[PATCH v1 1/2] perfevent: Add performance event structure definition and 'extevents' sysfs entry

Tomasz Fujak
2010-01-20T09:11:45Z

This patch adds a structure that contains single hardware performance event
definition (including name and description fields), and sysfs entry suited
to export machine-dependent list of events.

Signed-off-by: Tomasz Fujak <t.fujak@samsung.com>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>

---
include/linux/perf_event.h | 19 +++++++++++++++++++
kernel/perf_event.c | 32 ++++++++++++++++++++++++++++++++
2 files changed, 51 insertions(+), 0 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 9e70126..4dc4d73 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -447,6 +447,12 @@ enum perf_callchain_context {

#define PERF_MAX_STACK_DEPTH 255

+#define PERF_EVENT_RAW_BIT (1ULL << 63)
+#define PERF_EVENT_RAW_TO_CONFIG(_val) ((_val) | PERF_EVENT_RAW_BIT)
+#define PERF_EVENT_CONFIG_TO_RAW(_val) ((_val) & ~PERF_EVENT_RAW_BIT)
+#define PERF_EVENT_IS_RAW(_val) ((_val) & PERF_EVENT_RAW_BIT)
+
+
struct perf_callchain_entry {
__u64 nr;
__u64 ip[PERF_MAX_STACK_DEPTH];
@@ -538,6 +544,19 @@ struct perf_mmap_data {
void *data_pages[0];
};

+struct perf_event_description {
+ struct list_head list;
+
+ /* type : 1, subsystem [0..7], id [56..63]*/
+ __u64 config;
+ __u64 min_value; /* min. wakeup period */
+ __u64 max_value; /* max. wakeup period */
+ __u32 flags; /* ??? */
+ __u32 reserved[3];
+ char *name;
+ char *description;
+};
+
struct perf_pending_entry {
struct perf_pending_entry *next;
void (*func)(struct perf_pending_entry *);
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 7f29643..4223870 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -97,6 +97,13 @@ void __weak hw_perf_enable(void) { barrier(); }
void __weak hw_perf_event_setup(int cpu) { barrier(); }
void __weak hw_perf_event_setup_online(int cpu) { barrier(); }

+static LIST_HEAD(perf_event_empty);
+
+const struct list_head __weak *hw_perf_event_get_list(void)
+{
+ return &perf_event_empty;
+}
+
int __weak
hw_perf_group_sched_in(struct perf_event *group_leader,
struct perf_cpu_context *cpuctx,
@@ -5097,6 +5104,23 @@ perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count)
return count;
}

+static ssize_t perf_show_extevents(struct sysdev_class *class, char *buf)
+{
+ char *str = buf;
+ const struct list_head *head = hw_perf_event_get_list();
+ const struct perf_event_description *entry;
+
+ list_for_each_entry(entry, head, list)
+ if (PERF_EVENT_IS_RAW(entry->config))
+ str += sprintf(str, "0x%llx\t%s\t%lld-%lld\t%s\n",
+ PERF_EVENT_CONFIG_TO_RAW(entry->config),
+ entry->name, entry->min_value,
+ entry->max_value, entry->description);
+
+ return str - buf;
+}
+
+
static SYSDEV_CLASS_ATTR(
reserve_percpu,
0644,
@@ -5111,9 +5135,17 @@ static SYSDEV_CLASS_ATTR(
perf_set_overcommit
);

+static SYSDEV_CLASS_ATTR(
+ extevents,
+ 0444,
+ perf_show_extevents,
+ NULL
+ );
+
static struct attribute *perfclass_attrs[] = {
&attr_reserve_percpu.attr,
&attr_overcommit.attr,
+ &attr_extevents.attr,
NULL
};

--
1.5.4.3