Web lists-archives.com

[PATCH 3/8] perf/x86/cstate: Use new probe function




Using perf_msr_probe function to probe for cstate events.

The functionality is the same, with one exception, that
perf_msr_probe checks for rdmsr to return value != 0 for
given MSR register.

Using the new attribute groups and adding the events via
pmu::attr_update.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
 arch/x86/events/intel/cstate.c | 152 +++++++++++++++++++--------------
 1 file changed, 87 insertions(+), 65 deletions(-)

diff --git a/arch/x86/events/intel/cstate.c b/arch/x86/events/intel/cstate.c
index 6072f92cb8ea..df49097e4066 100644
--- a/arch/x86/events/intel/cstate.c
+++ b/arch/x86/events/intel/cstate.c
@@ -96,6 +96,7 @@
 #include <asm/cpu_device_id.h>
 #include <asm/intel-family.h>
 #include "../perf_event.h"
+#include "../probe.h"
 
 MODULE_LICENSE("GPL");
 
@@ -144,25 +145,42 @@ enum perf_cstate_core_events {
 	PERF_CSTATE_CORE_EVENT_MAX,
 };
 
-PMU_EVENT_ATTR_STRING(c1-residency, evattr_cstate_core_c1, "event=0x00");
-PMU_EVENT_ATTR_STRING(c3-residency, evattr_cstate_core_c3, "event=0x01");
-PMU_EVENT_ATTR_STRING(c6-residency, evattr_cstate_core_c6, "event=0x02");
-PMU_EVENT_ATTR_STRING(c7-residency, evattr_cstate_core_c7, "event=0x03");
+PMU_EVENT_ATTR_STRING(c1-residency, attr_cstate_core_c1, "event=0x00");
+PMU_EVENT_ATTR_STRING(c3-residency, attr_cstate_core_c3, "event=0x01");
+PMU_EVENT_ATTR_STRING(c6-residency, attr_cstate_core_c6, "event=0x02");
+PMU_EVENT_ATTR_STRING(c7-residency, attr_cstate_core_c7, "event=0x03");
 
-static struct perf_cstate_msr core_msr[] = {
-	[PERF_CSTATE_CORE_C1_RES] = { MSR_CORE_C1_RES,		&evattr_cstate_core_c1 },
-	[PERF_CSTATE_CORE_C3_RES] = { MSR_CORE_C3_RESIDENCY,	&evattr_cstate_core_c3 },
-	[PERF_CSTATE_CORE_C6_RES] = { MSR_CORE_C6_RESIDENCY,	&evattr_cstate_core_c6 },
-	[PERF_CSTATE_CORE_C7_RES] = { MSR_CORE_C7_RESIDENCY,	&evattr_cstate_core_c7 },
+static unsigned long core_msr_mask;
+
+PMU_EVENT_GROUP(events, cstate_core_c1);
+PMU_EVENT_GROUP(events, cstate_core_c3);
+PMU_EVENT_GROUP(events, cstate_core_c6);
+PMU_EVENT_GROUP(events, cstate_core_c7);
+
+static bool test_msr(int idx, void *data)
+{
+	return test_bit(idx, (unsigned long *) data);
+}
+
+static struct perf_msr core_msr[] = {
+	[PERF_CSTATE_CORE_C1_RES] = { MSR_CORE_C1_RES,		&group_cstate_core_c1,	test_msr },
+	[PERF_CSTATE_CORE_C3_RES] = { MSR_CORE_C3_RESIDENCY,	&group_cstate_core_c3,	test_msr },
+	[PERF_CSTATE_CORE_C6_RES] = { MSR_CORE_C6_RESIDENCY,	&group_cstate_core_c6,	test_msr },
+	[PERF_CSTATE_CORE_C7_RES] = { MSR_CORE_C7_RESIDENCY,	&group_cstate_core_c7,	test_msr },
 };
 
-static struct attribute *core_events_attrs[PERF_CSTATE_CORE_EVENT_MAX + 1] = {
+static struct attribute *attrs_empty[] = {
 	NULL,
 };
 
+/*
+ * There are no default events, but we need to create
+ * "events" group (with empty attrs) before updating
+ * it with detected events.
+ */
 static struct attribute_group core_events_attr_group = {
 	.name = "events",
-	.attrs = core_events_attrs,
+	.attrs = attrs_empty,
 };
 
 DEFINE_CSTATE_FORMAT_ATTR(core_event, event, "config:0-63");
@@ -211,31 +229,37 @@ enum perf_cstate_pkg_events {
 	PERF_CSTATE_PKG_EVENT_MAX,
 };
 
