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 <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2014-12-21 07:16:24 +11:00 committed by David S. Miller
parent 001ce546bb
commit 6bd373ebba
1 changed files with 3 additions and 4 deletions

View File

@ -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) &&