[PATCH bpf-next v4 2/3] bpf: selftests: remove percpu macros from bpf_util.h

From: Pedro Tammela
Date: Thu Apr 15 2021 - 13:47:10 EST


Andrii suggested to remove this abstraction layer and have the percpu
handling more explicit[1].

This patch also updates the tests that relied on the macros.

[1] https://lore.kernel.org/bpf/CAEf4BzYmj_ZPDq8Zi4dbntboJKRPU2TVopysBNrdd9foHTfLZw@xxxxxxxxxxxxxx/

Suggested-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Signed-off-by: Pedro Tammela <pctammela@xxxxxxxxxxxx>
---
tools/testing/selftests/bpf/bpf_util.h | 7 --
.../bpf/map_tests/htab_map_batch_ops.c | 87 +++++++++----------
.../selftests/bpf/prog_tests/map_init.c | 9 +-
tools/testing/selftests/bpf/test_maps.c | 84 +++++++++++-------
4 files changed, 96 insertions(+), 91 deletions(-)

diff --git a/tools/testing/selftests/bpf/bpf_util.h b/tools/testing/selftests/bpf/bpf_util.h
index a3352a64c067..105db3120ab4 100644
--- a/tools/testing/selftests/bpf/bpf_util.h
+++ b/tools/testing/selftests/bpf/bpf_util.h
@@ -20,13 +20,6 @@ static inline unsigned int bpf_num_possible_cpus(void)
return possible_cpus;
}

-#define __bpf_percpu_val_align __attribute__((__aligned__(8)))
-
-#define BPF_DECLARE_PERCPU(type, name) \
- struct { type v; /* padding */ } __bpf_percpu_val_align \
- name[bpf_num_possible_cpus()]
-#define bpf_percpu(name, cpu) name[(cpu)].v
-
#ifndef ARRAY_SIZE
# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
#endif
diff --git a/tools/testing/selftests/bpf/map_tests/htab_map_batch_ops.c b/tools/testing/selftests/bpf/map_tests/htab_map_batch_ops.c
index 976bf415fbdd..8562600ad1df 100644
--- a/tools/testing/selftests/bpf/map_tests/htab_map_batch_ops.c
+++ b/tools/testing/selftests/bpf/map_tests/htab_map_batch_ops.c
@@ -7,65 +7,60 @@
#include <bpf/bpf.h>
#include <bpf/libbpf.h>

-#include <bpf_util.h>
#include <test_maps.h>

+static int nr_cpus;
+
static void map_batch_update(int map_fd, __u32 max_entries, int *keys,
- void *values, bool is_pcpu)
+ __s64 *values, bool is_pcpu)
{
- typedef BPF_DECLARE_PERCPU(int, value);
- value *v = NULL;
int i, j, err;
+ int cpu_offset = 0;
DECLARE_LIBBPF_OPTS(bpf_map_batch_opts, opts,
.elem_flags = 0,
.flags = 0,
);

- 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;
+ if (is_pcpu) {
+ cpu_offset = i * nr_cpus;
+ for (j = 0; j < nr_cpus; j++)
+ (values + cpu_offset)[j] = i + 2 + j;
+
+ } else {
+ values[i] = i + 2;
+ }
}

err = bpf_map_update_batch(map_fd, keys, values, &max_entries, &opts);
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)
+static void map_batch_verify(int *visited, __u32 max_entries, int *keys,
+ __s64 *values, bool is_pcpu)
{
- typedef BPF_DECLARE_PERCPU(int, value);
- value *v = NULL;
int i, j;
-
- if (is_pcpu)
- v = (value *)values;
+ int cpu_offset = 0;

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),
+ cpu_offset = i * nr_cpus;
+ for (j = 0; j < nr_cpus; j++) {
+ __s64 value = (values + cpu_offset)[j];
+ CHECK(keys[i] + 1 + j != value,
"key/value checking",
- "error: i %d j %d key %d value %d\n",
- i, j, keys[i], bpf_percpu(v[i], j));
+ "error: i %d j %d key %d value %lld\n", i,
+ j, keys[i], value);
}
+
} 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]);
+ CHECK(keys[i] + 1 != values[i], "key/value checking",
+ "error: i %d key %d value %lld\n", i, keys[i],
+ values[i]);
}
-
visited[i] = 1;
-
}
for (i = 0; i < max_entries; i++) {
CHECK(visited[i] != 1, "visited checking",
@@ -73,13 +68,11 @@ static void map_batch_verify(int *visited, __u32 max_entries,
}
}

