There is no functionality change in this patch. The common-purpose
perf_event functions are moved from trace_output_user.c to bpf_load.c
so that these function can be reused later.
Signed-off-by: Yonghong Song <y...@fb.com>
---
samples/bpf/bpf_load.c | 104 ++++++++++++++++++++++++++++++++++++
samples/bpf/bpf_load.h | 5 ++
samples/bpf/trace_output_user.c | 113 ++++------------------------------------
3 files changed, 118 insertions(+), 104 deletions(-)
diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index bebe418..62aa5cc 100644
--- a/samples/bpf/bpf_load.c
+++ b/samples/bpf/bpf_load.c
@@ -713,3 +713,107 @@ struct ksym *ksym_search(long key)
return &syms[0];
}
+static int page_size;
+static int page_cnt = 8;
+static volatile struct perf_event_mmap_page *header;
+
+static int perf_event_mmap(int fd)
+{
+ void *base;
+ int mmap_size;
+
+ page_size = getpagesize();
+ mmap_size = page_size * (page_cnt + 1);
+
+ base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ if (base == MAP_FAILED) {
+ printf("mmap err\n");
+ return -1;
+ }
+
+ header = base;
+ return 0;
+}
+
+static int perf_event_poll(int fd)
+{
+ struct pollfd pfd = { .fd = fd, .events = POLLIN };
+
+ return poll(&pfd, 1, 1000);
+}
+
+struct perf_event_sample {
+ struct perf_event_header header;
+ __u32 size;
+ char data[];
+};
+
+static void perf_event_read(perf_event_print_fn fn)
+{
+ __u64 data_tail = header->data_tail;
+ __u64 data_head = header->data_head;
+ __u64 buffer_size = page_cnt * page_size;
+ void *base, *begin, *end;
+ char buf[256];
+
+ asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */
+ if (data_head == data_tail)
+ return;
+
+ base = ((char *)header) + page_size;
+
+ begin = base + data_tail % buffer_size;
+ end = base + data_head % buffer_size;
+
+ while (begin != end) {
+ struct perf_event_sample *e;
+
+ e = begin;
+ if (begin + e->header.size > base + buffer_size) {
+ long len = base + buffer_size - begin;
+
+ assert(len < e->header.size);
+ memcpy(buf, begin, len);
+ memcpy(buf + len, base, e->header.size - len);
+ e = (void *) buf;
+ begin = base + e->header.size - len;
+ } else if (begin + e->header.size == base + buffer_size) {
+ begin = base;
+ } else {
+ begin += e->header.size;
+ }
+
+ if (e->header.type == PERF_RECORD_SAMPLE) {
+ fn(e->data, e->size);
+ } else if (e->header.type == PERF_RECORD_LOST) {
+ struct {
+ struct perf_event_header header;
+ __u64 id;
+ __u64 lost;
+ } *lost = (void *) e;
+ printf("lost %lld events\n", lost->lost);
+ } else {
+ printf("unknown event type=%d size=%d\n",
+ e->header.type, e->header.size);
+ }
+ }
+
+ __sync_synchronize(); /* smp_mb() */
+ header->data_tail = data_head;
+}
+
+int perf_event_poller(int fd, perf_event_exec_fn exec_fn,
+ perf_event_print_fn output_fn)
+{
+ if (perf_event_mmap(fd) < 0)
+ return 1;
+
+ exec_fn();
+
+ for (;;) {
+ perf_event_poll(fd);
+ perf_event_read(output_fn);
+ }
+
+ return 0;
+}
diff --git a/samples/bpf/bpf_load.h b/samples/bpf/bpf_load.h
index 453c200..d618750 100644
--- a/samples/bpf/bpf_load.h
+++ b/samples/bpf/bpf_load.h
@@ -62,4 +62,9 @@ struct ksym {
int load_kallsyms(void);
struct ksym *ksym_search(long key);
int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
+
+typedef void (*perf_event_exec_fn)(void);
+typedef void (*perf_event_print_fn)(void *data, int size);
+int perf_event_poller(int fd, perf_event_exec_fn exec_fn,
+ perf_event_print_fn output_fn);
#endif
diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
index ccca1e3..3d3991f 100644
--- a/samples/bpf/trace_output_user.c
+++ b/samples/bpf/trace_output_user.c
@@ -24,97 +24,6 @@
static int pmu_fd;
-int page_size;
-int page_cnt = 8;
-volatile struct perf_event_mmap_page *header;
-
-typedef void (*print_fn)(void *data, int size);
-
-static int perf_event_mmap(int fd)
-{
- void *base;
- int mmap_size;
-
- page_size = getpagesize();
- mmap_size = page_size * (page_cnt + 1);
-
- base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
- if (base == MAP_FAILED) {
- printf("mmap err\n");
- return -1;
- }
-
- header = base;
- return 0;
-}
-
-static int perf_event_poll(int fd)
-{
- struct pollfd pfd = { .fd = fd, .events = POLLIN };
-
- return poll(&pfd, 1, 1000);
-}
-
-struct perf_event_sample {
- struct perf_event_header header;
- __u32 size;
- char data[];
-};
-
-static void perf_event_read(print_fn fn)
-{
- __u64 data_tail = header->data_tail;
- __u64 data_head = header->data_head;
- __u64 buffer_size = page_cnt * page_size;
- void *base, *begin, *end;
- char buf[256];
-
- asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */
- if (data_head == data_tail)
- return;
-
- base = ((char *)header) + page_size;
-
- begin = base + data_tail % buffer_size;
- end = base + data_head % buffer_size;
-
- while (begin != end) {
- struct perf_event_sample *e;
-
- e = begin;
- if (begin + e->header.size > base + buffer_size) {
- long len = base + buffer_size - begin;
-
- assert(len < e->header.size);
- memcpy(buf, begin, len);
- memcpy(buf + len, base, e->header.size - len);
- e = (void *) buf;
- begin = base + e->header.size - len;
- } else if (begin + e->header.size == base + buffer_size) {
- begin = base;
- } else {
- begin += e->header.size;
- }
-
- if (e->header.type == PERF_RECORD_SAMPLE) {
- fn(e->data, e->size);
- } else if (e->header.type == PERF_RECORD_LOST) {
- struct {
- struct perf_event_header header;
- __u64 id;
- __u64 lost;
- } *lost = (void *) e;
- printf("lost %lld events\n", lost->lost);
- } else {
- printf("unknown event type=%d size=%d\n",
- e->header.type, e->header.size);
- }
- }
-
- __sync_synchronize(); /* smp_mb() */
- header->data_tail = data_head;
-}
-
static __u64 time_get_ns(void)
{
struct timespec ts;
@@ -166,10 +75,17 @@ static void test_bpf_perf_event(void)
ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
}
+static void exec_action(void)
+{
+ FILE *f;
+
+ f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
+ (void) f;
+}
+
int main(int argc, char **argv)
{
char filename[256];
- FILE *f;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
@@ -180,17 +96,6 @@ int main(int argc, char **argv)
test_bpf_perf_event();
- if (perf_event_mmap(pmu_fd) < 0)
- return 1;
-
- f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
- (void) f;
-
start_time = time_get_ns();
- for (;;) {
- perf_event_poll(pmu_fd);
- perf_event_read(print_bpf_output);
- }
-
- return 0;
+ return perf_event_poller(pmu_fd, exec_action, print_bpf_output);
}
--
2.9.5
