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bpf: lru: Add map-in-map LRU example

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This patch adds a map-in-map LRU example.
If we know only a subset of cores will use the
LRU, we can allocate a common LRU list per targeting core
and store it into an array-of-hashs.

It allows using the common LRU map with map-update performance
comparable to the BPF_F_NO_COMMON_LRU map but without wasting memory
on the unused cores that we know they will never access the LRU map.

BPF_F_NO_COMMON_LRU:
> map_perf_test 32 8 10000000 10000000 | awk '{sum += $3}END{print sum}'
9234314 (9.23M/s)

map-in-map LRU:
> map_perf_test 512 8 1260000 80000000 | awk '{sum += $3}END{print sum}'
9962743 (9.96M/s)

Notes that the max_entries for the map-in-map LRU test is 1260000 which
is the max_entries for each inner LRU map.  8 processes have been
started, so 8 * 1260000 = 10080000 (~10M) which is close to what is
used in the BPF_F_NO_COMMON_LRU test.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Martin KaFai Lau 2017-04-14 10:30:30 -07:00 committed by David S. Miller
parent 695ba2651a
commit 3a5795b83d
2 changed files with 93 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
samples/bpf/map_perf_test_kern.c
View File

@ -11,6 +11,7 @@
#include "bpf_helpers.h"
#define MAX_ENTRIES 1000
#define MAX_NR_CPUS 1024
struct bpf_map_def SEC("maps") hash_map = {
.type = BPF_MAP_TYPE_HASH,
@ -34,6 +35,19 @@ struct bpf_map_def SEC("maps") nocommon_lru_hash_map = {
.map_flags = BPF_F_NO_COMMON_LRU,
};
struct bpf_map_def SEC("maps") inner_lru_hash_map = {
.type = BPF_MAP_TYPE_LRU_HASH,
.key_size = sizeof(u32),
.value_size = sizeof(long),
.max_entries = MAX_ENTRIES,
};
struct bpf_map_def SEC("maps") array_of_lru_hashs = {
.type = BPF_MAP_TYPE_ARRAY_OF_MAPS,
.key_size = sizeof(u32),
.max_entries = MAX_NR_CPUS,
};
struct bpf_map_def SEC("maps") percpu_hash_map = {
.type = BPF_MAP_TYPE_PERCPU_HASH,
.key_size = sizeof(u32),
@ -154,13 +168,27 @@ int stress_lru_hmap_alloc(struct pt_regs *ctx)
test_case = dst6[7];
if (test_case == 0)
if (test_case == 0) {
ret = bpf_map_update_elem(&lru_hash_map, &key, &val, BPF_ANY);
else if (test_case == 1)
} else if (test_case == 1) {
ret = bpf_map_update_elem(&nocommon_lru_hash_map, &key, &val,
BPF_ANY);
else
} else if (test_case == 2) {
void *nolocal_lru_map;
int cpu = bpf_get_smp_processor_id();
nolocal_lru_map = bpf_map_lookup_elem(&array_of_lru_hashs,
&cpu);
if (!nolocal_lru_map) {
ret = -ENOENT;
goto done;
}
ret = bpf_map_update_elem(nolocal_lru_map, &key, &val,
BPF_ANY);
} else {
ret = -EINVAL;
}
done:
if (ret)

