has_c3_res)
-		c3_before    = get_msr(number, MSR_PKG_C3_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C3_RESIDENCY, &c3_before))
+			this->has_c3_res = 0;
 
 	/*
 	 * Hack for Braswell where C7 MSR is actually BSW C6
 	 */
 	if (this->has_c6c_res)
-		c6_before    = get_msr(number, MSR_PKG_C7_RESIDENCY);
+		get_msr(number, MSR_PKG_C7_RESIDENCY, &c6_before);
 	else
-		c6_before    = get_msr(number, MSR_PKG_C6_RESIDENCY);
+		get_msr(number, MSR_PKG_C6_RESIDENCY, &c6_before);
 
 	if (this->has_c7_res)
-		c7_before    = get_msr(number, MSR_PKG_C7_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C7_RESIDENCY, &c7_before))
+			this->has_c7_res = 0;
 	if (this->has_c8c9c10_res) {
-		c8_before    = get_msr(number, MSR_PKG_C8_RESIDENCY);
-		c9_before    = get_msr(number, MSR_PKG_C9_RESIDENCY);
-		c10_before    = get_msr(number, MSR_PKG_C10_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C8_RESIDENCY, &c8_before) ||
+		    !get_msr(number, MSR_PKG_C9_RESIDENCY, &c9_before) ||
+		    !get_msr(number, MSR_PKG_C10_RESIDENCY, &c10_before))
+			this->has_c8c9c10_res = 0;
 	}
-	tsc_before   = get_msr(first_cpu, MSR_TSC);
+	get_msr(first_cpu, MSR_TSC, &tsc_before);
 
 	if (this->has_c2c6_res)
 		insert_cstate("pkg c2", "C2 (pc2)", 0, c2_before, 1);

@@ -409,24 +423,28 @@ void nhm_package::measurement_end(void)
 
 
 	if (this->has_c2c6_res)
-		c2_after    = get_msr(number, MSR_PKG_C2_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C2_RESIDENCY, &c2_after))
+			this->has_c2c6_res = 0;
 
 	if (this->has_c3_res)
-		c3_after    = get_msr(number, MSR_PKG_C3_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C3_RESIDENCY, &c3_after))
+			this->has_c3_res = 0;
 
 	if (this->has_c6c_res)
-		c6_after    = get_msr(number, MSR_PKG_C7_RESIDENCY);
+		get_msr(number, MSR_PKG_C7_RESIDENCY, &c6_after);
 	else
-		c6_after    = get_msr(number, MSR_PKG_C6_RESIDENCY);
+		get_msr(number, MSR_PKG_C6_RESIDENCY, &c6_after);
 
 	if (this->has_c7_res)
-		c7_after    = get_msr(number, MSR_PKG_C7_RESIDENCY);
-	if (has_c8c9c10_res) {
-		c8_after = get_msr(number, MSR_PKG_C8_RESIDENCY);
-		c9_after = get_msr(number, MSR_PKG_C9_RESIDENCY);
-		c10_after = get_msr(number, MSR_PKG_C10_RESIDENCY);
+		if (!get_msr(number, MSR_PKG_C7_RESIDENCY, &c7_after))
+			this->has_c7_res = 0;
+	if (this->has_c8c9c10_res) {
+		if (!get_msr(number, MSR_PKG_C8_RESIDENCY, &c8_after) ||
+		    !get_msr(number, MSR_PKG_C9_RESIDENCY, &c9_after) ||
+		    !get_msr(number, MSR_PKG_C10_RESIDENCY, &c10_after))
+			this->has_c8c9c10_res = 0;
 	}
-	tsc_after   = get_msr(first_cpu, MSR_TSC);
+	get_msr(first_cpu, MSR_TSC, &tsc_after);
 
 	gettimeofday(&stamp_after, NULL);

@@ -441,7 +459,7 @@ void nhm_package::measurement_end(void)
 	finalize_cstate("pkg c6", 0, c6_after, 1);
 	if (this->has_c7_res)
 		finalize_cstate("pkg c7", 0, c7_after, 1);
-	if (has_c8c9c10_res) {
+	if (this->has_c8c9c10_res) {
 		finalize_cstate("pkg c8", 0, c8_after, 1);
 		finalize_cstate("pkg c9", 0, c9_after, 1);
 		finalize_cstate("pkg c10", 0, c10_after, 1);