-PMU_EVENT_ATTR_STRING(c2-residency, evattr_cstate_pkg_c2, "event=0x00");
-PMU_EVENT_ATTR_STRING(c3-residency, evattr_cstate_pkg_c3, "event=0x01");
-PMU_EVENT_ATTR_STRING(c6-residency, evattr_cstate_pkg_c6, "event=0x02");
-PMU_EVENT_ATTR_STRING(c7-residency, evattr_cstate_pkg_c7, "event=0x03");
-PMU_EVENT_ATTR_STRING(c8-residency, evattr_cstate_pkg_c8, "event=0x04");
-PMU_EVENT_ATTR_STRING(c9-residency, evattr_cstate_pkg_c9, "event=0x05");
-PMU_EVENT_ATTR_STRING(c10-residency, evattr_cstate_pkg_c10, "event=0x06");
-
-static struct perf_cstate_msr pkg_msr[] = {
-	[PERF_CSTATE_PKG_C2_RES] = { MSR_PKG_C2_RESIDENCY,	&evattr_cstate_pkg_c2 },
-	[PERF_CSTATE_PKG_C3_RES] = { MSR_PKG_C3_RESIDENCY,	&evattr_cstate_pkg_c3 },
-	[PERF_CSTATE_PKG_C6_RES] = { MSR_PKG_C6_RESIDENCY,	&evattr_cstate_pkg_c6 },
-	[PERF_CSTATE_PKG_C7_RES] = { MSR_PKG_C7_RESIDENCY,	&evattr_cstate_pkg_c7 },
-	[PERF_CSTATE_PKG_C8_RES] = { MSR_PKG_C8_RESIDENCY,	&evattr_cstate_pkg_c8 },
-	[PERF_CSTATE_PKG_C9_RES] = { MSR_PKG_C9_RESIDENCY,	&evattr_cstate_pkg_c9 },
-	[PERF_CSTATE_PKG_C10_RES] = { MSR_PKG_C10_RESIDENCY,	&evattr_cstate_pkg_c10 },
-};
-
-static struct attribute *pkg_events_attrs[PERF_CSTATE_PKG_EVENT_MAX + 1] = {
-	NULL,
+PMU_EVENT_ATTR_STRING(c2-residency,  attr_cstate_pkg_c2,  "event=0x00");
+PMU_EVENT_ATTR_STRING(c3-residency,  attr_cstate_pkg_c3,  "event=0x01");
+PMU_EVENT_ATTR_STRING(c6-residency,  attr_cstate_pkg_c6,  "event=0x02");
+PMU_EVENT_ATTR_STRING(c7-residency,  attr_cstate_pkg_c7,  "event=0x03");
+PMU_EVENT_ATTR_STRING(c8-residency,  attr_cstate_pkg_c8,  "event=0x04");
+PMU_EVENT_ATTR_STRING(c9-residency,  attr_cstate_pkg_c9,  "event=0x05");
+PMU_EVENT_ATTR_STRING(c10-residency, attr_cstate_pkg_c10, "event=0x06");
+
+static unsigned long pkg_msr_mask;
+
+PMU_EVENT_GROUP(events, cstate_pkg_c2);
+PMU_EVENT_GROUP(events, cstate_pkg_c3);
+PMU_EVENT_GROUP(events, cstate_pkg_c6);
+PMU_EVENT_GROUP(events, cstate_pkg_c7);
+PMU_EVENT_GROUP(events, cstate_pkg_c8);
+PMU_EVENT_GROUP(events, cstate_pkg_c9);
+PMU_EVENT_GROUP(events, cstate_pkg_c10);
+
+static struct perf_msr pkg_msr[] = {
+	[PERF_CSTATE_PKG_C2_RES]  = { MSR_PKG_C2_RESIDENCY,	&group_cstate_pkg_c2,	test_msr },
+	[PERF_CSTATE_PKG_C3_RES]  = { MSR_PKG_C3_RESIDENCY,	&group_cstate_pkg_c3,	test_msr },
+	[PERF_CSTATE_PKG_C6_RES]  = { MSR_PKG_C6_RESIDENCY,	&group_cstate_pkg_c6,	test_msr },
+	[PERF_CSTATE_PKG_C7_RES]  = { MSR_PKG_C7_RESIDENCY,	&group_cstate_pkg_c7,	test_msr },
+	[PERF_CSTATE_PKG_C8_RES]  = { MSR_PKG_C8_RESIDENCY,	&group_cstate_pkg_c8,	test_msr },
+	[PERF_CSTATE_PKG_C9_RES]  = { MSR_PKG_C9_RESIDENCY,	&group_cstate_pkg_c9,	test_msr },
+	[PERF_CSTATE_PKG_C10_RES] = { MSR_PKG_C10_RESIDENCY,	&group_cstate_pkg_c10,	test_msr },
 };
 
 static struct attribute_group pkg_events_attr_group = {
 	.name = "events",
-	.attrs = pkg_events_attrs,
+	.attrs = attrs_empty,
 };
 
