From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Chua Subject: Re: iptables very slow after commit 784544739a25c30637397ace5489eeb6e15d7d49 Date: Sun, 12 Apr 2009 00:05:34 +0800 Message-ID: References: <20090410095246.4fdccb56@s6510> <20090410.182507.140306636.davem@davemloft.net> <20090411041533.GB6822@linux.vnet.ibm.com> <20090411080739.4cb77370@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Jan Engelhardt , "Paul E. McKenney" , Linus Torvalds , David Miller , Ingo Molnar , Lai Jiangshan , dada1@cosmosbay.com, kaber@trash.net, r000n@r000n.net, Linux Kernel Mailing List , netfilter-devel@vger.kernel.org, netdev@vger.kernel.org To: Stephen Hemminger Return-path: Received: from wf-out-1314.google.com ([209.85.200.171]:61126 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754967AbZDKQFf convert rfc822-to-8bit (ORCPT ); Sat, 11 Apr 2009 12:05:35 -0400 In-Reply-To: <20090411080739.4cb77370@nehalam> Sender: netfilter-devel-owner@vger.kernel.org List-ID: On Sat, Apr 11, 2009 at 11:07 PM, Stephen Hemminger wrote: >> iptables works in whole tables. Userspace submits a table, checkentr= y is >> called for all rules in the new table, things are swapped, then dest= roy >> is called for all rules in the old table. By that logic (which exist= ed >> since dawn I think), only the swap operation needs to be locked. > Part of the overhead is the API choice to take counter values from us= er > space during the replace. =A0If the rule replacement just always star= ted with > zero counters it could be done with less overhead. It's always good practice to start from zero with these ... # iptables -F # iptables -t nat -F # iptables -X And most of the time, rules should be put into a file so that it can rerun easily after reboot. So if it can be speed up for just this case, it'll help many out there. Thanks, Jeff. -- To unsubscribe from this list: send the line "unsubscribe netfilter-dev= el" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html