[PATCH 09/16] perf, persistent: Introduce get_persistent_event()

From: Robert Richter
Date: Fri May 31 2013 - 04:51:09 EST


From: Robert Richter <robert.richter@xxxxxxxxxxx>

Reducing duplicate code by introducing function get_persistent_event()
to get the descriptor of an persistent event.

Signed-off-by: Robert Richter <robert.richter@xxxxxxxxxxx>
---
kernel/events/persistent.c | 37 ++++++++++++++++++++++---------------
1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/kernel/events/persistent.c b/kernel/events/persistent.c
index ff1ce3b..7d1aff3 100644
--- a/kernel/events/persistent.c
+++ b/kernel/events/persistent.c
@@ -16,6 +16,19 @@ struct pers_event_desc {

static DEFINE_PER_CPU(struct list_head, pers_events);

+static struct pers_event_desc
+*get_persistent_event(int cpu, struct perf_event_attr *attr)
+{
+ struct pers_event_desc *desc;
+
+ list_for_each_entry(desc, &per_cpu(pers_events, cpu), plist) {
+ if (desc->event->attr.config == attr->config)
+ return desc;
+ }
+
+ return NULL;
+}
+
static struct perf_event *
add_persistent_event_on_cpu(unsigned int cpu, struct perf_event_attr *attr,
unsigned nr_pages)
@@ -58,18 +71,13 @@ out:

static void del_persistent_event(int cpu, struct perf_event_attr *attr)
{
- struct pers_event_desc *desc, *tmp;
- struct perf_event *event = NULL;
-
- list_for_each_entry_safe(desc, tmp, &per_cpu(pers_events, cpu), plist) {
- if (desc->event->attr.config == attr->config) {
- event = desc->event;
- break;
- }
- }
+ struct pers_event_desc *desc;
+ struct perf_event *event;

- if (!event)
+ desc = get_persistent_event(cpu, attr);
+ if (!desc)
return;
+ event = desc->event;

list_del(&desc->plist);

@@ -156,13 +164,12 @@ int perf_add_persistent_event_by_id(int id)

int perf_get_persistent_event_fd(unsigned cpu, struct perf_event_attr *attr)
{
- struct pers_event_desc *desc;
+ struct pers_event_desc *desc = get_persistent_event(cpu, attr);

- list_for_each_entry(desc, &per_cpu(pers_events, cpu), plist)
- if (desc->event->attr.config == attr->config)
- return __alloc_persistent_event_fd(desc);
+ if (!desc)
+ return -ENODEV;

- return -ENODEV;
+ return __alloc_persistent_event_fd(desc);
}


--
1.8.1.1

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