1 files changed, 470 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/map_tests/map_percpu_stats.c b/tools/testing/selftests/bpf/map_tests/map_percpu_stats.c
new file mode 100644
index 000000000000..2ea36408816b
--- /dev/null
+++ b/tools/testing/selftests/bpf/map_tests/map_percpu_stats.c
@@ -0,0 +1,470 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Isovalent */
+
+#include <errno.h>
+#include <unistd.h>
+#include <pthread.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include <bpf_util.h>
+#include <test_maps.h>
+
+#include "map_percpu_stats.skel.h"
+
+#define MAX_ENTRIES			16384
+#define MAX_ENTRIES_HASH_OF_MAPS	64
+#define N_THREADS			8
+#define MAX_MAP_KEY_SIZE		4
+
+static void map_info(int map_fd, struct bpf_map_info *info)
+{
+	__u32 len = sizeof(*info);
+	int ret;
+
+	memset(info, 0, sizeof(*info));
+
+	ret = bpf_obj_get_info_by_fd(map_fd, info, &len);
+	CHECK(ret < 0, "bpf_obj_get_info_by_fd", "error: %s\n", strerror(errno));
+}
+
+static const char *map_type_to_s(__u32 type)
+{
+	switch (type) {
+	case BPF_MAP_TYPE_HASH:
+		return "HASH";
+	case BPF_MAP_TYPE_PERCPU_HASH:
+		return "PERCPU_HASH";
+	case BPF_MAP_TYPE_LRU_HASH:
+		return "LRU_HASH";
+	case BPF_MAP_TYPE_LRU_PERCPU_HASH:
+		return "LRU_PERCPU_HASH";
+	case BPF_MAP_TYPE_HASH_OF_MAPS:
+		return "BPF_MAP_TYPE_HASH_OF_MAPS";
+	default:
+		return "<define-me>";
+	}
+}
+
+static __u32 map_count_elements(__u32 type, int map_fd)
+{
+	__u32 key = -1;
+	int n = 0;
+
+	while (!bpf_map_get_next_key(map_fd, &key, &key))
+		n++;
+	return n;
+}
+
+#define BATCH	true
+
+static void delete_and_lookup_batch(int map_fd, void *keys, __u32 count)
+{
+	static __u8 values[(8 << 10) * MAX_ENTRIES];
+	void *in_batch = NULL, *out_batch;
+	__u32 save_count = count;
+	int ret;
+
+	ret = bpf_map_lookup_and_delete_batch(map_fd,
+					      &in_batch, &out_batch,
+					      keys, values, &count,
+					      NULL);
+
+	/*
+	 * Despite what uapi header says, lookup_and_delete_batch will return
+	 * -ENOENT in case we successfully have deleted all elements, so check
+	 * this separately
+	 */
+	CHECK(ret < 0 && (errno != ENOENT || !count), "bpf_map_lookup_and_delete_batch",
+		       "error: %s\n", strerror(errno));
+
+	CHECK(count != save_count,
+			"bpf_map_lookup_and_delete_batch",
+			"deleted not all elements: removed=%u expected=%u\n",
+			count, save_count);
+}
+
+static void delete_all_elements(__u32 type, int map_fd, bool batch)
+{
+	static __u8 val[8 << 10]; /* enough for 1024 CPUs */
+	__u32 key = -1;
+	void *keys;
+	__u32 i, n;
+	int ret;
+
+	keys = calloc(MAX_MAP_KEY_SIZE, MAX_ENTRIES);
+	CHECK(!keys, "calloc", "error: %s\n", strerror(errno));
+
+	for (n = 0; !bpf_map_get_next_key(map_fd, &key, &key); n++)
+		memcpy(keys + n*MAX_MAP_KEY_SIZE, &key, MAX_MAP_KEY_SIZE);
+
+	if (batch) {
+		/* Can't mix delete_batch and delete_and_lookup_batch because
+		 * they have different semantics in relation to the keys
+		 * argument. However, delete_batch utilize map_delete_elem,