 DEFINE_CSTATE_FORMAT_ATTR(pkg_event, event, "config:0-63");
@@ -289,7 +313,8 @@ static int cstate_pmu_event_init(struct perf_event *event)
 	if (event->pmu == &cstate_core_pmu) {
 		if (cfg >= PERF_CSTATE_CORE_EVENT_MAX)
 			return -EINVAL;
-		if (!core_msr[cfg].attr)
+		cfg = array_index_nospec((unsigned long)cfg, PERF_CSTATE_CORE_EVENT_MAX);
+		if (!(core_msr_mask & (1 << cfg)))
 			return -EINVAL;
 		event->hw.event_base = core_msr[cfg].msr;
 		cpu = cpumask_any_and(&cstate_core_cpu_mask,
@@ -298,7 +323,7 @@ static int cstate_pmu_event_init(struct perf_event *event)
 		if (cfg >= PERF_CSTATE_PKG_EVENT_MAX)
 			return -EINVAL;
 		cfg = array_index_nospec((unsigned long)cfg, PERF_CSTATE_PKG_EVENT_MAX);
-		if (!pkg_msr[cfg].attr)
+		if (!(pkg_msr_mask & (1 << cfg)))
 			return -EINVAL;
 		event->hw.event_base = pkg_msr[cfg].msr;
 		cpu = cpumask_any_and(&cstate_pkg_cpu_mask,
@@ -421,8 +446,28 @@ static int cstate_cpu_init(unsigned int cpu)
 	return 0;
 }
 
+const struct attribute_group *core_attr_update[] = {
+	&group_cstate_core_c1,
+	&group_cstate_core_c3,
+	&group_cstate_core_c6,
+	&group_cstate_core_c7,
+	NULL,
+};
+
+const struct attribute_group *pkg_attr_update[] = {
+	&group_cstate_pkg_c2,
+	&group_cstate_pkg_c3,
+	&group_cstate_pkg_c6,
+	&group_cstate_pkg_c7,
+	&group_cstate_pkg_c8,
+	&group_cstate_pkg_c9,
+	&group_cstate_pkg_c10,
+	NULL,
+};
+
 static struct pmu cstate_core_pmu = {
 	.attr_groups	= core_attr_groups,
+	.attr_update	= core_attr_update,
 	.name		= "cstate_core",
 	.task_ctx_nr	= perf_invalid_context,
 	.event_init	= cstate_pmu_event_init,
@@ -437,6 +482,7 @@ static struct pmu cstate_core_pmu = {
 
 static struct pmu cstate_pkg_pmu = {
 	.attr_groups	= pkg_attr_groups,
+	.attr_update	= pkg_attr_update,
 	.name		= "cstate_pkg",
 	.task_ctx_nr	= perf_invalid_context,
 	.event_init	= cstate_pmu_event_init,
@@ -584,31 +630,6 @@ static const struct x86_cpu_id intel_cstates_match[] __initconst = {
 };
 MODULE_DEVICE_TABLE(x86cpu, intel_cstates_match);
 
-/*
- * Probe the cstate events and insert the available one into sysfs attrs
- * Return false if there are no available events.
- */
-static bool __init cstate_probe_msr(const unsigned long evmsk, int max,
-                                   struct perf_cstate_msr *msr,
-                                   struct attribute **attrs)
-{
-	bool found = false;
-	unsigned int bit;
-	u64 val;
-
-	for (bit = 0; bit < max; bit++) {
-		if (test_bit(bit, &evmsk) && !rdmsrl_safe(msr[bit].msr, &val)) {
-			*attrs++ = &msr[bit].attr->attr.attr;
-			found = true;
-		} else {
-			msr[bit].attr = NULL;
-		}
-	}
-	*attrs = NULL;
-
-	return found;
-}
-
 static int __init cstate_probe(const struct cstate_model *cm)
 {
 	/* SLM has different MSR for PKG C6 */
@@ -620,13 +641,14 @@ static int __init cstate_probe(const struct cstate_model *cm)
 		pkg_msr[PERF_CSTATE_CORE_C6_RES].msr = MSR_KNL_CORE_C6_RESIDENCY;
 
 
-	has_cstate_core = cstate_probe_msr(cm->core_events,
-					   PERF_CSTATE_CORE_EVENT_MAX,
-					   core_msr, core_events_attrs);
+	core_msr_mask = perf_msr_probe(core_msr, PERF_CSTATE_CORE_EVENT_MAX,
+				       true, (void *) &cm->core_events);
+
+	pkg_msr_mask = perf_msr_probe(pkg_msr, PERF_CSTATE_PKG_EVENT_MAX,
+				      true, (void *) &cm->pkg_events);
 
-	has_cstate_pkg = cstate_probe_msr(cm->pkg_events,
-					  PERF_CSTATE_PKG_EVENT_MAX,
-					  pkg_msr, pkg_events_attrs);
+	has_cstate_core = !!core_msr_mask;
+	has_cstate_pkg  = !!pkg_msr_mask;
 
 	return (has_cstate_core || has_cstate_pkg) ? 0 : -ENODEV;
 }
-- 
2.21.0