From: Herbert Xu Date: Sat, 20 Dec 2014 20:16:24 +0000 (+1100) Subject: net: Always poll at least one device in net_rx_action X-Git-Tag: v4.14-rc1~6196^2~18 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6bd373ebbac4b13ecd39ddc37a0dc5ad4c5e4585;p=platform%2Fkernel%2Flinux-rpi.git net: Always poll at least one device in net_rx_action We should only perform the softnet_break check after we have polled at least one device in net_rx_action. Otherwise a zero or negative setting of netdev_budget can lock up the whole system. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- diff --git a/net/core/dev.c b/net/core/dev.c index c0cf129..b85eba9 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4634,16 +4634,15 @@ static void net_rx_action(struct softirq_action *h) while (!list_empty(&list)) { struct napi_struct *n; + n = list_first_entry(&list, struct napi_struct, poll_list); + budget -= napi_poll(n, &repoll); + /* If softirq window is exhausted then punt. * Allow this to run for 2 jiffies since which will allow * an average latency of 1.5/HZ. */ if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit))) goto softnet_break; - - - n = list_first_entry(&list, struct napi_struct, poll_list); - budget -= napi_poll(n, &repoll); } if (!sd_has_rps_ipi_waiting(sd) &&