kernel/tools/testing/selftests/bpf/test_lru_map.c, branch linux-rolling-stable

selftests/bpf: adapt one more case in test_lru_map to the new target_free

2025-07-17T16:44:04Z

commit 5e9388f7984a9cc7e659a105113f6ccf0aebedd0 upstream. 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 Link: https://lore.kernel.org/r/20250625210412.2732970-1-willemdebruijn.kernel@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman

bpf: Adjust free target to avoid global starvation of LRU map

2025-07-17T16:44:03Z

[ Upstream commit d4adf1c9ee7722545450608bcb095fb31512f0c6 ] BPF_MAP_TYPE_LRU_HASH can recycle most recent elements well before the map is full, due to percpu reservations and force shrink before neighbor stealing. Once a CPU is unable to borrow from the global map, it will once steal one elem from a neighbor and after that each time flush this one element to the global list and immediately recycle it. Batch value LOCAL_FREE_TARGET (128) will exhaust a 10K element map with 79 CPUs. CPU 79 will observe this behavior even while its neighbors hold 78 * 127 + 1 * 15 == 9921 free elements (99%). CPUs need not be active concurrently. The issue can appear with affinity migration, e.g., irqbalance. Each CPU can reserve and then hold onto its 128 elements indefinitely. Avoid global list exhaustion by limiting aggregate percpu caches to half of map size, by adjusting LOCAL_FREE_TARGET based on cpu count. This change has no effect on sufficiently large tables. Similar to LOCAL_NR_SCANS and lru->nr_scans, introduce a map variable lru->free_target. The extra field fits in a hole in struct bpf_lru. The cacheline is already warm where read in the hot path. The field is only accessed with the lru lock held. Tested-by: Anton Protopopov Signed-off-by: Willem de Bruijn Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20250618215803.3587312-1-willemdebruijn.kernel@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

selftests/bpf: Fix error compiling test_lru_map.c

2024-07-30T20:45:45Z

Although the post-increment in macro 'CPU_SET(next++, &cpuset)' seems safe, the sequencing can raise compile errors, so move the increment outside the macro. This avoids an error seen using gcc 12.3.0 for mips64el/musl-libc: In file included from test_lru_map.c:11: test_lru_map.c: In function 'sched_next_online': test_lru_map.c:129:29: error: operation on 'next' may be undefined [-Werror=sequence-point] 129 | CPU_SET(next++, &cpuset); | ^ cc1: all warnings being treated as errors Fixes: 3fbfadce6012 ("bpf: Fix test_lru_sanity5() in test_lru_map.c") Signed-off-by: Tony Ambardar Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/22993dfb11ccf27925a626b32672fd3324cb76c4.1722244708.git.tony.ambardar@gmail.com

selftests/bpf: Fix map tests errno checks

2022-04-21T16:51:57Z

Switching to libbpf 1.0 API broke test_lpm_map and test_lru_map as error reporting changed. Instead of setting errno and returning -1 bpf calls now return -Exxx directly. Drop errno checks and look at return code directly. Fixes: b858ba8c52b6 ("selftests/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK") Signed-off-by: Artem Savkov Signed-off-by: Andrii Nakryiko Reviewed-by: Yafang Shao Link: https://lore.kernel.org/bpf/20220421094320.1563570-1-asavkov@redhat.com

selftests/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK

2022-04-11T03:17:16Z

We have switched to memcg-based memory accouting and thus the rlimit is not needed any more. LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK was introduced in libbpf for backward compatibility, so we can use it instead now. After this change, the header tools/testing/selftests/bpf/bpf_rlimit.h can be removed. This patch also removes the useless header sys/resource.h from many files in tools/testing/selftests/bpf/. Signed-off-by: Yafang Shao Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220409125958.92629-3-laoar.shao@gmail.com

selftests/bpf: Clean up array_size.cocci warnings

2022-03-15T16:03:10Z

Clean up the array_size.cocci warnings under tools/testing/selftests/bpf/: Use `ARRAY_SIZE(arr)` instead of forms like `sizeof(arr)/sizeof(arr[0])`. tools/testing/selftests/bpf/test_cgroup_storage.c uses ARRAY_SIZE() defined in tools/include/linux/kernel.h (sys/sysinfo.h -> linux/kernel.h), while others use ARRAY_SIZE() in bpf_util.h. Signed-off-by: Guo Zhengkui Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220315130143.2403-1-guozhengkui@vivo.com

selftests/bpf: Migrate from bpf_prog_test_run

2022-02-03T06:31:18Z

bpf_prog_test_run is being deprecated in favor of the OPTS-based bpf_prog_test_run_opts. We end up unable to use CHECK in most cases, so replace usages with ASSERT_* calls. Signed-off-by: Delyan Kratunov Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220202235423.1097270-2-delyank@fb.com

selftests/bpf: Migrate selftests to bpf_map_create()

2021-11-25T22:37:38Z

Conversion is straightforward for most cases. In few cases tests are using mutable map_flags and attribute structs, but bpf_map_create_opts can be used in the similar fashion, so there were no problems. Just lots of repetitive conversions. Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20211124193233.3115996-5-andrii@kernel.org

selftests/bpf: Convert legacy prog load APIs to bpf_prog_load()

2021-11-07T16:34:23Z

Convert all the uses of legacy low-level BPF program loading APIs (mostly bpf_load_program_xattr(), but also some bpf_verify_program()) to bpf_prog_load() uses. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20211103220845.2676888-10-andrii@kernel.org

selftests/bpf: Add bpf_lookup_and_delete_elem tests

2021-05-24T20:30:52Z

Add bpf selftests and extend existing ones for a new function bpf_lookup_and_delete_elem() for (percpu) hash and (percpu) LRU hash map types. In test_lru_map and test_maps we add an element, lookup_and_delete it, then check whether it's deleted. The newly added lookup_and_delete prog tests practically do the same thing but additionally use a BPF program to change the value of the element for LRU maps. Signed-off-by: Denis Salopek Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/d30d3e0060c1f750e133579623cf1c60ff58f3d9.1620763117.git.denis.salopek@sartura.hr