Re: [PATCH v2 bpf-next 8/9] selftests/bpf: add batch ops testing for hmap and hmap_percpu

[Yonghong Song <yhs@fb.com>]

On 11/19/19 11:30 AM, Brian Vazquez wrote:
> From: Yonghong Song <yhs@fb.com>
> 
> Tested bpf_map_lookup_and_delete_batch() and bpf_map_update_batch()
> functionality.
>    $ ./test_maps
>      ...
>        test_hmap_lookup_and_delete_batch:PASS
>        test_pcpu_hmap_lookup_and_delete_batch:PASS
>      ...

Maybe you can add another tests for lookup_batch() and delete_batch()
so all new APIs get tested?

> 
> Signed-off-by: Yonghong Song <yhs@fb.com>
> Signed-off-by: Brian Vazquez <brianvv@google.com>
> ---
>   .../map_lookup_and_delete_batch_htab.c        | 257 ++++++++++++++++++
>   1 file changed, 257 insertions(+)
>   create mode 100644 tools/testing/selftests/bpf/map_tests/map_lookup_and_delete_batch_htab.c
> 
> diff --git a/tools/testing/selftests/bpf/map_tests/map_lookup_and_delete_batch_htab.c b/tools/testing/selftests/bpf/map_tests/map_lookup_and_delete_batch_htab.c
> new file mode 100644
> index 0000000000000..93e024cb85c60
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/map_tests/map_lookup_and_delete_batch_htab.c
> @@ -0,0 +1,257 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2019 Facebook  */
> +#include <stdio.h>
> +#include <errno.h>
> +#include <string.h>
> +
> +#include <bpf/bpf.h>
> +#include <bpf/libbpf.h>
> +
> +#include <bpf_util.h>
> +#include <test_maps.h>
> +
> +static void map_batch_update(int map_fd, __u32 max_entries, int *keys,
> +			     void *values, bool is_pcpu)
> +{
> +	typedef BPF_DECLARE_PERCPU(int, value);
> +	int i, j, err;
> +	value *v;
> +
> +	if (is_pcpu)
> +		v = (value *)values;
> +
> +	for (i = 0; i < max_entries; i++) {
> +		keys[i] = i + 1;
> +		if (is_pcpu)
> +			for (j = 0; j < bpf_num_possible_cpus(); j++)
> +				bpf_percpu(v[i], j) = i + 2 + j;
> +		else
> +			((int *)values)[i] = i + 2;
> +	}
> +
> +	err = bpf_map_update_batch(map_fd, keys, values, &max_entries, 0, 0);
> +	CHECK(err, "bpf_map_update_batch()", "error:%s\n", strerror(errno));
> +}
> +
> +static void map_batch_verify(int *visited, __u32 max_entries,
> +			     int *keys, void *values, bool is_pcpu)
> +{
> +	typedef BPF_DECLARE_PERCPU(int, value);
> +	value *v;
> +	int i, j;
> +
> +	if (is_pcpu)
> +		v = (value *)values;
> +
> +	memset(visited, 0, max_entries * sizeof(*visited));
> +	for (i = 0; i < max_entries; i++) {
> +
> +		if (is_pcpu) {
> +			for (j = 0; j < bpf_num_possible_cpus(); j++) {
> +				CHECK(keys[i] + 1 + j != bpf_percpu(v[i], j),
> +				      "key/value checking",
> +				      "error: i %d j %d key %d value %d\n",
> +				      i, j, keys[i], bpf_percpu(v[i],  j));
> +			}
> +		} else {
> +			CHECK(keys[i] + 1 != ((int *)values)[i],
> +			      "key/value checking",
> +			      "error: i %d key %d value %d\n", i, keys[i],
> +			      ((int *)values)[i]);
> +		}
> +
> +		visited[i] = 1;
> +
> +	}
> +	for (i = 0; i < max_entries; i++) {
> +		CHECK(visited[i] != 1, "visited checking",
> +		      "error: keys array at index %d missing\n", i);
> +	}
> +}
> +
> +void __test_map_lookup_and_delete_batch(bool is_pcpu)
> +{
> +	int map_type = is_pcpu ? BPF_MAP_TYPE_PERCPU_HASH : BPF_MAP_TYPE_HASH;
> +	struct bpf_create_map_attr xattr = {
> +		.name = "hash_map",
> +		.map_type = map_type,
> +		.key_size = sizeof(int),
> +		.value_size = sizeof(int),
> +	};
> +	typedef BPF_DECLARE_PERCPU(int, value);
> +	int map_fd, *keys, *visited, key;
> +	__u32 batch = 0, count, total, total_success;
> +	const __u32 max_entries = 10;
> +	int err, i, step, value_size;
> +	value pcpu_values[10];
> +	bool nospace_err;
> +	void *values;
> +
> +	xattr.max_entries = max_entries;
> +	map_fd = bpf_create_map_xattr(&xattr);
> +	CHECK(map_fd == -1,
> +	      "bpf_create_map_xattr()", "error:%s\n", strerror(errno));
> +
> +	value_size = is_pcpu ? sizeof(value) : sizeof(int);
> +	keys = malloc(max_entries * sizeof(int));
> +	if (is_pcpu)
> +		values = pcpu_values;
> +	else
> +		values = malloc(max_entries * sizeof(int));
> +	visited = malloc(max_entries * sizeof(int));
> +	CHECK(!keys || !values || !visited, "malloc()",
> +	      "error:%s\n", strerror(errno));
> +
> +	/* test 1: lookup/delete an empty hash table, -ENOENT */
> +	count = max_entries;
> +	err = bpf_map_lookup_and_delete_batch(map_fd, NULL, &batch, keys,
> +					      values, &count, 0, 0);
> +	CHECK((err && errno != ENOENT), "empty map",
> +	      "error: %s\n", strerror(errno));
> +
> +	/* populate elements to the map */