+		 * so we actually test it in non-batch scenario */
+		delete_and_lookup_batch(map_fd, keys, n);
+	} else {
+		/* Intentionally mix delete and lookup_and_delete so we can test both */
+		for (i = 0; i < n; i++) {
+			void *keyp = keys + i*MAX_MAP_KEY_SIZE;
+
+			if (i % 2 || type == BPF_MAP_TYPE_HASH_OF_MAPS) {
+				ret = bpf_map_delete_elem(map_fd, keyp);
+				CHECK(ret < 0, "bpf_map_delete_elem",
+					       "error: key %u: %s\n", i, strerror(errno));
+			} else {
+				ret = bpf_map_lookup_and_delete_elem(map_fd, keyp, val);
+				CHECK(ret < 0, "bpf_map_lookup_and_delete_elem",
+					       "error: key %u: %s\n", i, strerror(errno));
+			}
+		}
+	}
+
+	free(keys);
+}
+
+static bool is_lru(__u32 map_type)
+{
+	return map_type == BPF_MAP_TYPE_LRU_HASH ||
+	       map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
+}
+
+static bool is_percpu(__u32 map_type)
+{
+	return map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+	       map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
+}
+
+struct upsert_opts {
+	__u32 map_type;
+	int map_fd;
+	__u32 n;
+	bool retry_for_nomem;
+};
+
+static int create_small_hash(void)
+{
+	int map_fd;
+
+	map_fd = bpf_map_create(BPF_MAP_TYPE_HASH, "small", 4, 4, 4, NULL);
+	CHECK(map_fd < 0, "bpf_map_create()", "error:%s (name=%s)\n",
+			strerror(errno), "small");
+
+	return map_fd;
+}
+
+static bool retry_for_nomem_fn(int err)
+{
+	return err == ENOMEM;
+}
+
+static void *patch_map_thread(void *arg)
+{
+	/* 8KB is enough for 1024 CPUs. And it is shared between N_THREADS. */
+	static __u8 blob[8 << 10];
+	struct upsert_opts *opts = arg;
+	void *val_ptr;
+	int val;
+	int ret;
+	int i;
+
+	for (i = 0; i < opts->n; i++) {
+		if (opts->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
+			val = create_small_hash();
+			val_ptr = &val;
+		} else if (is_percpu(opts->map_type)) {
+			val_ptr = blob;
+		} else {
+			val = rand();
+			val_ptr = &val;
+		}
+
+		/* 2 seconds may be enough ? */
+		if (opts->retry_for_nomem)
+			ret = map_update_retriable(opts->map_fd, &i, val_ptr, 0,
+						   40, retry_for_nomem_fn);
+		else
+			ret = bpf_map_update_elem(opts->map_fd, &i, val_ptr, 0);
+		CHECK(ret < 0, "bpf_map_update_elem", "key=%d error: %s\n", i, strerror(errno));
+
+		if (opts->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
+			close(val);
+	}
+	return NULL;
+}
+
+static void upsert_elements(struct upsert_opts *opts)
+{
+	pthread_t threads[N_THREADS];
+	int ret;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(threads); i++) {
+		ret = pthread_create(&i[threads], NULL, patch_map_thread, opts);
+		CHECK(ret != 0, "pthread_create", "error: %s\n", strerror(ret));
+	}
+
+	for (i = 0; i < ARRAY_SIZE(threads); i++) {
+		ret = pthread_join(i[threads], NULL);
+		CHECK(ret != 0, "pthread_join", "error: %s\n", strerror(ret));
+	}
+}
+
+static __u32 read_cur_elements(int iter_fd)
+{
+	char buf[64];
+	ssize_t n;
+	__u32 ret;
+
+	n = read(iter_fd, buf, sizeof(buf)-1);
+	CHECK(n <= 0, "read", "error: %s\n", strerror(errno));
+	buf[n] = '\0';
