Adding support to display hardware events translations available
through the sysfs. Adding 'events' group attribute under the sysfs
x86 PMU record with attribute/file for each hardware event.
This patch adds only backbone for PMUs to display config under
'events' directory. The specific PMU support itself will come
in next patches, however this is how the sysfs group will look
like:
# ls /sys/devices/cpu/events/
branch-instructions
branch-misses
bus-cycles
cache-misses
cache-references
cpu-cycles
instructions
ref-cycles
stalled-cycles-backend
stalled-cycles-frontend
The file - hw event ID mappings is:
file hw event ID
---------------------------------------------------------------
cpu-cycles PERF_COUNT_HW_CPU_CYCLES
instructions PERF_COUNT_HW_INSTRUCTIONS
cache-references PERF_COUNT_HW_CACHE_REFERENCES
cache-misses PERF_COUNT_HW_CACHE_MISSES
branch-instructions PERF_COUNT_HW_BRANCH_INSTRUCTIONS
branch-misses PERF_COUNT_HW_BRANCH_MISSES
bus-cycles PERF_COUNT_HW_BUS_CYCLES
stalled-cycles-frontend PERF_COUNT_HW_STALLED_CYCLES_FRONTEND
stalled-cycles-backend PERF_COUNT_HW_STALLED_CYCLES_BACKEND
ref-cycles PERF_COUNT_HW_REF_CPU_CYCLES
Each file in 'events' directory contains term translation for
the symbolic hw event for the currently running cpu model.
# cat /sys/devices/cpu/events/stalled-cycles-backend
event=0xb1,umask=0x01,inv,cmask=0x01
Suggested-by: Peter Zijlstra <a.p.zijls...@chello.nl>
Signed-off-by: Jiri Olsa <jo...@redhat.com>
Cc: Arnaldo Carvalho de Melo <a...@ghostprotocols.net>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Ingo Molnar <mi...@elte.hu>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Corey Ashford <cjash...@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Stephane Eranian <eran...@google.com>
---
arch/x86/kernel/cpu/perf_event.c | 60 ++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/cpu/perf_event.h | 2 ++
2 files changed, 62 insertions(+)
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 915b876..bff2eaa 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1308,6 +1308,62 @@ static struct attribute_group x86_pmu_format_group = {
.attrs = NULL,
};
+struct perf_pmu_events_attr {
+ struct device_attribute attr;
+ u64 id;
+};
+
+ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr,
+ char *page)
+{
+ struct perf_pmu_events_attr *pmu_attr = \
+ container_of(attr, struct perf_pmu_events_attr, attr);
+
+ u64 config = x86_pmu.event_map(pmu_attr->id);
+ return x86_pmu.events_sysfs_show(page, config);
+}
+
+#define EVENT_VAR(_id) event_attr_##_id
+#define EVENT_PTR(_id) &event_attr_##_id.attr.attr
+
+#define EVENT_ATTR(_name, _id) \
+static struct perf_pmu_events_attr EVENT_VAR(_id) = { \
+ .attr = __ATTR(_name, 0444, events_sysfs_show, NULL), \
+ .id = PERF_COUNT_HW_##_id, \
+};
+
+EVENT_ATTR(cpu-cycles, CPU_CYCLES );
+EVENT_ATTR(instructions, INSTRUCTIONS );
+EVENT_ATTR(cache-references, CACHE_REFERENCES );
+EVENT_ATTR(cache-misses, CACHE_MISSES );
+EVENT_ATTR(branch-instructions, BRANCH_INSTRUCTIONS );
+EVENT_ATTR(branch-misses, BRANCH_MISSES );
+EVENT_ATTR(bus-cycles, BUS_CYCLES );
+EVENT_ATTR(stalled-cycles-frontend, STALLED_CYCLES_FRONTEND );
+EVENT_ATTR(stalled-cycles-backend, STALLED_CYCLES_BACKEND );
+EVENT_ATTR(ref-cycles, REF_CPU_CYCLES );
+
+static struct attribute *empty_attrs;
+
+struct attribute *events_attr[] = {
+ EVENT_PTR(CPU_CYCLES),
+ EVENT_PTR(INSTRUCTIONS),
+ EVENT_PTR(CACHE_REFERENCES),
+ EVENT_PTR(CACHE_MISSES),
+ EVENT_PTR(BRANCH_INSTRUCTIONS),
+ EVENT_PTR(BRANCH_MISSES),
+ EVENT_PTR(BUS_CYCLES),
+ EVENT_PTR(STALLED_CYCLES_FRONTEND),
+ EVENT_PTR(STALLED_CYCLES_BACKEND),
+ EVENT_PTR(REF_CPU_CYCLES),
+ NULL,
+};
+
+static struct attribute_group x86_pmu_events_group = {
+ .name = "events",
+ .attrs = events_attr,
+};
+
static int __init init_hw_perf_events(void)
{
struct x86_pmu_quirk *quirk;
@@ -1354,6 +1410,9 @@ static int __init init_hw_perf_events(void)
x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */
x86_pmu_format_group.attrs = x86_pmu.format_attrs;
+ if (!x86_pmu.events_sysfs_show)
+ x86_pmu_events_group.attrs = &empty_attrs;
+
pr_info("... version: %d\n", x86_pmu.version);
pr_info("... bit width: %d\n", x86_pmu.cntval_bits);
pr_info("... generic registers: %d\n", x86_pmu.num_counters);
@@ -1643,6 +1702,7 @@ static struct attribute_group x86_pmu_attr_group = {
static const struct attribute_group *x86_pmu_attr_groups[] = {
&x86_pmu_attr_group,
&x86_pmu_format_group,
+ &x86_pmu_events_group,
NULL,
};
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 6605a81..63e223b 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -354,6 +354,8 @@ struct x86_pmu {
int attr_rdpmc;
struct attribute **format_attrs;
+ ssize_t (*events_sysfs_show)(char *page, u64 config);
+
/*
* CPU Hotplug hooks
*/
--
1.7.11.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
