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From: Florian Westphal <fw@strlen.de>
To: David Miller <davem@davemloft.net>
Cc: fw@strlen.de, linux@stwm.de, netdev@vger.kernel.org,
	steffen.klassert@secunet.com, 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
Date: Thu, 13 Sep 2018 23:03:25 +0200	[thread overview]
Message-ID: <20180913210325.5usfj2rorvuvtyc7@breakpoint.cc> (raw)
In-Reply-To: <20180913.102305.939671149040995911.davem@davemloft.net>

David Miller <davem@davemloft.net> wrote:
> From: Florian Westphal <fw@strlen.de>
> Date: Thu, 13 Sep 2018 18:38:48 +0200
> 
> > Wolfgang Walter <linux@stwm.de> 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 :/

I'll look at this again tomorrow.

  reply	other threads:[~2018-09-13 21:03 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-13 11:30 Regression: kernel 4.14 an later very slow with many ipsec tunnels Wolfgang Walter
2018-09-13 13:58 ` Florian Westphal
2018-09-13 15:46   ` Wolfgang Walter
2018-09-13 16:38     ` Florian Westphal
2018-09-13 17:23       ` David Miller
2018-09-13 21:03         ` Florian Westphal [this message]
2018-09-13 21:12           ` David Miller
2018-09-14  5:06           ` Steffen Klassert
2018-09-14  5:54             ` Florian Westphal
2018-09-14  6:01               ` Steffen Klassert
2018-09-14  8:01                 ` Christophe Gouault
2018-09-14 11:49               ` Wolfgang Walter
2018-10-02 14:45               ` Wolfgang Walter
2018-10-02 14:56                 ` Florian Westphal
2018-10-02 17:34                   ` Wolfgang Walter
2018-10-02 21:35                     ` Florian Westphal
2018-10-04 13:57                       ` Wolfgang Walter
2018-10-25  9:38                         ` Wolfgang Walter
2018-10-25 17:34                           ` David Miller
2018-10-25 19:24                             ` Florian Westphal
2018-10-26 12:18                             ` Wolfgang Walter
2018-10-25 22:45                           ` Florian Westphal

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