From: "Wiles, Keith" <keith.wiles@intel.com>
To: Saber Rezvani <irsaber@zoho.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>,
"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] IXGBE throughput loss with 4+ cores
Date: Tue, 28 Aug 2018 19:09:15 +0000 [thread overview]
Message-ID: <CC7A1A46-ED26-415E-AB52-BEA9AAEBBD7A@intel.com> (raw)
In-Reply-To: <ce7462f4-a4f5-3a8f-1817-2604f225546a@zoho.com>
Which version of Pktgen? I just pushed a patch in 3.5.3 to fix a performance problem.
> On Aug 28, 2018, at 12:05 PM, Saber Rezvani <irsaber@zoho.com> wrote:
>
>
>
> On 08/28/2018 08:31 PM, Stephen Hemminger wrote:
>> On Tue, 28 Aug 2018 17:34:27 +0430
>> Saber Rezvani <irsaber@zoho.com> wrote:
>>
>>> Hi,
>>>
>>>
>>> I have run multi_process/symmetric_mp example in DPDK example directory.
>>> For a one process its throughput is line rate but as I increase the
>>> number of cores I see decrease in throughput. For example, If the number
>>> of queues set to 4 and each queue assigns to a single core, then the
>>> throughput will be something about 9.4. if 8 queues, then throughput
>>> will be 8.5.
>>>
>>> I have read the following, but it was not convincing.
>>>
>>> http://mails.dpdk.org/archives/dev/2015-October/024960.html
>>>
>>>
>>> I am eagerly looking forward to hearing from you, all.
>>>
>>>
>>> Best wishes,
>>>
>>> Saber
>>>
>>>
>> Not completely surprising. If you have more cores than packet line rate
>> then the number of packets returned for each call to rx_burst will be less.
>> With large number of cores, most of the time will be spent doing reads of
>> PCI registers for no packets!
> Indeed pktgen says it is generating traffic at line rate, but receiving less than 10 Gb/s. So, it that case there should be something that causes the reduction in throughput :(
>
>
Regards,
Keith
next prev parent reply other threads:[~2018-08-28 19:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-28 13:04 Saber Rezvani
2018-08-28 16:01 ` Stephen Hemminger
2018-08-28 17:05 ` Saber Rezvani
2018-08-28 19:09 ` Wiles, Keith [this message]
2018-08-28 19:16 ` Saber Rezvani
2018-08-28 21:09 ` Wiles, Keith
2018-08-29 17:19 ` Saber Rezvani
2018-08-29 18:52 ` Wiles, Keith
2018-08-30 4:08 ` Saber Rezvani
2018-09-06 6:10 Saber Rezvani
2018-09-06 17:48 ` Wiles, Keith
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