From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH] ipv4: Remove unnecessary code from rt_check_expire(). Date: Tue, 26 Jun 2012 09:39:58 +0200 Message-ID: <1340696398.10893.209.camel@edumazet-glaptop> References: <20120626.002124.2220875506847485306.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from mail-bk0-f46.google.com ([209.85.214.46]:48073 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753804Ab2FZHkD (ORCPT ); Tue, 26 Jun 2012 03:40:03 -0400 Received: by bkcji2 with SMTP id ji2so3874620bkc.19 for ; Tue, 26 Jun 2012 00:40:02 -0700 (PDT) In-Reply-To: <20120626.002124.2220875506847485306.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 2012-06-26 at 00:21 -0700, David Miller wrote: > IPv4 routing cache entries no longer use dst->expires, because the > metrics, PMTU, and redirect information are stored in the inetpeer > cache. > > Signed-off-by: David S. Miller > --- > > Eric, when you did commit 9f28a2fc0bd77511f649c0a788c7bf9a5fd04edb > (ipv4: reintroduce route cache garbage collector) do you remember > if the thing we needed was the real expiry or both the > rt_is_expired() and the rt_may_expire() cases? > > I really want to remove rt_may_expire() from this conditional because > it results in absolutely stupid behavior. If your system is idle > for 5 minutes, all of your input routing cache entries are purged. Hmm, after a DDOS, purging all those routing cache entries in 5 minutes is good to recover some Mbytes of kernel memory.