+
+	errno = 0;
+	ret = (__u32)strtol(buf, NULL, 10);
+	CHECK(errno != 0, "strtol", "error: %s\n", strerror(errno));
+
+	return ret;
+}
+
+static __u32 get_cur_elements(int map_id)
+{
+	struct map_percpu_stats *skel;
+	struct bpf_link *link;
+	__u32 n_elements;
+	int iter_fd;
+	int ret;
+
+	skel = map_percpu_stats__open();
+	CHECK(skel == NULL, "map_percpu_stats__open", "error: %s", strerror(errno));
+
+	skel->bss->target_id = map_id;
+
+	ret = map_percpu_stats__load(skel);
+	CHECK(ret != 0, "map_percpu_stats__load", "error: %s", strerror(errno));
+
+	link = bpf_program__attach_iter(skel->progs.dump_bpf_map, NULL);
+	CHECK(!link, "bpf_program__attach_iter", "error: %s\n", strerror(errno));
+
+	iter_fd = bpf_iter_create(bpf_link__fd(link));
+	CHECK(iter_fd < 0, "bpf_iter_create", "error: %s\n", strerror(errno));
+
+	n_elements = read_cur_elements(iter_fd);
+
+	close(iter_fd);
+	bpf_link__destroy(link);
+	map_percpu_stats__destroy(skel);
+
+	return n_elements;
+}
+
+static void check_expected_number_elements(__u32 n_inserted, int map_fd,
+					   struct bpf_map_info *info)
+{
+	__u32 n_real;
+	__u32 n_iter;
+
+	/* Count the current number of elements in the map by iterating through
+	 * all the map keys via bpf_get_next_key
+	 */
+	n_real = map_count_elements(info->type, map_fd);
+
+	/* The "real" number of elements should be the same as the inserted
+	 * number of elements in all cases except LRU maps, where some elements
+	 * may have been evicted
+	 */
+	if (n_inserted == 0 || !is_lru(info->type))
+		CHECK(n_inserted != n_real, "map_count_elements",
+		      "n_real(%u) != n_inserted(%u)\n", n_real, n_inserted);
+
+	/* Count the current number of elements in the map using an iterator */
+	n_iter = get_cur_elements(info->id);
+
+	/* Both counts should be the same, as all updates are over */
+	CHECK(n_iter != n_real, "get_cur_elements",
+	      "n_iter=%u, expected %u (map_type=%s,map_flags=%08x)\n",
+	      n_iter, n_real, map_type_to_s(info->type), info->map_flags);
+}
+
+static void __test(int map_fd)
+{
+	struct upsert_opts opts = {
+		.map_fd = map_fd,
+	};
+	struct bpf_map_info info;
+
+	map_info(map_fd, &info);
+	opts.map_type = info.type;
+	opts.n = info.max_entries;
+
+	/* Reduce the number of elements we are updating such that we don't
+	 * bump into -E2BIG from non-preallocated hash maps, but still will
+	 * have some evictions for LRU maps  */
+	if (opts.map_type != BPF_MAP_TYPE_HASH_OF_MAPS)
+		opts.n -= 512;
+	else
+		opts.n /= 2;
+
+	/* per-cpu bpf memory allocator may not be able to allocate per-cpu
+	 * pointer successfully and it can not refill free llist timely, and
+	 * bpf_map_update_elem() will return -ENOMEM. so just retry to mitigate
+	 * the problem temporarily.
+	 */
+	opts.retry_for_nomem = is_percpu(opts.map_type) && (info.map_flags & BPF_F_NO_PREALLOC);
+
+	/*
+	 * Upsert keys [0, n) under some competition: with random values from
+	 * N_THREADS threads. Check values, then delete all elements and check
+	 * values again.
