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Commit 41e9a804 authored by Teng Qin's avatar Teng Qin Committed by David S. Miller
Browse files

samples/bpf: add tests for more perf event types 



$ 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: default avatarTeng Qin <qinteng@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f91840a3

samples/bpf/bpf_helpers.h

+2 −1
Original line number Diff line number Diff line
@@ -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;

samples/bpf/trace_event_user.c

+63 −10
Original line number Diff line number Diff line
@@ -75,6 +75,9 @@ static void print_stack(struct key_t *key, __u64 count) 
		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)

			print_addr(ip[i]);

	}

	if (count < 6)

		printf("\r");

	else

		printf("\n");



	if (key->kernstack == -EEXIST && !warned) {
@@ -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;

}

samples/bpf/tracex6_kern.c

+21 −7
Original line number Diff line number Diff line
@@ -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 >= -22)

		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;

}

samples/bpf/tracex6_user.c

+142 −38
Original line number Diff line number Diff line 
#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;

}