From: fengchengwen <fengchengwen@huawei.com>
To: Stephen Hemminger <stephen@networkplumber.org>,
Dpdk Newbie <dpdkuser77@gmail.com>
Cc: <dev@dpdk.org>
Subject: Re: Does DPDK provide RX timestamps?
Date: Mon, 9 Sep 2024 16:23:57 +0800 [thread overview]
Message-ID: <bff3557c-1712-bda8-4814-04ebedef7c9b@huawei.com> (raw)
In-Reply-To: <20240908171355.264071b2@hermes.local>
On 2024/9/9 8:13, Stephen Hemminger wrote:
> On Sun, 8 Sep 2024 23:31:36 +0100
> Dpdk Newbie <dpdkuser77@gmail.com> wrote:
>
>> Hi. I am using Intel (i210) and AWS ENA network interface cards.
>>
>> I would like to measure the following RX latencies:
>>
>> 1) NIC to DPDK packet ring buffer
>> 2) DPDK packet ring buffer to application via rte_eth_rx_burst.
Some packet generator support delay measurement, could construct two tests:
1. run with enabled hairpin
some NIC support hairpin (the data write to memory and resend by hardware again)
if the NIC don't support hairpin, could use mac outer loop.
2. run with normal mode
According compare the two delay.
>>
>> I don't mind measuring in nanoseconds or CPU cycles.
>>
>> Unfortunately I cannot find any mention of hardware timestamps.
>>
>> I found brief references to mbuf containing a timestamp in the dynamic
>> fields, but nothing definitive.
>>
>> Could someone please clarify what the situation is?
>>
>> Thanks,
>
> Depends on the hardware, and the dynamic field for rx timestamp
As I know, this Rx timestamp dynamic field is mainly used by PTP(IEEE1588).
> also varies in its clock value. Some are ticks, some are us, some are ns;
> and the base is arbitrary so difficult to use for packet capture.
Yes
> .
>
next prev parent reply other threads:[~2024-09-09 8:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-08 22:31 Dpdk Newbie
2024-09-09 0:13 ` Stephen Hemminger
2024-09-09 8:23 ` fengchengwen [this message]
[not found] ` <8a180c35-c4fd-4760-a4fa-f7d3ff360fab@email.android.com>
[not found] ` <40e44bc0f788441ea70f48a33bef7f59@amazon.com>
2024-09-09 8:31 ` Brandes, Shai
2024-09-09 17:54 ` Dpdk Newbie
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=bff3557c-1712-bda8-4814-04ebedef7c9b@huawei.com \
--to=fengchengwen@huawei.com \
--cc=dev@dpdk.org \
--cc=dpdkuser77@gmail.com \
--cc=stephen@networkplumber.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).