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Subject[RFC PATCH 4/4] bpf tools: Enable/disable the perf events stored in 'struct bpf_object'
Date
This patch enable/disable the perf events stored in 'struct
bpf_object' at the appropriate time. These events we're
interested in come from 'maps' sections.

Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
---
tools/lib/bpf/libbpf.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 2b3940e..7fab959 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -20,6 +20,7 @@
#include <linux/list.h>
#include <libelf.h>
#include <gelf.h>
+#include <sys/ioctl.h>

#include "libbpf.h"
#include "bpf.h"
@@ -972,6 +973,32 @@ bpf_object__load_progs(struct bpf_object *obj)
return 0;
}

+static int
+bpf_object__maps_event_enable(struct bpf_object *obj)
+{
+ int i;
+ int nr_bpf_event = obj->nr_bpf_event_fds;
+
+ for (i = 0; i < nr_bpf_event; i++)
+ ioctl((int)obj->bpf_event_fds[i],
+ PERF_EVENT_IOC_ENABLE, 0);
+
+ return 0;
+}
+
+static void bpf_object__maps_event_close(struct bpf_object *obj)
+{
+ int i;
+ int nr_bpf_event = obj->nr_bpf_event_fds;
+
+ for (i = 0; i < nr_bpf_event; i++) {
+ int maps_event_fd = (int)obj->bpf_event_fds[i];
+
+ ioctl(maps_event_fd, PERF_EVENT_IOC_DISABLE, 0);
+ close(maps_event_fd);
+ }
+}
+
static int bpf_object__validate(struct bpf_object *obj)
{
if (obj->kern_version == 0) {
@@ -1072,6 +1099,8 @@ int bpf_object__load(struct bpf_object *obj)
goto out;
if (bpf_object__load_progs(obj))
goto out;
+ if (bpf_object__maps_event_enable(obj))
+ goto out;

return 0;
out:
@@ -1087,6 +1116,7 @@ void bpf_object__close(struct bpf_object *obj)
if (!obj)
return;

+ bpf_object__maps_event_close(obj);
bpf_object__elf_finish(obj);
bpf_object__unload(obj);

--
1.8.3.4


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