On 2020-11-12 15:36, Eric Dumazet wrote:
On Thu, Nov 12, 2020 at 12:41 PM Björn Töpel <bjorn.topel@xxxxxxxxx> wrote:
From: Björn Töpel <bjorn.topel@xxxxxxxxx>
This option lets a user set a per socket NAPI budget for
busy-polling. If the options is not set, it will use the default of 8.
Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx>
---
...
#else /* CONFIG_NET_RX_BUSY_POLL */
static inline unsigned long net_busy_loop_on(void)
@@ -106,7 +108,8 @@ static inline void sk_busy_loop(struct sock *sk, int nonblock)
if (napi_id >= MIN_NAPI_ID)
napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk,
- READ_ONCE(sk->sk_prefer_busy_poll));
+ READ_ONCE(sk->sk_prefer_busy_poll),
+ sk->sk_busy_poll_budget ?: BUSY_POLL_BUDGET);
Please use :
READ_ONCE(sk->sk_busy_poll_budget) ?: BUSY_POLL_BUDGET
Because sk_busy_loop() is usually called without socket lock being held.
This will prevent yet another KCSAN report.
#endif
}
...
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1165,6 +1165,16 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
else
sk->sk_prefer_busy_poll = valbool;
break;
+ case SO_BUSY_POLL_BUDGET:
+ if (val > sk->sk_busy_poll_budget && !capable(CAP_NET_ADMIN)) {
+ ret = -EPERM;
+ } else {
+ if (val < 0)
if (val < 0 || val > (u16)~0)
+ ret = -EINVAL;
+ else
+ sk->sk_busy_poll_budget = val;
WRITE_ONCE(sk->sk_busy_poll_budget, val);
Thanks for the review! I'll address it all.
