From: Teng Qin <qint...@fb.com>
$ trace_event
tests attaching BPF program to HW_CPU_CYCLES, SW_CPU_CLOCK, HW_CACHE_L1D and
other events.
It runs 'dd' in the background while bpf program collects user and kernel
stack trace on counter overflow.
User space expects to see sys_read and sys_write in the kernel stack.
$ tracex6
tests reading of various perf counters from BPF program.
Both tests were refactored to increase coverage and be more accurate.
Signed-off-by: Teng Qin <qint...@fb.com>
Signed-off-by: Alexei Starovoitov <a...@kernel.org>
---
samples/bpf/bpf_helpers.h | 3 +-
samples/bpf/trace_event_user.c | 73 ++++++++++++++---
samples/bpf/tracex6_kern.c | 28 +++++--
samples/bpf/tracex6_user.c | 180 ++++++++++++++++++++++++++++++++---------
4 files changed, 228 insertions(+), 56 deletions(-)
diff --git a/samples/bpf/bpf_helpers.h b/samples/bpf/bpf_helpers.h
index 9a9c95f2c9fb..51e567bc70fc 100644
--- a/samples/bpf/bpf_helpers.h
+++ b/samples/bpf/bpf_helpers.h
@@ -31,7 +31,8 @@ static unsigned long long (*bpf_get_current_uid_gid)(void) =
(void *) BPF_FUNC_get_current_uid_gid;
static int (*bpf_get_current_comm)(void *buf, int buf_size) =
(void *) BPF_FUNC_get_current_comm;
-static int (*bpf_perf_event_read)(void *map, int index) =
+static unsigned long long (*bpf_perf_event_read)(void *map,
+ unsigned long long flags) =
(void *) BPF_FUNC_perf_event_read;
static int (*bpf_clone_redirect)(void *ctx, int ifindex, int flags) =
(void *) BPF_FUNC_clone_redirect;
diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c
index fa4336423da5..7bd827b84a67 100644
--- a/samples/bpf/trace_event_user.c
+++ b/samples/bpf/trace_event_user.c
@@ -75,7 +75,10 @@ static void print_stack(struct key_t *key, __u64 count)
for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
print_addr(ip[i]);
}
- printf("\n");
+ if (count < 6)
+ printf("\r");
+ else
+ printf("\n");
if (key->kernstack == -EEXIST && !warned) {
printf("stackmap collisions seen. Consider increasing size\n");
@@ -105,7 +108,7 @@ static void print_stacks(void)
bpf_map_delete_elem(fd, &next_key);
key = next_key;
}
-
+ printf("\n");
if (!sys_read_seen || !sys_write_seen) {
printf("BUG kernel stack doesn't contain sys_read() and
sys_write()\n");
int_exit(0);
@@ -122,24 +125,29 @@ static void test_perf_event_all_cpu(struct
perf_event_attr *attr)
{
int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
int *pmu_fd = malloc(nr_cpus * sizeof(int));
- int i;
+ int i, error = 0;
/* open perf_event on all cpus */
for (i = 0; i < nr_cpus; i++) {
pmu_fd[i] = sys_perf_event_open(attr, -1, i, -1, 0);
if (pmu_fd[i] < 0) {
printf("sys_perf_event_open failed\n");
+ error = 1;
goto all_cpu_err;
}
assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) ==
0);
- assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0) == 0);
+ assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE) == 0);
}
- system("dd if=/dev/zero of=/dev/null count=5000k");
+ system("dd if=/dev/zero of=/dev/null count=5000k status=none");
print_stacks();
all_cpu_err:
- for (i--; i >= 0; i--)
+ for (i--; i >= 0; i--) {
+ ioctl(pmu_fd[i], PERF_EVENT_IOC_DISABLE);
close(pmu_fd[i]);
+ }
free(pmu_fd);
+ if (error)
+ int_exit(0);
}
static void test_perf_event_task(struct perf_event_attr *attr)
@@ -150,12 +158,13 @@ static void test_perf_event_task(struct perf_event_attr
*attr)
pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);
if (pmu_fd < 0) {
printf("sys_perf_event_open failed\n");
- return;
+ int_exit(0);
}
assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
- assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
- system("dd if=/dev/zero of=/dev/null count=5000k");
+ assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE) == 0);
+ system("dd if=/dev/zero of=/dev/null count=5000k status=none");
print_stacks();
+ ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
close(pmu_fd);
}
@@ -175,11 +184,56 @@ static void test_bpf_perf_event(void)
.config = PERF_COUNT_SW_CPU_CLOCK,
.inherit = 1,
};
