From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH 20/33] netvm: filter emergency skbs. Date: Tue, 30 Oct 2007 17:04:21 +0100 Message-ID: <20071030160914.329519000@chello.nl> References: <20071030160401.296770000@chello.nl> Cc: Peter Zijlstra To: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, trond.myklebust@fys.uio.no Return-path: Received: from mx1.redhat.com ([66.187.233.31]:47082 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756121AbXJ3QOP (ORCPT ); Tue, 30 Oct 2007 12:14:15 -0400 Content-Disposition: inline; filename=netvm-sk_filter.patch Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 @@ -930,6 +930,9 @@ 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) --