From: Robert Olsson <Robert.Olsson@data.slu.se>
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Message-ID: <17183.309.317160.103056@robur.slu.se>
Date: Wed, 7 Sep 2005 17:03:17 +0200
To: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Simon Kirby <sim@netnation.com>, Robert Olsson <Robert.Olsson@data.slu.se>,
        Eric Dumazet <dada1@cosmosbay.com>, netdev@oss.sgi.com
Subject: Re: Route cache performance
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Alexey Kuznetsov writes:

 > Robert, have you seen this pehonomenon already? Did you mean that SMP works
 > or that it never works (but this patch is valid only for UP)? Did it
 > become worse after 2.6.9?

 It was quite some time since I saw dst cache overflow and we use 2.6 
 in infrastructure. Anyway I was able to "tune" route cache so I see
 in our lab system on a SMP box. I think UP and SMP behaves the same 
 but with UP we could disable the deferred delete as Simon tested.

 I don't know if anything happen in 2.6.9 I don't think so. But any
 improvement in drivers or FIB lookup may increase the burden so we get
 overflows.

 We had some code that checked the RCU latency. 
  
 Cheers.
					--ro