-void __test_map_lookup_and_delete_batch(bool is_pcpu)
+static void __test_map_lookup_and_delete_batch(bool is_pcpu)
{
__u32 batch, count, total, total_success;
- typedef BPF_DECLARE_PERCPU(int, value);
int map_fd, *keys, *visited, key;
const __u32 max_entries = 10;
- value pcpu_values[max_entries];
int err, step, value_size;
bool nospace_err;
void *values;
@@ -88,7 +81,7 @@ void __test_map_lookup_and_delete_batch(bool is_pcpu)
.map_type = is_pcpu ? BPF_MAP_TYPE_PERCPU_HASH :
BPF_MAP_TYPE_HASH,
.key_size = sizeof(int),
- .value_size = sizeof(int),
+ .value_size = sizeof(__s64),
};
DECLARE_LIBBPF_OPTS(bpf_map_batch_opts, opts,
.elem_flags = 0,
@@ -100,13 +93,13 @@ void __test_map_lookup_and_delete_batch(bool is_pcpu)
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));
+ value_size = sizeof(__s64);
if (is_pcpu)
- values = pcpu_values;
- else
- values = malloc(max_entries * sizeof(int));
- visited = malloc(max_entries * sizeof(int));
+ value_size *= nr_cpus;
+
+ keys = calloc(max_entries, sizeof(int));
+ values = calloc(max_entries, value_size);
+ visited = calloc(max_entries, sizeof(int));
CHECK(!keys || !values || !visited, "malloc()",
"error:%s\n", strerror(errno));

@@ -203,7 +196,7 @@ void __test_map_lookup_and_delete_batch(bool is_pcpu)
CHECK(total != max_entries, "delete with steps",
"total = %u, max_entries = %u\n", total, max_entries);

- /* check map is empty, errono == ENOENT */
+ /* check map is empty, errno == ENOENT */
err = bpf_map_get_next_key(map_fd, NULL, &key);
CHECK(!err || errno != ENOENT, "bpf_map_get_next_key()",
"error: %s\n", strerror(errno));
@@ -260,17 +253,16 @@ void __test_map_lookup_and_delete_batch(bool is_pcpu)
"unexpected failure\n");
free(keys);
free(visited);
- if (!is_pcpu)
- free(values);
+ free(values);
}

-void htab_map_batch_ops(void)
+static void htab_map_batch_ops(void)
{
__test_map_lookup_and_delete_batch(false);
printf("test_%s:PASS\n", __func__);
}

-void htab_percpu_map_batch_ops(void)
+static void htab_percpu_map_batch_ops(void)
{
__test_map_lookup_and_delete_batch(true);
printf("test_%s:PASS\n", __func__);
@@ -278,6 +270,11 @@ void htab_percpu_map_batch_ops(void)

void test_htab_map_batch_ops(void)
{
+ nr_cpus = libbpf_num_possible_cpus();
+
+ CHECK(nr_cpus < 0, "nr_cpus checking",
+ "error: get possible cpus failed");
+
htab_map_batch_ops();
htab_percpu_map_batch_ops();
}
diff --git a/tools/testing/selftests/bpf/prog_tests/map_init.c b/tools/testing/selftests/bpf/prog_tests/map_init.c
index 14a31109dd0e..49386d0aa684 100644
--- a/tools/testing/selftests/bpf/prog_tests/map_init.c
+++ b/tools/testing/selftests/bpf/prog_tests/map_init.c
@@ -12,10 +12,7 @@ static int duration;

typedef unsigned long long map_key_t;
typedef unsigned long long map_value_t;
-typedef struct {
- map_value_t v; /* padding */
-} __bpf_percpu_val_align pcpu_map_value_t;
-
+typedef __s64 pcpu_map_value_t;

static int map_populate(int map_fd, int num)
{
@@ -24,7 +21,7 @@ static int map_populate(int map_fd, int num)
map_key_t key;

for (i = 0; i < nr_cpus; i++)
- bpf_percpu(value, i) = FILL_VALUE;
+ value[i] = FILL_VALUE;

for (key = 1; key <= num; key++) {
err = bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST);
@@ -103,7 +100,7 @@ static int check_values_one_cpu(pcpu_map_value_t *value, map_value_t expected)
map_value_t val;