+ struct perf_event_attr attr_hw_cache_l1d = {
+ .sample_freq = SAMPLE_FREQ,
+ .freq = 1,
+ .type = PERF_TYPE_HW_CACHE,
+ .config =
+ PERF_COUNT_HW_CACHE_L1D |
+ (PERF_COUNT_HW_CACHE_OP_READ << 8) |
+ (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
+ .inherit = 1,
+ };
+ struct perf_event_attr attr_hw_cache_branch_miss = {
+ .sample_freq = SAMPLE_FREQ,
+ .freq = 1,
+ .type = PERF_TYPE_HW_CACHE,
+ .config =
+ PERF_COUNT_HW_CACHE_BPU |
+ (PERF_COUNT_HW_CACHE_OP_READ << 8) |
+ (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
+ .inherit = 1,
+ };
+ struct perf_event_attr attr_type_raw = {
+ .sample_freq = SAMPLE_FREQ,
+ .freq = 1,
+ .type = PERF_TYPE_RAW,
+ /* Intel Instruction Retired */
+ .config = 0xc0,
+ .inherit = 1,
+ };
+ printf("Test HW_CPU_CYCLES\n");
test_perf_event_all_cpu(&attr_type_hw);
test_perf_event_task(&attr_type_hw);
+
+ printf("Test SW_CPU_CLOCK\n");
test_perf_event_all_cpu(&attr_type_sw);
test_perf_event_task(&attr_type_sw);
+
+ printf("Test HW_CACHE_L1D\n");
+ test_perf_event_all_cpu(&attr_hw_cache_l1d);
+ test_perf_event_task(&attr_hw_cache_l1d);
+
+ printf("Test HW_CACHE_BPU\n");
+ test_perf_event_all_cpu(&attr_hw_cache_branch_miss);
+ test_perf_event_task(&attr_hw_cache_branch_miss);
+
+ printf("Test Instruction Retired\n");
+ test_perf_event_all_cpu(&attr_type_raw);
+ test_perf_event_task(&attr_type_raw);
+
+ printf("*** PASS ***\n");
}
@@ -209,7 +263,6 @@ int main(int argc, char **argv)
return 0;
}
test_bpf_perf_event();
-
int_exit(0);
return 0;
}
diff --git a/samples/bpf/tracex6_kern.c b/samples/bpf/tracex6_kern.c
index be479c4af9e2..8a7d0f977625 100644
--- a/samples/bpf/tracex6_kern.c
+++ b/samples/bpf/tracex6_kern.c
@@ -3,22 +3,36 @@
#include <uapi/linux/bpf.h>
#include "bpf_helpers.h"
-struct bpf_map_def SEC("maps") my_map = {
+struct bpf_map_def SEC("maps") counters = {
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(u32),
- .max_entries = 32,
+ .max_entries = 64,
+};
+struct bpf_map_def SEC("maps") values = {
+ .type = BPF_MAP_TYPE_HASH,
+ .key_size = sizeof(int),
+ .value_size = sizeof(u64),
+ .max_entries = 64,
};
-SEC("kprobe/sys_write")
+SEC("kprobe/htab_map_get_next_key")
int bpf_prog1(struct pt_regs *ctx)
{
- u64 count;
u32 key = bpf_get_smp_processor_id();
- char fmt[] = "CPU-%d %llu\n";
+ u64 count, *val;
+ s64 error;
+
+ count = bpf_perf_event_read(&counters, key);
+ error = (s64)count;
+ if (error <= -2 && error >= -95)
+ return 0;
- count = bpf_perf_event_read(&my_map, key);
- bpf_trace_printk(fmt, sizeof(fmt), key, count);
+ val = bpf_map_lookup_elem(&values, &key);
+ if (val)
+ *val = count;
+ else
+ bpf_map_update_elem(&values, &key, &count, BPF_NOEXIST);
return 0;
}
diff --git a/samples/bpf/tracex6_user.c b/samples/bpf/tracex6_user.c
index ca7874ed77f4..a05a99a0752f 100644
--- a/samples/bpf/tracex6_user.c
+++ b/samples/bpf/tracex6_user.c
@@ -1,73 +1,177 @@
-#include <stdio.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <stdbool.h>
-#include <string.h>
+#define _GNU_SOURCE
+
+#include <assert.h>
#include <fcntl.h>
-#include <poll.h>
-#include <sys/ioctl.h>
#include <linux/perf_event.h>
#include <linux/bpf.h>
-#include "libbpf.h"
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
#include "bpf_load.h"
+#include "libbpf.h"
#include "perf-sys.h"
#define SAMPLE_PERIOD 0x7fffffffffffffffULL
-static void test_bpf_perf_event(void)
+static void check_on_cpu(int cpu, struct perf_event_attr *attr)
{
- int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
- int *pmu_fd = malloc(nr_cpus * sizeof(int));
- int status, i;
+ int pmu_fd, error = 0;
+ cpu_set_t set;
+ __u64 value;
- struct perf_event_attr attr_insn_pmu = {
+ /* Move to target CPU */
+ CPU_ZERO(&set);
+ CPU_SET(cpu, &set);
+ assert(sched_setaffinity(0, sizeof(set), &set) == 0);
+ /* Open perf event and attach to the perf_event_array */
+ pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/,
-1/*group_fd*/, 0);
+ if (pmu_fd < 0) {
+ fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
+ error = 1;
+ goto on_exit;
+ }
+ assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
+ assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
+ /* Trigger the kprobe */
+ bpf_map_get_next_key(map_fd[1], &cpu, NULL);
+ /* Check the value */
+ if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
+ fprintf(stderr, "Value missing for CPU %d\n", cpu);
+ error = 1;
+ goto on_exit;
+ }
+ fprintf(stderr, "CPU %d: %llu\n", cpu, value);
+
+on_exit:
+ assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
+ assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
+ assert(close(pmu_fd) == 0 || error);
+ assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
+ exit(error);
+}
+
+static void test_perf_event_array(struct perf_event_attr *attr,
+ const char *name)
+{
+ int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+ pid_t pid[nr_cpus];
+ int err = 0;
+
+ printf("Test reading %s counters\n", name);
+
+ for (i = 0; i < nr_cpus; i++) {
+ pid[i] = fork();
+ assert(pid[i] >= 0);
+ if (pid[i] == 0) {
+ check_on_cpu(i, attr);
+ exit(1);
+ }
+ }
+
+ for (i = 0; i < nr_cpus; i++) {
+ assert(waitpid(pid[i], &status, 0) == pid[i]);
+ err |= status;
+ }
+
+ if (err)
+ printf("Test: %s FAILED\n", name);
+}
+
+static void test_bpf_perf_event(void)
+{
+ struct perf_event_attr attr_cycles = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_HARDWARE,
.read_format = 0,
.sample_type = 0,
- .config = 0,/* PMU: cycles */
+ .config = PERF_COUNT_HW_CPU_CYCLES,
+ };
+ struct perf_event_attr attr_clock = {
+ .freq = 0,
+ .sample_period = SAMPLE_PERIOD,
+ .inherit = 0,
+ .type = PERF_TYPE_SOFTWARE,
+ .read_format = 0,
+ .sample_type = 0,
+ .config = PERF_COUNT_SW_CPU_CLOCK,
+ };
+ struct perf_event_attr attr_raw = {
+ .freq = 0,
+ .sample_period = SAMPLE_PERIOD,
+ .inherit = 0,
+ .type = PERF_TYPE_RAW,
+ .read_format = 0,
+ .sample_type = 0,
+ /* Intel Instruction Retired */
+ .config = 0xc0,
+ };
+ struct perf_event_attr attr_l1d_load = {
+ .freq = 0,
+ .sample_period = SAMPLE_PERIOD,
+ .inherit = 0,
+ .type = PERF_TYPE_HW_CACHE,
+ .read_format = 0,
+ .sample_type = 0,
+ .config =
+ PERF_COUNT_HW_CACHE_L1D |
+ (PERF_COUNT_HW_CACHE_OP_READ << 8) |
+ (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
+ };
+ struct perf_event_attr attr_llc_miss = {
+ .freq = 0,
+ .sample_period = SAMPLE_PERIOD,
+ .inherit = 0,
+ .type = PERF_TYPE_HW_CACHE,
+ .read_format = 0,
+ .sample_type = 0,
+ .config =
+ PERF_COUNT_HW_CACHE_LL |
+ (PERF_COUNT_HW_CACHE_OP_READ << 8) |
+ (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
+ };
+ struct perf_event_attr attr_msr_tsc = {
+ .freq = 0,
+ .sample_period = 0,
+ .inherit = 0,
+ /* From /sys/bus/event_source/devices/msr/ */
+ .type = 7,
+ .read_format = 0,
+ .sample_type = 0,
+ .config = 0,
};
- for (i = 0; i < nr_cpus; i++) {
- pmu_fd[i] = sys_perf_event_open(&attr_insn_pmu, -1/*pid*/,
i/*cpu*/, -1/*group_fd*/, 0);
- if (pmu_fd[i] < 0) {
- printf("event syscall failed\n");
- goto exit;
- }
-
- bpf_map_update_elem(map_fd[0], &i, &pmu_fd[i], BPF_ANY);
- ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0);
- }
+ test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
+ test_perf_event_array(&attr_clock, "SOFTWARE-clock");
+ test_perf_event_array(&attr_raw, "RAW-instruction-retired");
+ test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
- status = system("ls > /dev/null");
- if (status)
- goto exit;
- status = system("sleep 2");
- if (status)
- goto exit;
-
-exit:
- for (i = 0; i < nr_cpus; i++)
- close(pmu_fd[i]);
- close(map_fd[0]);
- free(pmu_fd);
+ /* below tests may fail in qemu */
+ test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
+ test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
}
int main(int argc, char **argv)
{
+ struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
char filename[256];
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+ setrlimit(RLIMIT_MEMLOCK, &r);
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
}
test_bpf_perf_event();
- read_trace_pipe();
-
return 0;
}
--
2.9.3
