Messages in this thread |  | | From | Wolfgang Walter <> | Subject | Re: Regression: kernel 4.14 an later very slow with many ipsec tunnels | Date | Tue, 02 Oct 2018 16:45:56 +0200 |
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Hello,
Am Freitag, 14. September 2018, 07:54:37 schrieb Florian Westphal: > Steffen Klassert <steffen.klassert@secunet.com> wrote: > > On Thu, Sep 13, 2018 at 11:03:25PM +0200, Florian Westphal wrote: > > > 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 :/ > > > > 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")?
Since my last reply to this message I didn't get a reply: is there any progress how to fix this performance regression I missed?
Or are we stuck here with longterm kernel 4.9 for a long time?
Regards, -- Wolfgang Walter Studentenwerk München Anstalt des öffentlichen Rechts
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