Re: Regression: kernel 4.14 an later very slow with many ipsec tunnels

[David Miller]

From: Florian Westphal <fw@xxxxxxxxx>
Date: Thu, 13 Sep 2018 23:03:25 +0200

> 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.

The inexact list exists to handle prefixed input keys.

At the time that I wrote all of the control plane hash table
stuff, configurations I could find consisted of:

1) Entires with non-prefixed keys, which are easy to hash.
   The number of entries could be large (e.g. cell phone
   network)

2) A very small number of prefixed policies.

So hashing, when possible, falling back to the linked list
for prefixed stuff.

Beforehand we only had the linked list :-)