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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 13 Sep 2018 14:12:39 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     fw@...len.de
Cc:     linux@...m.de, netdev@...r.kernel.org,
        steffen.klassert@...unet.com, linux-kernel@...r.kernel.org,
        torvalds@...ux-foundation.org, christophe.gouault@...nd.com
Subject: Re: Regression: kernel 4.14 an later very slow with many ipsec
 tunnels

From: Florian Westphal <fw@...len.de>
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 :-)