From: Olivier Matz <olivier.matz@6wind.com>
To: "Morten Brørup" <mb@smartsharesystems.com>, dev@dpdk.org
Subject: Re: [dpdk-dev] mbuf changes
Date: Tue, 25 Oct 2016 15:14:06 +0200 [thread overview]
Message-ID: <1fb6b9cd-341c-1aaa-6a9f-56b758af772e@6wind.com> (raw)
In-Reply-To: <98CBD80474FA8B44BF855DF32C47DC359EA8B1@smartserver.smartshare.dk>
Hi,
On 10/24/2016 05:49 PM, Morten Brørup wrote:
> And here’s something new to think about:
>
> m->next already reveals if there are more segments to a packet. Which
> purpose does m->nb_segs serve that is not already covered by m->next?
>
I was asking myself the same question some time ago:
http://dpdk.org/ml/archives/dev/2016-May/039483.html
But it seems nb_segs is useful for PMDs on TX side, to
anticipate how many descriptors a packet will use in the
TX ring. It can also help a PMD to check that this packet
is supported by the hardware (too many segments) without
browsing the list.
So finally I think it should be kept in the mbuf. But as
suggested by Bruce, it could go in the second cache line,
since m->next is also there, at the condition that this
field is set to 1 in mbuf_free().
Regards,
Olivier
next prev parent reply other threads:[~2016-10-25 13:14 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-24 15:49 Morten Brørup
2016-10-24 16:11 ` Wiles, Keith
2016-10-24 16:25 ` Bruce Richardson
2016-10-24 21:47 ` Morten Brørup
2016-10-25 8:53 ` Bruce Richardson
2016-10-25 10:02 ` Ananyev, Konstantin
2016-10-25 10:22 ` Morten Brørup
2016-10-25 13:00 ` Olivier Matz
2016-10-25 13:04 ` Ramia, Kannan Babu
2016-10-25 13:24 ` Thomas Monjalon
2016-10-25 14:32 ` Ramia, Kannan Babu
2016-10-25 14:54 ` Thomas Monjalon
2016-10-25 13:15 ` Bruce Richardson
2016-10-25 13:20 ` Thomas Monjalon
2016-10-25 9:39 ` Adrien Mazarguil
2016-10-25 10:11 ` Morten Brørup
2016-10-25 11:04 ` Adrien Mazarguil
2016-10-25 11:13 ` Bruce Richardson
2016-10-25 12:16 ` Morten Brørup
2016-10-25 12:20 ` Bruce Richardson
2016-10-25 12:33 ` Morten Brørup
2016-10-25 12:45 ` Bruce Richardson
2016-10-25 12:48 ` Olivier Matz
2016-10-25 13:13 ` Morten Brørup
2016-10-25 13:38 ` Ananyev, Konstantin
2016-10-25 14:25 ` Morten Brørup
2016-10-25 14:45 ` Olivier Matz
2016-10-28 13:34 ` Pattan, Reshma
2016-10-28 14:11 ` Morten Brørup
2016-10-28 15:25 ` Pattan, Reshma
2016-10-28 16:50 ` Adrien Mazarguil
2016-10-28 17:00 ` Richardson, Bruce
2016-10-28 20:27 ` Morten Brørup
2016-10-31 10:55 ` Morten Brørup
2016-10-31 16:05 ` Morten Brørup
2016-10-25 13:48 ` Adrien Mazarguil
2016-10-25 13:58 ` Ananyev, Konstantin
2016-10-25 11:54 ` Shreyansh Jain
2016-10-25 12:05 ` Bruce Richardson
2016-10-26 8:28 ` Alejandro Lucero
2016-10-26 9:01 ` Morten Brørup
2016-11-09 11:42 ` Alejandro Lucero
2016-11-10 9:19 ` [dpdk-dev] Fwd: " Alejandro Lucero
2016-10-25 12:49 ` [dpdk-dev] " Morten Brørup
2016-10-25 13:14 ` Olivier Matz [this message]
2016-10-25 13:18 ` Morten Brørup
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