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From: Stephen Hemminger <stephen@networkplumber.org>
To: "平岡 冠二" <hiraoka737@oki.com>
Cc: "users@dpdk.org" <users@dpdk.org>
Subject: Re: [dpdk-users] how can i know the reason why the rx_nombuf couner increase?
Date: Tue, 8 Sep 2020 08:43:48 -0700	[thread overview]
Message-ID: <20200908084348.1e8fccd5@hermes.lan> (raw)
In-Reply-To: <TY2PR01MB33226DB8301AAA73A4F3BE179C290@TY2PR01MB3322.jpnprd01.prod.outlook.com>

On Tue, 8 Sep 2020 07:40:58 +0000
"平岡 冠二" <hiraoka737@oki.com> wrote:

> Hi All,
> 
> This is my first post here. I've an issue, and I would like your help.
> 
> HW Environment:
>  HP DL360 Gen10 (Xeon Silver 4208 @ 2.1GHz)
>  HPE Ethernet 10Gb 2Port NIC 562T (Intel X550T, driver=5.1.0-k-rh7.6, firmware=10.51.3)
> 
> SW Environment:
>  DPDK 20.08
>  Red Hat Enterprise Linux Server release 7.6 (Maipo)
>  Number of mbuf is 1024 * 1024 (plenty!)
> 
> I create the packet capture with DPDK 20.08 and received 1.2Gbps(1Mfps) packets on my 
> server described above, but, rarely(about once per 100 hours) encountered the packet loss
> problem.
> 
> To find the reason, I use the rte_eth_stats_get() and found imissed and rx_nombuf counter 
> was increased when packet loss was happened.
> 
> Is this means that the CPU power was insufficient? or my application rarely slow down? or
> none of them?  Does anyone know how can I know that?

The counter imissed means the application can not keep up with the packet rate.
The counter rx_nombuf means the mbuf pool was not big enough (or your application is
leaking mbufs).

> on a side note...
> 
> When I wrote the captured packet to SSD drive, rarely packet loss was happen, but, 
> when I wrote them to SAS HDD drive (it is slower than SSD) the packet loss was not 
> occurred(at least one week). it was very mysterious...

Not at all surprising, packet capture is limited by speed of writing to file.

      reply	other threads:[~2020-09-08 15:43 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-08  7:40 平岡 冠二
2020-09-08 15:43 ` Stephen Hemminger [this message]

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