forked from mirrors/linux
		
	tools/bpftool: switch map event_pipe to libbpf's perf_buffer
Switch event_pipe implementation to rely on new libbpf perf buffer API (it's raw low-level variant). Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
		
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						commit
						9b190f185d
					
				
					 1 changed files with 64 additions and 137 deletions
				
			
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			@ -28,7 +28,7 @@
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#define MMAP_PAGE_CNT	16
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static bool stop;
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static volatile bool stop;
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struct event_ring_info {
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	int fd;
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			@ -44,32 +44,44 @@ struct perf_event_sample {
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	unsigned char data[];
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};
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struct perf_event_lost {
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	struct perf_event_header header;
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	__u64 id;
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	__u64 lost;
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};
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static void int_exit(int signo)
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{
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	fprintf(stderr, "Stopping...\n");
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	stop = true;
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}
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struct event_pipe_ctx {
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	bool all_cpus;
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	int cpu;
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	int idx;
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};
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static enum bpf_perf_event_ret
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print_bpf_output(struct perf_event_header *event, void *private_data)
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print_bpf_output(void *private_data, int cpu, struct perf_event_header *event)
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{
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	struct perf_event_sample *e = container_of(event, struct perf_event_sample,
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	struct perf_event_sample *e = container_of(event,
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						   struct perf_event_sample,
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						   header);
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	struct event_ring_info *ring = private_data;
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	struct {
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		struct perf_event_header header;
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		__u64 id;
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		__u64 lost;
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	} *lost = (typeof(lost))event;
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	struct perf_event_lost *lost = container_of(event,
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						    struct perf_event_lost,
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						    header);
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	struct event_pipe_ctx *ctx = private_data;
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	int idx = ctx->all_cpus ? cpu : ctx->idx;
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	if (json_output) {
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		jsonw_start_object(json_wtr);
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		jsonw_name(json_wtr, "type");
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		jsonw_uint(json_wtr, e->header.type);
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		jsonw_name(json_wtr, "cpu");
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		jsonw_uint(json_wtr, ring->cpu);
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		jsonw_uint(json_wtr, cpu);
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		jsonw_name(json_wtr, "index");
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		jsonw_uint(json_wtr, ring->key);
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		jsonw_uint(json_wtr, idx);
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		if (e->header.type == PERF_RECORD_SAMPLE) {
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			jsonw_name(json_wtr, "timestamp");
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			jsonw_uint(json_wtr, e->time);
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			@ -89,7 +101,7 @@ print_bpf_output(struct perf_event_header *event, void *private_data)
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		if (e->header.type == PERF_RECORD_SAMPLE) {
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			printf("== @%lld.%09lld CPU: %d index: %d =====\n",
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			       e->time / 1000000000ULL, e->time % 1000000000ULL,
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			       ring->cpu, ring->key);
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			       cpu, idx);
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			fprint_hex(stdout, e->data, e->size, " ");
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			printf("\n");
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		} else if (e->header.type == PERF_RECORD_LOST) {
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			@ -103,87 +115,25 @@ print_bpf_output(struct perf_event_header *event, void *private_data)
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	return LIBBPF_PERF_EVENT_CONT;
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}
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static void
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perf_event_read(struct event_ring_info *ring, void **buf, size_t *buf_len)
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int do_event_pipe(int argc, char **argv)
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{
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	enum bpf_perf_event_ret ret;
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	ret = bpf_perf_event_read_simple(ring->mem,
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					 MMAP_PAGE_CNT * get_page_size(),
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					 get_page_size(), buf, buf_len,
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					 print_bpf_output, ring);
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	if (ret != LIBBPF_PERF_EVENT_CONT) {
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		fprintf(stderr, "perf read loop failed with %d\n", ret);
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		stop = true;
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	}
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}
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static int perf_mmap_size(void)
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{
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	return get_page_size() * (MMAP_PAGE_CNT + 1);
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}
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static void *perf_event_mmap(int fd)
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{
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	int mmap_size = perf_mmap_size();
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	void *base;
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	base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
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	if (base == MAP_FAILED) {
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		p_err("event mmap failed: %s\n", strerror(errno));
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		return NULL;
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	}
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	return base;
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}
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static void perf_event_unmap(void *mem)
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{
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	if (munmap(mem, perf_mmap_size()))
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		fprintf(stderr, "Can't unmap ring memory!\n");
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}
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static int bpf_perf_event_open(int map_fd, int key, int cpu)
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{
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	struct perf_event_attr attr = {
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	struct perf_event_attr perf_attr = {
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		.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_TIME,
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		.type = PERF_TYPE_SOFTWARE,
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		.config = PERF_COUNT_SW_BPF_OUTPUT,
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		.sample_period = 1,
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		.wakeup_events = 1,
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	};
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	int pmu_fd;
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	pmu_fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
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	if (pmu_fd < 0) {
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		p_err("failed to open perf event %d for CPU %d", key, cpu);
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		return -1;
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	}
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	if (bpf_map_update_elem(map_fd, &key, &pmu_fd, BPF_ANY)) {
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		p_err("failed to update map for event %d for CPU %d", key, cpu);
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		goto err_close;
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	}
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	if (ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0)) {
