* [PATCH bpf-next] bpf: no longer acquire map_idr_lock in bpf_map_inc_not_zero()
@ 2025-03-01 19:13 Eric Dumazet
2025-03-02 0:05 ` Stanislav Fomichev
2025-03-03 2:30 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Eric Dumazet @ 2025-03-01 19:13 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, John Fastabend
Cc: Stanislav Fomichev, netdev, bpf, eric.dumazet, Eric Dumazet,
Kui-Feng Lee, Martin KaFai Lau
bpf_sk_storage_clone() is the only caller of bpf_map_inc_not_zero()
and is holding rcu_read_lock().
map_idr_lock does not add any protection, just remove the cost
for passive TCP flows.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kui-Feng Lee <kuifeng@meta.com>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
---
kernel/bpf/syscall.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index e1e42e918ba7f682223e9a78028bb0cc360c01ce..d68c8d61f7ceddb732a5646c00b8f0c71fdc2d71 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1593,11 +1593,8 @@ struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
{
- spin_lock_bh(&map_idr_lock);
- map = __bpf_map_inc_not_zero(map, false);
- spin_unlock_bh(&map_idr_lock);
-
- return map;
+ lockdep_assert(rcu_read_lock_held());
+ return __bpf_map_inc_not_zero(map, false);
}
EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
--
2.48.1.711.g2feabab25a-goog
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH bpf-next] bpf: no longer acquire map_idr_lock in bpf_map_inc_not_zero()
2025-03-01 19:13 [PATCH bpf-next] bpf: no longer acquire map_idr_lock in bpf_map_inc_not_zero() Eric Dumazet
@ 2025-03-02 0:05 ` Stanislav Fomichev
2025-03-03 2:30 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: Stanislav Fomichev @ 2025-03-02 0:05 UTC (permalink / raw)
To: Eric Dumazet
Cc: Alexei Starovoitov, Daniel Borkmann, John Fastabend,
Stanislav Fomichev, netdev, bpf, eric.dumazet, Kui-Feng Lee,
Martin KaFai Lau
On 03/01, Eric Dumazet wrote:
> bpf_sk_storage_clone() is the only caller of bpf_map_inc_not_zero()
> and is holding rcu_read_lock().
>
> map_idr_lock does not add any protection, just remove the cost
> for passive TCP flows.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH bpf-next] bpf: no longer acquire map_idr_lock in bpf_map_inc_not_zero()
2025-03-01 19:13 [PATCH bpf-next] bpf: no longer acquire map_idr_lock in bpf_map_inc_not_zero() Eric Dumazet
2025-03-02 0:05 ` Stanislav Fomichev
@ 2025-03-03 2:30 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2025-03-03 2:30 UTC (permalink / raw)
To: Eric Dumazet
Cc: ast, daniel, john.fastabend, sdf, netdev, bpf, eric.dumazet,
kuifeng, martin.lau
Hello:
This patch was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:
On Sat, 1 Mar 2025 19:13:15 +0000 you wrote:
> bpf_sk_storage_clone() is the only caller of bpf_map_inc_not_zero()
> and is holding rcu_read_lock().
>
> map_idr_lock does not add any protection, just remove the cost
> for passive TCP flows.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Kui-Feng Lee <kuifeng@meta.com>
> Cc: Martin KaFai Lau <martin.lau@kernel.org>
>
> [...]
Here is the summary with links:
- [bpf-next] bpf: no longer acquire map_idr_lock in bpf_map_inc_not_zero()
https://git.kernel.org/bpf/bpf-next/c/17a82ed98f62
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 3+ messages in thread
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2025-03-01 19:13 [PATCH bpf-next] bpf: no longer acquire map_idr_lock in bpf_map_inc_not_zero() Eric Dumazet
2025-03-02 0:05 ` Stanislav Fomichev
2025-03-03 2:30 ` patchwork-bot+netdevbpf
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