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

Jiri Olsa
2019-05-31T12:10:29Z

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@kernel.org>
---
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