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

[Brian Vazquez]

On Thu, Nov 21, 2019 at 10:36 AM Yonghong Song <yhs@xxxxxx> wrote:
>
>
>
> On 11/19/19 11:30 AM, Brian Vazquez wrote:
> > From: Yonghong Song <yhs@xxxxxx>
> >
> > 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?

I did test lookup_batch() and the code is there, I will add
delete_batch() testing and change the name of the tests to better
reflect what is being tested.

>
> >
> > Signed-off-by: Yonghong Song <yhs@xxxxxx>
> > Signed-off-by: Brian Vazquez <brianvv@xxxxxxxxxx>
> > ---
> >   .../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();
> > +}
> >