Commit 001ce546 authored Dec 21, 2014 by Herbert Xu Committed by David S. Miller Dec 23, 2014

net: Detect drivers that reschedule NAPI and exhaust budget



The commit d75b1ade (net: less
interrupt masking in NAPI) required drivers to leave poll_list
empty if the entire budget is consumed.

We have already had two broken drivers so let's add a check for
this.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 726ce70e

net/core/dev.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -4602,6 +4602,15 @@ static int napi_poll(struct napi_struct n, struct list_head repoll)
		napi_gro_flush(n, HZ >= 1000);
		}

		/* Some drivers may have called napi_schedule
		* prior to exhausting their budget.
		*/
		if (unlikely(!list_empty(&n->poll_list))) {
		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
		n->dev ? n->dev->name : "backlog");
		goto out_unlock;
		}

		list_add_tail(&n->poll_list, repoll);

		out_unlock: