From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH 20/30] netvm: filter emergency skbs. Date: Thu, 20 Mar 2008 21:11:02 +0100 Message-ID: <20080320202124.436150000@chello.nl> References: <20080320201042.675090000@chello.nl> To: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, trond.myklebust@fy Return-path: Received: from viefep18-int.chello.at ([213.46.255.22]:63981 "EHLO viefep19-int.chello.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755896AbYCTUgm (ORCPT ); Thu, 20 Mar 2008 16:36:42 -0400 Content-Disposition: inline; filename=netvm-sk_filter.patch Sender: netdev-owner@vger.kernel.org List-ID: Toss all emergency packets not for a SOCK_MEMALLOC socket. This ensures our precious memory reserve doesn't get stuck waiting for user-space. The correctness of this approach relies on the fact that networks must be assumed lossy. Signed-off-by: Peter Zijlstra --- include/net/sock.h | 3 +++ 1 file changed, 3 insertions(+) Index: linux-2.6/include/net/sock.h =================================================================== --- linux-2.6.orig/include/net/sock.h +++ linux-2.6/include/net/sock.h @@ -1007,6 +1007,9 @@ static inline int sk_filter(struct sock { int err; struct sk_filter *filter; + + if (skb_emergency(skb) && !sk_has_memalloc(sk)) + return -ENOMEM; err = security_sock_rcv_skb(sk, skb); if (err) --