From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH 18/29] netvm: filter emergency skbs. Date: Fri, 14 Dec 2007 16:39:25 +0100 Message-ID: <20071214154441.605741000@chello.nl> References: <20071214153907.770251000@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 bombadil.infradead.org ([18.85.46.34]:47259 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755099AbXLNTXh (ORCPT ); Fri, 14 Dec 2007 14:23:37 -0500 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 @@ -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) --