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From: "Chris Friesen" <cfriesen@nortel.com>
To: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Subject: Re: questions on NAPI processing latency and dropped network packets
Date: Mon, 21 Jan 2008 13:53:44 -0600	[thread overview]
Message-ID: <4794F848.9020402@nortel.com> (raw)
In-Reply-To: <478654C3.60806@nortel.com>

I've done some further digging, and it appears that one of the problems 
we may be facing is very high instantaneous traffic rates.

Instrumentation showed up to 222K packets/sec for short periods (at 
least 1.1 ms, possibly longer), although the long-term average is down 
around 14-16K packets/sec.

If I bump the rx ring size up to 4096, we can handle all the packets and 
we still have 44% idle on cpu0 and 27% idle on cpu1.

Is there anything else we can do to minimize the latency of network 
packet processing and avoid having to crank the rx ring size up so high?

Thanks,

Chris

  parent reply	other threads:[~2008-01-21 19:53 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-10 17:24 questions on NAPI processing latency and dropped network packets Chris Friesen
2008-01-10 17:37 ` Kok, Auke
2008-01-10 18:12   ` Chris Friesen
2008-01-10 18:26     ` Kok, Auke
2008-01-10 18:25 ` James Chapman
2008-01-10 21:29   ` Chris Friesen
2008-01-10 18:41 ` Rick Jones
2008-01-10 19:01   ` Kok, Auke
2008-01-11  1:20 ` David Miller
2008-01-11 14:59   ` Chris Friesen
2008-01-11 22:29     ` Herbert Xu
2008-01-12  1:53     ` David Miller
2008-01-14 15:58       ` Chris Friesen
2008-01-15  7:19         ` Jarek Poplawski
2008-01-15 14:47           ` Chris Friesen
2008-01-15 15:17             ` Radoslaw Szkodzinski
2008-01-15 17:14               ` Chris Friesen
2008-01-15 17:23                 ` Eric Dumazet
2008-01-15 20:29             ` Jarek Poplawski
2008-01-16  0:17               ` Herbert Xu
2008-01-16  6:58                 ` Jarek Poplawski
2008-01-16 20:04                   ` Willy Tarreau
2008-01-16 22:42                     ` Jarek Poplawski
2008-01-12  5:37 ` Ray Lee
2008-01-14 15:49   ` Chris Friesen
2008-01-14 16:56     ` Eric Dumazet
2008-01-14 19:25       ` Chris Friesen
2008-01-14 19:33         ` Eric Dumazet
2008-01-14 20:02           ` Chris Friesen
2008-01-15 15:09             ` Vlad Yasevich
2008-01-21 19:53 ` Chris Friesen [this message]
2008-01-21 21:11   ` Ben Greear
2008-01-21 23:15     ` Chris Friesen
2008-01-21 23:32       ` Ben Greear
2008-01-21 21:31   ` Eric Dumazet
2008-01-21 23:25     ` Chris Friesen
2008-01-22  5:46       ` Eric Dumazet

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