+	 */
+	upsert_elements(&opts);
+	check_expected_number_elements(opts.n, map_fd, &info);
+	delete_all_elements(info.type, map_fd, !BATCH);
+	check_expected_number_elements(0, map_fd, &info);
+
+	/* Now do the same, but using batch delete operations */
+	upsert_elements(&opts);
+	check_expected_number_elements(opts.n, map_fd, &info);
+	delete_all_elements(info.type, map_fd, BATCH);
+	check_expected_number_elements(0, map_fd, &info);
+
+	close(map_fd);
+}
+
+static int map_create_opts(__u32 type, const char *name,
+			   struct bpf_map_create_opts *map_opts,
+			   __u32 key_size, __u32 val_size)
+{
+	int max_entries;
+	int map_fd;
+
+	if (type == BPF_MAP_TYPE_HASH_OF_MAPS)
+		max_entries = MAX_ENTRIES_HASH_OF_MAPS;
+	else
+		max_entries = MAX_ENTRIES;
+
+	map_fd = bpf_map_create(type, name, key_size, val_size, max_entries, map_opts);
+	CHECK(map_fd < 0, "bpf_map_create()", "error:%s (name=%s)\n",
+			strerror(errno), name);
+
+	return map_fd;
+}
+
+static int map_create(__u32 type, const char *name, struct bpf_map_create_opts *map_opts)
+{
+	return map_create_opts(type, name, map_opts, sizeof(int), sizeof(int));
+}
+
+static int create_hash(void)
+{
+	LIBBPF_OPTS(bpf_map_create_opts, map_opts, .map_flags = BPF_F_NO_PREALLOC);
+
+	return map_create(BPF_MAP_TYPE_HASH, "hash", &map_opts);
+}
+
+static int create_percpu_hash(void)
+{
+	LIBBPF_OPTS(bpf_map_create_opts, map_opts, .map_flags = BPF_F_NO_PREALLOC);
+
+	return map_create(BPF_MAP_TYPE_PERCPU_HASH, "percpu_hash", &map_opts);
+}
+
+static int create_hash_prealloc(void)
+{
+	return map_create(BPF_MAP_TYPE_HASH, "hash", NULL);
+}
+
+static int create_percpu_hash_prealloc(void)
+{
+	return map_create(BPF_MAP_TYPE_PERCPU_HASH, "percpu_hash_prealloc", NULL);
+}
+
+static int create_lru_hash(__u32 type, __u32 map_flags)
+{
+	LIBBPF_OPTS(bpf_map_create_opts, map_opts, .map_flags = map_flags);
+
+	return map_create(type, "lru_hash", &map_opts);
+}
+
+static int create_hash_of_maps(void)
+{
+	LIBBPF_OPTS(bpf_map_create_opts, map_opts,
+		.map_flags = BPF_F_NO_PREALLOC,
+		.inner_map_fd = create_small_hash(),
+	);
+	int ret;
+
+	ret = map_create_opts(BPF_MAP_TYPE_HASH_OF_MAPS, "hash_of_maps",
+			      &map_opts, sizeof(int), sizeof(int));
+	close(map_opts.inner_map_fd);
+	return ret;
+}
+
+static void map_percpu_stats_hash(void)
+{
+	__test(create_hash());
+	printf("test_%s:PASS\n", __func__);
+}
+
+static void map_percpu_stats_percpu_hash(void)
+{
+	__test(create_percpu_hash());
+	printf("test_%s:PASS\n", __func__);
+}
+
+static void map_percpu_stats_hash_prealloc(void)
+{
+	__test(create_hash_prealloc());
+	printf("test_%s:PASS\n", __func__);
+}
+
+static void map_percpu_stats_percpu_hash_prealloc(void)
+{
+	__test(create_percpu_hash_prealloc());
+	printf("test_%s:PASS\n", __func__);
+}
+
+static void map_percpu_stats_lru_hash(void)
+{
+	__test(create_lru_hash(BPF_MAP_TYPE_LRU_HASH, 0));
+	printf("test_%s:PASS\n", __func__);
+}
+
+static void map_percpu_stats_lru_hash_no_common(void)
+{
+	__test(create_lru_hash(BPF_MAP_TYPE_LRU_HASH, BPF_F_NO_COMMON_LRU));
+	printf("test_%s:PASS\n", __func__);
+}
+
+static void map_percpu_stats_percpu_lru_hash(void)
+{
+	__test(create_lru_hash(BPF_MAP_TYPE_LRU_PERCPU_HASH, 0));
+	printf("test_%s:PASS\n", __func__);
+}
+
+static void map_percpu_stats_percpu_lru_hash_no_common(void)
+{
+	__test(create_lru_hash(BPF_MAP_TYPE_LRU_PERCPU_HASH, BPF_F_NO_COMMON_LRU));
+	printf("test_%s:PASS\n", __func__);
+}
+
+static void map_percpu_stats_hash_of_maps(void)
+{
+	__test(create_hash_of_maps());
+	printf("test_%s:PASS\n", __func__);
+}
+
+void test_map_percpu_stats(void)
+{
+	map_percpu_stats_hash();
+	map_percpu_stats_percpu_hash();
+	map_percpu_stats_hash_prealloc();
+	map_percpu_stats_percpu_hash_prealloc();
+	map_percpu_stats_lru_hash();
+	map_percpu_stats_lru_hash_no_common();
+	map_percpu_stats_percpu_lru_hash();
+	map_percpu_stats_percpu_lru_hash_no_common();
+	map_percpu_stats_hash_of_maps();
+}