> +	map_batch_update(map_fd, max_entries, keys, values, is_pcpu);
> +
> +	/* test 2: lookup/delete with count = 0, success */
> +	batch = 0;
> +	count = 0;
> +	err = bpf_map_lookup_and_delete_batch(map_fd, NULL, &batch, keys,
> +					      values, &count, 0, 0);
> +	CHECK(err, "count = 0", "error: %s\n", strerror(errno));
> +
> +	/* test 3: lookup/delete with count = max_entries, success */
> +	memset(keys, 0, max_entries * sizeof(*keys));
> +	memset(values, 0, max_entries * value_size);
> +	count = max_entries;
> +	batch = 0;
> +	err = bpf_map_lookup_and_delete_batch(map_fd, NULL, &batch, keys,
> +					      values, &count, 0, 0);
> +	CHECK((err && errno != ENOENT), "count = max_entries",
> +	       "error: %s\n", strerror(errno));
> +	CHECK(count != max_entries, "count = max_entries",
> +	      "count = %u, max_entries = %u\n", count, max_entries);
> +	map_batch_verify(visited, max_entries, keys, values, is_pcpu);
> +
> +	/* bpf_map_get_next_key() should return -ENOENT for an empty map. */
> +	err = bpf_map_get_next_key(map_fd, NULL, &key);
> +	CHECK(!err, "bpf_map_get_next_key()", "error: %s\n", strerror(errno));
> +
> +	/* test 4: lookup/delete in a loop with various steps. */
> +	total_success = 0;
> +	for (step = 1; step < max_entries; step++) {
> +		map_batch_update(map_fd, max_entries, keys, values, is_pcpu);
> +		memset(keys, 0, max_entries * sizeof(*keys));
> +		memset(values, 0, max_entries * value_size);
> +		batch = 0;
> +		total = 0;
> +		i = 0;
> +		/* iteratively lookup/delete elements with 'step'
> +		 * elements each
> +		 */
> +		count = step;
> +		nospace_err = false;
> +		while (true) {
> +			err = bpf_map_lookup_batch(map_fd,
> +						   total ? &batch : NULL,
> +						   &batch, keys + total,
> +						   values +
> +						   total * value_size,
> +						   &count, 0, 0);
> +			/* It is possible that we are failing due to buffer size
> +			 * not big enough. In such cases, let us just exit and
> +			 * go with large steps. Not that a buffer size with
> +			 * max_entries should always work.
> +			 */
> +			if (err && errno == ENOSPC) {
> +				nospace_err = true;
> +				break;
> +			}
> +
> +
> +			CHECK((err && errno != ENOENT), "lookup with steps",
> +			      "error: %s\n", strerror(errno));
> +
> +			total += count;
> +			if (err)
> +				break;
> +
> +			i++;
> +		}
> +		if (nospace_err == true)
> +			continue;
> +
> +		CHECK(total != max_entries, "lookup with steps",
> +		      "total = %u, max_entries = %u\n", total, max_entries);
> +		map_batch_verify(visited, max_entries, keys, values, is_pcpu);
> +
> +		memset(keys, 0, max_entries * sizeof(*keys));
> +		memset(values, 0, max_entries * value_size);
> +		batch = 0;
> +		total = 0;
> +		i = 0;
> +		/* iteratively lookup/delete elements with 'step'
> +		 * elements each
> +		 */
> +		count = step;
> +		nospace_err = false;
> +		while (true) {
> +			err = bpf_map_lookup_and_delete_batch(map_fd,
> +							total ? &batch : NULL,
> +							&batch, keys + total,
> +							values +
> +							total * value_size,
> +							&count, 0, 0);
> +			/* It is possible that we are failing due to buffer size
> +			 * not big enough. In such cases, let us just exit and
> +			 * go with large steps. Not that a buffer size with
> +			 * max_entries should always work.
> +			 */
> +			if (err && errno == ENOSPC) {
> +				nospace_err = true;
> +				break;
> +			}
> +
> +			CHECK((err && errno != ENOENT), "lookup with steps",
> +			      "error: %s\n", strerror(errno));
> +
> +			total += count;
> +			if (err)
> +				break;
> +			i++;
> +		}
> +
> +		if (nospace_err == true)
> +			continue;
> +
> +		CHECK(total != max_entries, "lookup/delete with steps",
> +		      "total = %u, max_entries = %u\n", total, max_entries);
> +
> +		map_batch_verify(visited, max_entries, keys, values, is_pcpu);
> +		err = bpf_map_get_next_key(map_fd, NULL, &key);
> +		CHECK(!err, "bpf_map_get_next_key()", "error: %s\n",
> +		      strerror(errno));
> +
> +		total_success++;
> +	}
> +
> +	CHECK(total_success == 0, "check total_success",
> +	      "unexpected failure\n");
> +}
> +
> +void test_hmap_lookup_and_delete_batch(void)
> +{
> +	__test_map_lookup_and_delete_batch(false);
> +	printf("%s:PASS\n", __func__);
> +}
> +
> +void test_pcpu_hmap_lookup_and_delete_batch(void)
> +{
> +	__test_map_lookup_and_delete_batch(true);
> +	printf("%s:PASS\n", __func__);
> +}
> +
> +void test_map_lookup_and_delete_batch_htab(void)
> +{
> +	test_hmap_lookup_and_delete_batch();
> +	test_pcpu_hmap_lookup_and_delete_batch();
> +}
>