diff options
| author | Willem de Bruijn <willemb@google.com> | 2025-06-25 17:03:55 -0400 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-06-25 15:19:36 -0700 |
| commit | 5e9388f7984a9cc7e659a105113f6ccf0aebedd0 (patch) | |
| tree | 470fef817609f152f1a28d23bc780984a5d6e08b | |
| parent | fa6f092cc0a02d0fcee37e9e8172eda372a03d33 (diff) | |
selftests/bpf: adapt one more case in test_lru_map to the new target_free
The below commit that updated BPF_MAP_TYPE_LRU_HASH free target,
also updated tools/testing/selftests/bpf/test_lru_map to match.
But that missed one case that passes with 4 cores, but fails at
higher cpu counts.
Update test_lru_sanity3 to also adjust its expectation of target_free.
This time tested with 1, 4, 16, 64 and 384 cpu count.
Fixes: d4adf1c9ee77 ("bpf: Adjust free target to avoid global starvation of LRU map")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20250625210412.2732970-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/testing/selftests/bpf/test_lru_map.c | 33 |
1 files changed, 18 insertions, 15 deletions
diff --git a/tools/testing/selftests/bpf/test_lru_map.c b/tools/testing/selftests/bpf/test_lru_map.c index 4ae83f4b7fc7..0921939532c6 100644 --- a/tools/testing/selftests/bpf/test_lru_map.c +++ b/tools/testing/selftests/bpf/test_lru_map.c @@ -138,6 +138,12 @@ static int sched_next_online(int pid, int *next_to_try) return ret; } +/* Derive target_free from map_size, same as bpf_common_lru_populate */ +static unsigned int __tgt_size(unsigned int map_size) +{ + return (map_size / nr_cpus) / 2; +} + /* Inverse of how bpf_common_lru_populate derives target_free from map_size. */ static unsigned int __map_size(unsigned int tgt_free) { @@ -410,12 +416,12 @@ static void test_lru_sanity2(int map_type, int map_flags, unsigned int tgt_free) printf("Pass\n"); } -/* Size of the LRU map is 2*tgt_free - * It is to test the active/inactive list rotation - * Insert 1 to 2*tgt_free (+2*tgt_free keys) - * Lookup key 1 to tgt_free*3/2 - * Add 1+2*tgt_free to tgt_free*5/2 (+tgt_free/2 keys) - * => key 1+tgt_free*3/2 to 2*tgt_free are removed from LRU +/* Test the active/inactive list rotation + * + * Fill the whole map, deplete the free list. + * Reference all except the last lru->target_free elements. + * Insert lru->target_free new elements. This triggers one shrink. + * Verify that the non-referenced elements are replaced. */ static void test_lru_sanity3(int map_type, int map_flags, unsigned int tgt_free) { @@ -434,8 +440,7 @@ static void test_lru_sanity3(int map_type, int map_flags, unsigned int tgt_free) assert(sched_next_online(0, &next_cpu) != -1); - batch_size = tgt_free / 2; - assert(batch_size * 2 == tgt_free); + batch_size = __tgt_size(tgt_free); map_size = tgt_free * 2; lru_map_fd = create_map(map_type, map_flags, map_size); @@ -446,23 +451,21 @@ static void test_lru_sanity3(int map_type, int map_flags, unsigned int tgt_free) value[0] = 1234; - /* Insert 1 to 2*tgt_free (+2*tgt_free keys) */ - end_key = 1 + (2 * tgt_free); + /* Fill the map */ + end_key = 1 + map_size; for (key = 1; key < end_key; key++) assert(!bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST)); - /* Lookup key 1 to tgt_free*3/2 */ - end_key = tgt_free + batch_size; + /* Reference all but the last batch_size */ + end_key = 1 + map_size - batch_size; for (key = 1; key < end_key; key++) { assert(!bpf_map_lookup_elem_with_ref_bit(lru_map_fd, key, value)); assert(!bpf_map_update_elem(expected_map_fd, &key, value, BPF_NOEXIST)); } - /* Add 1+2*tgt_free to tgt_free*5/2 - * (+tgt_free/2 keys) - */ + /* Insert new batch_size: replaces the non-referenced elements */ key = 2 * tgt_free + 1; end_key = key + batch_size; for (; key < end_key; key++) { |