@@ -497,9 +515,9 @@ void nhm_cpu::measurement_start(void)
 
 	last_stamp = 0;
 
-	aperf_before = get_msr(number, MSR_APERF);
-	mperf_before = get_msr(number, MSR_MPERF);
-	tsc_before   = get_msr(number, MSR_TSC);
+	get_msr(number, MSR_APERF, &aperf_before);
+	get_msr(number, MSR_MPERF, &mperf_before);
+	get_msr(number, MSR_TSC, &tsc_before);
 
 	insert_cstate("active", _("C0 active"), 0, aperf_before, 1);

@@ -527,9 +545,9 @@ void nhm_cpu::measurement_end(void)
 	double ratio;
 	unsigned int i;
 
-	aperf_after = get_msr(number, MSR_APERF);
-	mperf_after = get_msr(number, MSR_MPERF);
-	tsc_after   = get_msr(number, MSR_TSC);
+	get_msr(number, MSR_APERF, &aperf_after);
+	get_msr(number, MSR_MPERF, &mperf_after);
+	get_msr(number, MSR_TSC, &tsc_after);

@@ -582,7 +600,8 @@ char * nhm_cpu::fill_pstate_line(int line_nr, char *buffer)
 
 	if (line_nr == LEVEL_C0) {
 		double F;
-		F = 1.0 * (tsc_after - tsc_before) * (aperf_after - aperf_before) / (mperf_after - mperf_before) / time_factor * 1000;
+		F = mperf_after - mperf_before;
+		F = 1.0 * (tsc_after - tsc_before) * (aperf_after - aperf_before) / (F ? F : 1) / time_factor * 1000;
 		hz_to_human(F, buffer, 1);
 		return buffer;
 	}

src/cpu/intel_cpus.h +1 -0

index 0331069..e909018 100644
@@ -100,6 +100,7 @@ private:
 	uint64_t	total_stamp;
 public:
 	int		has_c1_res;
+	int		has_c6_res = 1;
 	int		has_c7_res;
 	int		has_c3_res;
 	nhm_core(int model);

Signature · 1 line

2.1.0

Arjan van de Ven

2015-05-11 16:54 UTC #2 lore raw

Quoted 6 lines · Jaroslav Skarvada

Hi,
it seems there are virtual environments not correctly implementing the MSR (e.g. VirtualBox bug: https://www.virtualbox.org/ticket/14099) or not implementing it at all (e.g. KVM). PowerTOP just exits in such environments and cannot run.

Quoted 6 lines

The proposed patch makes PowerTOP not to exit on MSR read errors, but still report them.
Resending as attachment, because the previous e-mail has been probably blocked somewhere

Hi,

I have a slightly different patch in a local repo, but it needed a command line option so I didn't sent it upstream yet.

the solution you have makes the app not crash, but it's really not the right thing. the reason is that the statistics code still uses the "native intel msr" model, so it gets all zeroes... it should use "just trust the kernel" model instead.

- if (strcmp(vendor, "GenuineIntel") == 0)
+ if (strcmp(vendor, "GenuineIntel") == 0 && !broken_msrs)

something like that in src/cpu/cpu.cpp (3x) is needed instead.... but today the msr logic runs after this code, not before, so I have not yet found a good way to set the broken_msrs variable for the case in question

Alexandra Yates

2015-09-16 19:19 UTC #3 lore raw

Hi Jaroslav,

Quoted 4 lines · Arjan van de Ven

but it's really not the right thing.
the reason is that the statistics code still uses the "native intel msr" model,
so it gets all zeroes... it should use "just trust the kernel" model in

Based on Arjan's feedback do you have a change for this patch? Otherwise I would have to reject it.

I'm also looking into all other submitted patches.

Signature · 2 lines

Thank you,
<Alexandra>

Arjan van de Ven

2015-09-16 19:31 UTC #4 lore raw

Quoted 7 lines · Alexandra Yates

Hi Jaroslav,
Quoted 3 lines · Arjan van de Ven
but it's really not the right thing.
the reason is that the statistics code still uses the "native intel msr" model, so it gets all zeroes... it should use "just trust the kernel" model in
Based on Arjan's feedback do you have a change for this patch? Otherwise I would have to reject it.

we do need to solve this problem... it's real. just we need to really solve it, not just a workaround.

is not insane hard (we'd need to do a test read msr, if that fails because of broken virtualization, fall back to the degraded mode automatically)