for (i = 0; i < nr_cpus; i++) {
- val = bpf_percpu(value, i);
+ val = value[i];
if (val) {
if (CHECK(val != expected, "map value",
"unexpected for cpu %d: 0x%llx\n", i, val))
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 51adc42b2b40..b8ce837a7ada 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -146,63 +146,69 @@ static void test_hashmap_sizes(unsigned int task, void *data)

static void test_hashmap_percpu(unsigned int task, void *data)
{
- unsigned int nr_cpus = bpf_num_possible_cpus();
- BPF_DECLARE_PERCPU(long, value);
+ int nr_cpus = libbpf_num_possible_cpus();
+ __s64 *values;
long long key, next_key, first_key;
int expected_key_mask = 0;
int fd, i;

+ if (nr_cpus < 0) {
+ printf("Failed get possible cpus\n");
+ exit(1);
+ }
+
+ values = alloca(nr_cpus * sizeof(__s64));
+
fd = bpf_create_map(BPF_MAP_TYPE_PERCPU_HASH, sizeof(key),
- sizeof(bpf_percpu(value, 0)), 2, map_flags);
+ sizeof(*values), 2, map_flags);
if (fd < 0) {
printf("Failed to create hashmap '%s'!\n", strerror(errno));
exit(1);
}

for (i = 0; i < nr_cpus; i++)
- bpf_percpu(value, i) = i + 100;
+ values[i] = i + 100;

key = 1;
/* Insert key=1 element. */
assert(!(expected_key_mask & key));
- assert(bpf_map_update_elem(fd, &key, value, BPF_ANY) == 0);
+ assert(bpf_map_update_elem(fd, &key, values, BPF_ANY) == 0);
expected_key_mask |= key;

/* BPF_NOEXIST means add new element if it doesn't exist. */
- assert(bpf_map_update_elem(fd, &key, value, BPF_NOEXIST) == -1 &&
+ assert(bpf_map_update_elem(fd, &key, values, BPF_NOEXIST) == -1 &&
/* key=1 already exists. */
errno == EEXIST);

/* -1 is an invalid flag. */
- assert(bpf_map_update_elem(fd, &key, value, -1) == -1 &&
+ assert(bpf_map_update_elem(fd, &key, values, -1) == -1 &&
errno == EINVAL);

/* Check that key=1 can be found. Value could be 0 if the lookup
* was run from a different CPU.
*/
- bpf_percpu(value, 0) = 1;
- assert(bpf_map_lookup_elem(fd, &key, value) == 0 &&
- bpf_percpu(value, 0) == 100);
+ values[0] = 1;
+ assert(bpf_map_lookup_elem(fd, &key, values) == 0 && values[0] == 100);

key = 2;
/* Check that key=2 is not found. */
- assert(bpf_map_lookup_elem(fd, &key, value) == -1 && errno == ENOENT);
+ assert(bpf_map_lookup_elem(fd, &key, values) == -1 && errno == ENOENT);

/* BPF_EXIST means update existing element. */
- assert(bpf_map_update_elem(fd, &key, value, BPF_EXIST) == -1 &&
+ assert(bpf_map_update_elem(fd, &key, values, BPF_EXIST) == -1 &&
/* key=2 is not there. */
errno == ENOENT);

/* Insert key=2 element. */
assert(!(expected_key_mask & key));
- assert(bpf_map_update_elem(fd, &key, value, BPF_NOEXIST) == 0);
+ assert(bpf_map_update_elem(fd, &key, values, BPF_NOEXIST) == 0);
expected_key_mask |= key;

/* key=1 and key=2 were inserted, check that key=0 cannot be
* inserted due to max_entries limit.
*/
key = 0;
- assert(bpf_map_update_elem(fd, &key, value, BPF_NOEXIST) == -1 &&
+ assert(bpf_map_update_elem(fd, &key, values, BPF_NOEXIST) == -1 &&
errno == E2BIG);

/* Check that key = 0 doesn't exist. */
@@ -219,10 +225,10 @@ static void test_hashmap_percpu(unsigned int task, void *data)
assert((expected_key_mask & next_key) == next_key);
expected_key_mask &= ~next_key;

- assert(bpf_map_lookup_elem(fd, &next_key, value) == 0);
+ assert(bpf_map_lookup_elem(fd, &next_key, values) == 0);

for (i = 0; i < nr_cpus; i++)
- assert(bpf_percpu(value, i) == i + 100);
+ assert(values[i] == i + 100);

key = next_key;
}
@@ -230,7 +236,7 @@ static void test_hashmap_percpu(unsigned int task, void *data)

