From: Rick Jones <rick.jones2@hp.com>
To: Junchang Wang <junchangwang@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>,
romieu@fr.zoreil.com, netdev@vger.kernel.org
Subject: Re: Question about way that NICs deliver packets to the kernel
Date: Fri, 16 Jul 2010 10:58:46 -0700 [thread overview]
Message-ID: <4C409DD6.7060903@hp.com> (raw)
In-Reply-To: <AANLkTild5SQvt7Uw7AAV7BrrSdvPdoglgbm1uJQnigdM@mail.gmail.com>
Junchang Wang wrote:
>>You should also compare the CPU usage.
>>
>>Ben.
>>
>
> Hi Ben,
> I added options -c -C to netperf's command line. Result is as follows:
> scheme 1 scheme 2 Imp.
> Throughput: 683M 718M 5%
> CPU usage: 47.8% 45.6%
>
> That really surprised me because "top" command showed the CPU usage
> was fluctuating between 0.5% and 1.5% rather that between 45% and 50%.
Can you tell us a bit more about the system, and which version of netperf you
are using? Any chance that the CPU utilization you were looking at in top was
just that being charged to netperf the process? "Network processing" does not
often get charged to the responsible process, so netperf reports system-wide CPU
utilization on the assumption it is the only thing causing the CPUs to be utilized.
happy benchmarking,
rick jones
next prev parent reply other threads:[~2010-07-16 17:58 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-15 14:24 Question about way that NICs deliver packets to the kernel Junchang Wang
2010-07-15 14:33 ` Ben Hutchings
2010-07-15 15:59 ` Stephen Hemminger
2010-07-16 7:05 ` Junchang Wang
2010-07-16 17:58 ` Rick Jones [this message]
2010-07-20 1:15 ` Junchang Wang
2010-07-20 17:16 ` Rick Jones
2010-07-25 14:18 ` Junchang Wang
2010-07-15 21:12 ` Francois Romieu
2010-07-16 7:35 ` Junchang Wang
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