From 3c3bd542ffbb2ac09631313ede46ae66660ae550 Mon Sep 17 00:00:00 2001 From: Yucong Sun Date: Mon, 16 Aug 2021 10:52:50 -0700 Subject: [PATCH] selftests/bpf: Add exponential backoff to map_update_retriable in test_maps Using a fixed delay of 1 microsecond has proven flaky in slow CPU environment, e.g. Github Actions CI system. This patch adds exponential backoff with a cap of 50ms to reduce the flakiness of the test. Initial delay is chosen at random in the range [0ms, 5ms). Signed-off-by: Yucong Sun Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20210816175250.296110-1-fallentree@fb.com --- tools/testing/selftests/bpf/test_maps.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c index 14cea869235b1..2caf58b40d402 100644 --- a/tools/testing/selftests/bpf/test_maps.c +++ b/tools/testing/selftests/bpf/test_maps.c @@ -1396,15 +1396,22 @@ static void test_map_stress(void) #define DO_DELETE 0 #define MAP_RETRIES 20 +#define MAX_DELAY_US 50000 +#define MIN_DELAY_RANGE_US 5000 static int map_update_retriable(int map_fd, const void *key, const void *value, int flags, int attempts) { + int delay = rand() % MIN_DELAY_RANGE_US; + while (bpf_map_update_elem(map_fd, key, value, flags)) { if (!attempts || (errno != EAGAIN && errno != EBUSY)) return -errno; - usleep(1); + if (delay <= MAX_DELAY_US / 2) + delay *= 2; + + usleep(delay); attempts--; } -- 2.30.2