62
samples/bpf/map_perf_test_user.c
View File

@ -25,6 +25,7 @@
#include "bpf_load.h"
#define TEST_BIT(t) (1U << (t))
#define MAX_NR_CPUS 1024
static __u64 time_get_ns(void)
{
@ -44,6 +45,7 @@ enum test_type {
LPM_KMALLOC,
HASH_LOOKUP,
ARRAY_LOOKUP,
INNER_LRU_HASH_PREALLOC,
NR_TESTS,
};
@ -57,10 +59,14 @@ const char *test_map_names[NR_TESTS] = {
[LPM_KMALLOC] = "lpm_trie_map_alloc",
[HASH_LOOKUP] = "hash_map",
[ARRAY_LOOKUP] = "array_map",
[INNER_LRU_HASH_PREALLOC] = "inner_lru_hash_map",
};
static int test_flags = ~0;
static uint32_t num_map_entries;
static uint32_t inner_lru_hash_size;
static int inner_lru_hash_idx = -1;
static int array_of_lru_hashs_idx = -1;
static uint32_t max_cnt = 1000000;
static int check_test_flags(enum test_type t)
@ -82,11 +88,42 @@ static void test_hash_prealloc(int cpu)
static void do_test_lru(enum test_type test, int cpu)
{
static int inner_lru_map_fds[MAX_NR_CPUS];
struct sockaddr_in6 in6 = { .sin6_family = AF_INET6 };
const char *test_name;
__u64 start_time;
int i, ret;
if (test == INNER_LRU_HASH_PREALLOC) {
int outer_fd = map_fd[array_of_lru_hashs_idx];
assert(cpu < MAX_NR_CPUS);
if (cpu) {
inner_lru_map_fds[cpu] =
bpf_create_map(BPF_MAP_TYPE_LRU_HASH,
sizeof(uint32_t), sizeof(long),
inner_lru_hash_size, 0);
if (inner_lru_map_fds[cpu] == -1) {
printf("cannot create BPF_MAP_TYPE_LRU_HASH %s(%d)\n",
strerror(errno), errno);
exit(1);
}
} else {
inner_lru_map_fds[cpu] = map_fd[inner_lru_hash_idx];
}
ret = bpf_map_update_elem(outer_fd, &cpu,
&inner_lru_map_fds[cpu],
BPF_ANY);
if (ret) {
printf("cannot update ARRAY_OF_LRU_HASHS with key:%u. %s(%d)\n",
cpu, strerror(errno), errno);
exit(1);
}
}
in6.sin6_addr.s6_addr16[0] = 0xdead;
in6.sin6_addr.s6_addr16[1] = 0xbeef;
@ -96,6 +133,9 @@ static void do_test_lru(enum test_type test, int cpu)
} else if (test == NOCOMMON_LRU_HASH_PREALLOC) {
test_name = "nocommon_lru_hash_map_perf";
in6.sin6_addr.s6_addr16[7] = 1;
} else if (test == INNER_LRU_HASH_PREALLOC) {
test_name = "inner_lru_hash_map_perf";
in6.sin6_addr.s6_addr16[7] = 2;
} else {
assert(0);
}
@ -120,6 +160,11 @@ static void test_nocommon_lru_hash_prealloc(int cpu)
do_test_lru(NOCOMMON_LRU_HASH_PREALLOC, cpu);
}
static void test_inner_lru_hash_prealloc(int cpu)
{
do_test_lru(INNER_LRU_HASH_PREALLOC, cpu);
}
static void test_percpu_hash_prealloc(int cpu)
{
__u64 start_time;
@ -203,6 +248,7 @@ const test_func test_funcs[] = {
[LPM_KMALLOC] = test_lpm_kmalloc,
[HASH_LOOKUP] = test_hash_lookup,
[ARRAY_LOOKUP] = test_array_lookup,
[INNER_LRU_HASH_PREALLOC] = test_inner_lru_hash_prealloc,
};
static void loop(int cpu)
@ -278,9 +324,25 @@ static void fixup_map(struct bpf_map_def *map, const char *name, int idx)
{
int i;
if (!strcmp("inner_lru_hash_map", name)) {
inner_lru_hash_idx = idx;
inner_lru_hash_size = map->max_entries;
}
if (!strcmp("array_of_lru_hashs", name)) {
if (inner_lru_hash_idx == -1) {
printf("inner_lru_hash_map must be defined before array_of_lru_hashs\n");
exit(1);
}
map->inner_map_idx = inner_lru_hash_idx;
array_of_lru_hashs_idx = idx;
}
if (num_map_entries <= 0)
return;
inner_lru_hash_size = num_map_entries;
/* Only change the max_entries for the enabled test(s) */
for (i = 0; i < NR_TESTS; i++) {
if (!strcmp(test_map_names[i], name) &&