From: David Miller <davem@davemloft.net>
To: therbert@google.com
Cc: netdev@vger.kernel.org
Subject: Re: state of rtcache removal...
Date: Wed, 16 Feb 2011 19:27:51 -0800 (PST) [thread overview]
Message-ID: <20110216.192751.104051014.davem@davemloft.net> (raw)
In-Reply-To: <AANLkTi=W=1ZiP4JOJwo=FccNA9aK=1bpRn=zkepXXMzi@mail.gmail.com>
From: Tom Herbert <therbert@google.com>
Date: Wed, 16 Feb 2011 18:59:35 -0800
> On Wed, Feb 16, 2011 at 4:08 PM, David Miller <davem@davemloft.net> wrote:
>>
>> So I've been testing out the routing cache removal patch to see
>> what the impact is on performance.
>>
> Interesting results.
>
> I assume that this test is purposely using sento on a connected socket
> to force sendmsg to go through the route lookup :-), so this is
> showing what the benefits of rtcache are is when cache hit rate is
> 100%. For comparison, it might interesting to see what the
> performance is when rate is < 100%. For instance, we often see hit
> rates < 20% on front end servers. This could be done flooding to
> random addresses in 10/8 or even 0/0... I'm hoping that without the
> rtcache performance actually improves in that case!
We know that the performance will be higher in the "closer to %0"
situation, ie. for DoS workloads. Because all of the route cache
management overhead goes away.
Anyways I'm working on some ideas to make the high hit rate case
perform amicably again.
next prev parent reply other threads:[~2011-02-17 3:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-17 0:08 state of rtcache removal David Miller
2011-02-17 2:59 ` Tom Herbert
2011-02-17 3:27 ` David Miller [this message]
2011-02-17 6:25 ` Eric Dumazet
2011-02-17 6:39 ` David Miller
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