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		p_err("failed to enable event %d for CPU %d", key, cpu);
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		goto err_close;
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	}
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	return pmu_fd;
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err_close:
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	close(pmu_fd);
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	return -1;
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}
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int do_event_pipe(int argc, char **argv)
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{
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	int i, nfds, map_fd, index = -1, cpu = -1;
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	struct bpf_map_info map_info = {};
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	struct event_ring_info *rings;
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	size_t tmp_buf_sz = 0;
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	void *tmp_buf = NULL;
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	struct pollfd *pfds;
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	struct perf_buffer_raw_opts opts = {};
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	struct event_pipe_ctx ctx = {
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		.all_cpus = true,
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		.cpu = -1,
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		.idx = -1,
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	};
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	struct perf_buffer *pb;
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	__u32 map_info_len;
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	bool do_all = true;
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	int err, map_fd;
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	map_info_len = sizeof(map_info);
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	map_fd = map_parse_fd_and_info(&argc, &argv, &map_info, &map_info_len);
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			@ -205,7 +155,7 @@ int do_event_pipe(int argc, char **argv)
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			char *endptr;
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			NEXT_ARG();
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			cpu = strtoul(*argv, &endptr, 0);
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			ctx.cpu = strtoul(*argv, &endptr, 0);
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			if (*endptr) {
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				p_err("can't parse %s as CPU ID", **argv);
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				goto err_close_map;
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			@ -216,7 +166,7 @@ int do_event_pipe(int argc, char **argv)
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			char *endptr;
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			NEXT_ARG();
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			index = strtoul(*argv, &endptr, 0);
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			ctx.idx = strtoul(*argv, &endptr, 0);
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			if (*endptr) {
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				p_err("can't parse %s as index", **argv);
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				goto err_close_map;
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			@ -228,45 +178,32 @@ int do_event_pipe(int argc, char **argv)
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			goto err_close_map;
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		}
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		do_all = false;
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		ctx.all_cpus = false;
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	}
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	if (!do_all) {
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		if (index == -1 || cpu == -1) {
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	if (!ctx.all_cpus) {
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		if (ctx.idx == -1 || ctx.cpu == -1) {
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			p_err("cpu and index must be specified together");
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			goto err_close_map;
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		}
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		nfds = 1;
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	} else {
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		nfds = min(get_possible_cpus(), map_info.max_entries);
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		cpu = 0;
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		index = 0;
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		ctx.cpu = 0;
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		ctx.idx = 0;
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	}
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	rings = calloc(nfds, sizeof(rings[0]));
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	if (!rings)
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	opts.attr = &perf_attr;
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	opts.event_cb = print_bpf_output;
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	opts.ctx = &ctx;
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	opts.cpu_cnt = ctx.all_cpus ? 0 : 1;
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	opts.cpus = &ctx.cpu;
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	opts.map_keys = &ctx.idx;
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	pb = perf_buffer__new_raw(map_fd, MMAP_PAGE_CNT, &opts);
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	err = libbpf_get_error(pb);
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	if (err) {
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		p_err("failed to create perf buffer: %s (%d)",
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		      strerror(err), err);
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		goto err_close_map;
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	pfds = calloc(nfds, sizeof(pfds[0]));
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	if (!pfds)
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		goto err_free_rings;
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	for (i = 0; i < nfds; i++) {
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		rings[i].cpu = cpu + i;
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		rings[i].key = index + i;
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		rings[i].fd = bpf_perf_event_open(map_fd, rings[i].key,
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						  rings[i].cpu);
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		if (rings[i].fd < 0)
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			goto err_close_fds_prev;
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		rings[i].mem = perf_event_mmap(rings[i].fd);
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		if (!rings[i].mem)
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			goto err_close_fds_current;
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		pfds[i].fd = rings[i].fd;
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		pfds[i].events = POLLIN;
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	}
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	signal(SIGINT, int_exit);
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			@ -277,34 +214,24 @@ int do_event_pipe(int argc, char **argv)
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		jsonw_start_array(json_wtr);
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	while (!stop) {
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		poll(pfds, nfds, 200);
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		for (i = 0; i < nfds; i++)
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			perf_event_read(&rings[i], &tmp_buf, &tmp_buf_sz);
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		err = perf_buffer__poll(pb, 200);
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		if (err < 0 && err != -EINTR) {
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			p_err("perf buffer polling failed: %s (%d)",
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			      strerror(err), err);
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			goto err_close_pb;
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		}
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	}
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	free(tmp_buf);
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	if (json_output)
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		jsonw_end_array(json_wtr);
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	for (i = 0; i < nfds; i++) {
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		perf_event_unmap(rings[i].mem);
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		close(rings[i].fd);
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	}
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	free(pfds);
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	free(rings);
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	perf_buffer__free(pb);
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	close(map_fd);
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	return 0;
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err_close_fds_prev:
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	while (i--) {
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		perf_event_unmap(rings[i].mem);
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err_close_fds_current:
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		close(rings[i].fd);
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	}
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	free(pfds);
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err_free_rings:
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	free(rings);
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err_close_pb:
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	perf_buffer__free(pb);
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err_close_map:
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	close(map_fd);
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	return -1;
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