/* Update with BPF_EXIST. */
key = 1;
- assert(bpf_map_update_elem(fd, &key, value, BPF_EXIST) == 0);
+ assert(bpf_map_update_elem(fd, &key, values, BPF_EXIST) == 0);

/* Delete both elements. */
key = 1;
@@ -399,37 +405,42 @@ static void test_arraymap(unsigned int task, void *data)

static void test_arraymap_percpu(unsigned int task, void *data)
{
- unsigned int nr_cpus = bpf_num_possible_cpus();
- BPF_DECLARE_PERCPU(long, values);
+ int nr_cpus = libbpf_num_possible_cpus();
+ __s64 *values;
int key, next_key, fd, i;

+ if (nr_cpus < 0) {
+ printf("Failed get possible cpus\n");
+ exit(1);
+ }
+
+ values = alloca(nr_cpus * sizeof(__s64));
+
fd = bpf_create_map(BPF_MAP_TYPE_PERCPU_ARRAY, sizeof(key),
- sizeof(bpf_percpu(values, 0)), 2, 0);
+ sizeof(*values), 2, 0);
if (fd < 0) {
printf("Failed to create arraymap '%s'!\n", strerror(errno));
exit(1);
}

for (i = 0; i < nr_cpus; i++)
- bpf_percpu(values, i) = i + 100;
+ values[i] = i + 100;

key = 1;
/* Insert key=1 element. */
assert(bpf_map_update_elem(fd, &key, values, BPF_ANY) == 0);

- bpf_percpu(values, 0) = 0;
+ values[0] = 0;
assert(bpf_map_update_elem(fd, &key, values, BPF_NOEXIST) == -1 &&
errno == EEXIST);

/* Check that key=1 can be found. */
- assert(bpf_map_lookup_elem(fd, &key, values) == 0 &&
- bpf_percpu(values, 0) == 100);
+ assert(bpf_map_lookup_elem(fd, &key, values) == 0 && values[0] == 100);

key = 0;
/* Check that key=0 is also found and zero initialized. */
- assert(bpf_map_lookup_elem(fd, &key, values) == 0 &&
- bpf_percpu(values, 0) == 0 &&
- bpf_percpu(values, nr_cpus - 1) == 0);
+ assert(bpf_map_lookup_elem(fd, &key, values) == 0 && values[0] == 0 &&
+ values[nr_cpus - 1] == 0);

/* Check that key=2 cannot be inserted due to max_entries limit. */
key = 2;
@@ -458,16 +469,23 @@ static void test_arraymap_percpu(unsigned int task, void *data)

static void test_arraymap_percpu_many_keys(void)
{
- unsigned int nr_cpus = bpf_num_possible_cpus();
- BPF_DECLARE_PERCPU(long, values);
+ unsigned int nr_cpus = libbpf_num_possible_cpus();
+ __s64 *values;
/* nr_keys is not too large otherwise the test stresses percpu
* allocator more than anything else
*/
unsigned int nr_keys = 2000;
int key, fd, i;

+ if (nr_cpus < 0) {
+ printf("Failed get possible cpus\n");
+ exit(1);
+ }
+
+ values = alloca(nr_cpus * sizeof(__s64));
+
fd = bpf_create_map(BPF_MAP_TYPE_PERCPU_ARRAY, sizeof(key),
- sizeof(bpf_percpu(values, 0)), nr_keys, 0);
+ sizeof(*values), nr_keys, 0);
if (fd < 0) {
printf("Failed to create per-cpu arraymap '%s'!\n",
strerror(errno));
@@ -475,19 +493,19 @@ static void test_arraymap_percpu_many_keys(void)
}

for (i = 0; i < nr_cpus; i++)
- bpf_percpu(values, i) = i + 10;
+ values[i] = i + 10;

for (key = 0; key < nr_keys; key++)
assert(bpf_map_update_elem(fd, &key, values, BPF_ANY) == 0);

for (key = 0; key < nr_keys; key++) {
for (i = 0; i < nr_cpus; i++)
- bpf_percpu(values, i) = 0;
+ values[i] = 0;

assert(bpf_map_lookup_elem(fd, &key, values) == 0);

for (i = 0; i < nr_cpus; i++)
- assert(bpf_percpu(values, i) == i + 10);
+ assert(values[i] == i + 10);
}

close(fd);
--
2.25.1