From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5D1FFC6182 for ; Fri, 14 Sep 2018 05:54:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 71DF320853 for ; Fri, 14 Sep 2018 05:54:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 71DF320853 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727391AbeINLHe (ORCPT ); Fri, 14 Sep 2018 07:07:34 -0400 Received: from Chamillionaire.breakpoint.cc ([146.0.238.67]:37948 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726822AbeINLHe (ORCPT ); Fri, 14 Sep 2018 07:07:34 -0400 Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.89) (envelope-from ) id 1g0h3t-00048m-7s; Fri, 14 Sep 2018 07:54:37 +0200 Date: Fri, 14 Sep 2018 07:54:37 +0200 From: Florian Westphal To: Steffen Klassert Cc: Florian Westphal , David Miller , linux@stwm.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, christophe.gouault@6wind.com Subject: Re: Regression: kernel 4.14 an later very slow with many ipsec tunnels Message-ID: <20180914055437.77pffp2jrbfnykbp@breakpoint.cc> References: <20180913135844.3ut6fxgx67t6ndtu@breakpoint.cc> <3448099.9yk84El3Sa@stwm.de> <20180913163848.ni5xc4gc4d6uusdn@breakpoint.cc> <20180913.102305.939671149040995911.davem@davemloft.net> <20180913210325.5usfj2rorvuvtyc7@breakpoint.cc> <20180914050651.GD23674@gauss3.secunet.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180914050651.GD23674@gauss3.secunet.de> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Steffen Klassert wrote: > On Thu, Sep 13, 2018 at 11:03:25PM +0200, Florian Westphal wrote: > > David Miller wrote: > > > From: Florian Westphal > > > Date: Thu, 13 Sep 2018 18:38:48 +0200 > > > > > > > Wolfgang Walter wrote: > > > >> What I can say is that it depends mainly on number of policy rules and SA. > > > > > > > > Thats already a good hint, I guess we're hitting long hash chains in > > > > xfrm_policy_lookup_bytype(). > > > > > > I don't really see how recent changes can influence that. > > > > I don't think there is a recent change that did this. > > > > Walter says < 4.14 is ok, so this is likely related to flow cache removal. > > > > F.e. it looks like all prefixed policies end up in a linked list > > (net->xfrm.policy_inexact) and are not even in a hash table. > > > > I am staring at b58555f1767c9f4e330fcf168e4e753d2d9196e0 > > but can't figure out how to configure that away from the > > 'no hashing for prefixed policies' default or why we even have > > policy_inexact in first place :/ > > The hash threshold can be configured like this: > > ip x p set hthresh4 0 0 > > This sets the hash threshold to local /0 and remote /0 netmasks. > With this configuration, all policies should go to the hashtable. Yes, but won't they all be hashed to same bucket? [ jhash(addr & 0, addr & 0) ] ? > Default hash thresholds are local /32 and remote /32 netmasks, so > all prefixed policies go to the inexact list. Yes. Wolfgang, before having to work on getting perf into your router image can you perhaps share a bit of info about the policies you're using? How many are there? Are they prefixed or not ("10.1.2.1")?