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selftests/bpf: Add more test cases for bpf memory allocator
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Add the following 3 test cases for bpf memory allocator:
1) Do allocation in bpf program and free through map free
2) Do batch per-cpu allocation and per-cpu free in bpf program
3) Do per-cpu allocation in bpf program and free through map free

For per-cpu allocation, because per-cpu allocation can not refill timely
sometimes, so test 2) and test 3) consider it is OK for
bpf_percpu_obj_new_impl() to return NULL.

Signed-off-by: Hou Tao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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Hou Tao authored and Alexei Starovoitov committed Oct 20, 2023
1 parent e383a45 commit d440ba9
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Showing 2 changed files with 193 additions and 7 deletions.
20 changes: 19 additions & 1 deletion tools/testing/selftests/bpf/prog_tests/test_bpf_ma.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -9,9 +9,10 @@

#include "test_bpf_ma.skel.h"

void test_test_bpf_ma(void)
static void do_bpf_ma_test(const char *name)
{
struct test_bpf_ma *skel;
struct bpf_program *prog;
struct btf *btf;
int i, err;

Expand All @@ -34,6 +35,11 @@ void test_test_bpf_ma(void)
skel->rodata->data_btf_ids[i] = id;
}

prog = bpf_object__find_program_by_name(skel->obj, name);
if (!ASSERT_OK_PTR(prog, "invalid prog name"))
goto out;
bpf_program__set_autoload(prog, true);

err = test_bpf_ma__load(skel);
if (!ASSERT_OK(err, "load"))
goto out;
Expand All @@ -48,3 +54,15 @@ void test_test_bpf_ma(void)
out:
test_bpf_ma__destroy(skel);
}

void test_test_bpf_ma(void)
{
if (test__start_subtest("batch_alloc_free"))
do_bpf_ma_test("test_batch_alloc_free");
if (test__start_subtest("free_through_map_free"))
do_bpf_ma_test("test_free_through_map_free");
if (test__start_subtest("batch_percpu_alloc_free"))
do_bpf_ma_test("test_batch_percpu_alloc_free");
if (test__start_subtest("percpu_free_through_map_free"))
do_bpf_ma_test("test_percpu_free_through_map_free");
}
180 changes: 174 additions & 6 deletions tools/testing/selftests/bpf/progs/test_bpf_ma.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -37,10 +37,20 @@ int pid = 0;
__type(key, int); \
__type(value, struct map_value_##_size); \
__uint(max_entries, 128); \
} array_##_size SEC(".maps");
} array_##_size SEC(".maps")

static __always_inline void batch_alloc_free(struct bpf_map *map, unsigned int batch,
unsigned int idx)
#define DEFINE_ARRAY_WITH_PERCPU_KPTR(_size) \
struct map_value_percpu_##_size { \
struct bin_data_##_size __percpu_kptr * data; \
}; \
struct { \
__uint(type, BPF_MAP_TYPE_ARRAY); \
__type(key, int); \
__type(value, struct map_value_percpu_##_size); \
__uint(max_entries, 128); \
} array_percpu_##_size SEC(".maps")

static __always_inline void batch_alloc(struct bpf_map *map, unsigned int batch, unsigned int idx)
{
struct generic_map_value *value;
unsigned int i, key;
Expand All @@ -65,6 +75,14 @@ static __always_inline void batch_alloc_free(struct bpf_map *map, unsigned int b
return;
}
}
}

static __always_inline void batch_free(struct bpf_map *map, unsigned int batch, unsigned int idx)
{
struct generic_map_value *value;
unsigned int i, key;
void *old;

for (i = 0; i < batch; i++) {
key = i;
value = bpf_map_lookup_elem(map, &key);
Expand All @@ -81,8 +99,72 @@ static __always_inline void batch_alloc_free(struct bpf_map *map, unsigned int b
}
}

static __always_inline void batch_percpu_alloc(struct bpf_map *map, unsigned int batch,
unsigned int idx)
{
struct generic_map_value *value;
unsigned int i, key;
void *old, *new;

for (i = 0; i < batch; i++) {
key = i;
value = bpf_map_lookup_elem(map, &key);
if (!value) {
err = 1;
return;
}
/* per-cpu allocator may not be able to refill in time */
new = bpf_percpu_obj_new_impl(data_btf_ids[idx], NULL);
if (!new)
continue;

old = bpf_kptr_xchg(&value->data, new);
if (old) {
bpf_percpu_obj_drop(old);
err = 2;
return;
}
}
}

static __always_inline void batch_percpu_free(struct bpf_map *map, unsigned int batch,
unsigned int idx)
{
struct generic_map_value *value;
unsigned int i, key;
void *old;

for (i = 0; i < batch; i++) {
key = i;
value = bpf_map_lookup_elem(map, &key);
if (!value) {
err = 3;
return;
}
old = bpf_kptr_xchg(&value->data, NULL);
if (!old)
continue;
bpf_percpu_obj_drop(old);
}
}

#define CALL_BATCH_ALLOC(size, batch, idx) \
batch_alloc((struct bpf_map *)(&array_##size), batch, idx)

#define CALL_BATCH_ALLOC_FREE(size, batch, idx) \
batch_alloc_free((struct bpf_map *)(&array_##size), batch, idx)
do { \
batch_alloc((struct bpf_map *)(&array_##size), batch, idx); \
batch_free((struct bpf_map *)(&array_##size), batch, idx); \
} while (0)

#define CALL_BATCH_PERCPU_ALLOC(size, batch, idx) \
batch_percpu_alloc((struct bpf_map *)(&array_percpu_##size), batch, idx)

