Hou Tao 73b97bc78b selftests/bpf: Test concurrent updates on bpf_task_storage_busy ... Under full preemptible kernel, task local storage lookup operations on the same CPU may update per-cpu bpf_task_storage_busy concurrently. If the update of bpf_task_storage_busy is not preemption safe, the final value of bpf_task_storage_busy may become not-zero forever and bpf_task_storage_trylock() will always fail. So add a test case to ensure the update of bpf_task_storage_busy is preemption safe. Will skip the test case when CONFIG_PREEMPT is disabled, and it can only reproduce the problem probabilistically. By increasing TASK_STORAGE_MAP_NR_LOOP and running it under ARM64 VM with 4-cpus, it takes about four rounds to reproduce: > test_maps is modified to only run test_task_storage_map_stress_lookup() $ export TASK_STORAGE_MAP_NR_THREAD=256 $ export TASK_STORAGE_MAP_NR_LOOP=81920 $ export TASK_STORAGE_MAP_PIN_CPU=1 $ time ./test_maps test_task_storage_map_stress_lookup(135):FAIL:bad bpf_task_storage_busy got -2 real 0m24.743s user 0m6.772s sys 0m17.966s Signed-off-by: Hou Tao <houtao1@huawei.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/r/20220901061938.3789460-5-houtao@huaweicloud.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>		2022-09-01 12:16:21 -07:00
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.gitignore	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
array_map_batch_ops.c	selftests/bpf: Migrate selftests to bpf_map_create()	2021-11-25 23:37:38 +01:00
htab_map_batch_ops.c	selftests/bpf: Migrate selftests to bpf_map_create()	2021-11-25 23:37:38 +01:00
lpm_trie_map_batch_ops.c	selftests/bpf: Migrate selftests to bpf_map_create()	2021-11-25 23:37:38 +01:00
map_in_map_batch_ops.c	selftests/bpf: Handle batch operations for map-in-map bpf-maps	2022-05-10 10:34:57 -07:00
sk_storage_map.c	selftests/bpf: Replace all uses of bpf_load_btf() with bpf_btf_load()	2021-12-10 15:29:18 -08:00
task_storage_map.c	selftests/bpf: Test concurrent updates on bpf_task_storage_busy	2022-09-01 12:16:21 -07:00