From: Hou Tao <houtao1@xxxxxxxxxx>
Use BPF_MA_NO_REUSE in htab map to disable the immediate reuse of free
elements, so the lookup procedure will not return incorrect result.
After the change, the performance of "./map_perf_test 4 18 8192" will
drop from 520K to 330K events per sec on one CPU.
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
kernel/bpf/hashtab.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 623111d4276d..e1636c5d0051 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -574,14 +574,14 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
goto free_prealloc;
}
} else {
- err = bpf_mem_alloc_init(&htab->ma, htab->elem_size, 0,
+ err = bpf_mem_alloc_init(&htab->ma, htab->elem_size, BPF_MA_NO_REUSE,
htab_elem_ctor);
if (err)
goto free_map_locked;
if (percpu) {
err = bpf_mem_alloc_init(&htab->pcpu_ma,
round_up(htab->map.value_size, 8),
- BPF_MA_PERCPU, NULL);
+ BPF_MA_PERCPU | BPF_MA_NO_REUSE, NULL);
if (err)
goto free_map_locked;
}
--
2.29.2