#define CALL_BATCH_PERCPU_ALLOC_FREE(size, batch, idx) \
do { \
batch_percpu_alloc((struct bpf_map *)(&array_percpu_##size), batch, idx); \
batch_percpu_free((struct bpf_map *)(&array_percpu_##size), batch, idx); \
} while (0)

DEFINE_ARRAY_WITH_KPTR(8);
DEFINE_ARRAY_WITH_KPTR(16);
Expand All @@ -97,8 +179,21 @@ DEFINE_ARRAY_WITH_KPTR(1024);
DEFINE_ARRAY_WITH_KPTR(2048);
DEFINE_ARRAY_WITH_KPTR(4096);

SEC("fentry/" SYS_PREFIX "sys_nanosleep")
int test_bpf_mem_alloc_free(void *ctx)
/* per-cpu kptr doesn't support bin_data_8 which is a zero-sized array */
DEFINE_ARRAY_WITH_PERCPU_KPTR(16);
DEFINE_ARRAY_WITH_PERCPU_KPTR(32);
DEFINE_ARRAY_WITH_PERCPU_KPTR(64);
DEFINE_ARRAY_WITH_PERCPU_KPTR(96);
DEFINE_ARRAY_WITH_PERCPU_KPTR(128);
DEFINE_ARRAY_WITH_PERCPU_KPTR(192);
DEFINE_ARRAY_WITH_PERCPU_KPTR(256);
DEFINE_ARRAY_WITH_PERCPU_KPTR(512);
DEFINE_ARRAY_WITH_PERCPU_KPTR(1024);
DEFINE_ARRAY_WITH_PERCPU_KPTR(2048);
DEFINE_ARRAY_WITH_PERCPU_KPTR(4096);

SEC("?fentry/" SYS_PREFIX "sys_nanosleep")
int test_batch_alloc_free(void *ctx)
{
if ((u32)bpf_get_current_pid_tgid() != pid)
return 0;
Expand All @@ -121,3 +216,76 @@ int test_bpf_mem_alloc_free(void *ctx)

return 0;
}

SEC("?fentry/" SYS_PREFIX "sys_nanosleep")
int test_free_through_map_free(void *ctx)
{
if ((u32)bpf_get_current_pid_tgid() != pid)
return 0;

/* Alloc 128 8-bytes objects in batch to trigger refilling,
* then free these objects through map free.
*/
CALL_BATCH_ALLOC(8, 128, 0);
CALL_BATCH_ALLOC(16, 128, 1);
CALL_BATCH_ALLOC(32, 128, 2);
CALL_BATCH_ALLOC(64, 128, 3);
CALL_BATCH_ALLOC(96, 128, 4);
CALL_BATCH_ALLOC(128, 128, 5);
CALL_BATCH_ALLOC(192, 128, 6);
CALL_BATCH_ALLOC(256, 128, 7);
CALL_BATCH_ALLOC(512, 64, 8);
CALL_BATCH_ALLOC(1024, 32, 9);
CALL_BATCH_ALLOC(2048, 16, 10);
CALL_BATCH_ALLOC(4096, 8, 11);

return 0;
}

SEC("?fentry/" SYS_PREFIX "sys_nanosleep")
int test_batch_percpu_alloc_free(void *ctx)
{
if ((u32)bpf_get_current_pid_tgid() != pid)
return 0;

/* Alloc 128 16-bytes per-cpu objects in batch to trigger refilling,
* then free 128 16-bytes per-cpu objects in batch to trigger freeing.
*/
CALL_BATCH_PERCPU_ALLOC_FREE(16, 128, 1);
CALL_BATCH_PERCPU_ALLOC_FREE(32, 128, 2);
CALL_BATCH_PERCPU_ALLOC_FREE(64, 128, 3);
CALL_BATCH_PERCPU_ALLOC_FREE(96, 128, 4);
CALL_BATCH_PERCPU_ALLOC_FREE(128, 128, 5);
CALL_BATCH_PERCPU_ALLOC_FREE(192, 128, 6);
CALL_BATCH_PERCPU_ALLOC_FREE(256, 128, 7);
CALL_BATCH_PERCPU_ALLOC_FREE(512, 64, 8);
CALL_BATCH_PERCPU_ALLOC_FREE(1024, 32, 9);
CALL_BATCH_PERCPU_ALLOC_FREE(2048, 16, 10);
CALL_BATCH_PERCPU_ALLOC_FREE(4096, 8, 11);

return 0;
}

SEC("?fentry/" SYS_PREFIX "sys_nanosleep")
int test_percpu_free_through_map_free(void *ctx)
{
if ((u32)bpf_get_current_pid_tgid() != pid)
return 0;

/* Alloc 128 16-bytes per-cpu objects in batch to trigger refilling,
* then free these object through map free.
*/
CALL_BATCH_PERCPU_ALLOC(16, 128, 1);
CALL_BATCH_PERCPU_ALLOC(32, 128, 2);
CALL_BATCH_PERCPU_ALLOC(64, 128, 3);
CALL_BATCH_PERCPU_ALLOC(96, 128, 4);
CALL_BATCH_PERCPU_ALLOC(128, 128, 5);
CALL_BATCH_PERCPU_ALLOC(192, 128, 6);
CALL_BATCH_PERCPU_ALLOC(256, 128, 7);
CALL_BATCH_PERCPU_ALLOC(512, 64, 8);
CALL_BATCH_PERCPU_ALLOC(1024, 32, 9);
CALL_BATCH_PERCPU_ALLOC(2048, 16, 10);
CALL_BATCH_PERCPU_ALLOC(4096, 8, 11);

return 0;
}

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