netdev - Re: [PATCH net-next] net/mlx5e: Transmit small messages in linear skb

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <82c14009-da71-4c2a-920c-7d32fcb1ffcb@nvidia.com>
Date: Tue, 10 Dec 2024 12:49:30 +0100
From: Dragos Tatulea <dtatulea@...dia.com>
To: Alexandra Winter <wintera@...ux.ibm.com>,
 Eric Dumazet <edumazet@...gle.com>
Cc: Rahul Rameshbabu <rrameshbabu@...dia.com>,
 Saeed Mahameed <saeedm@...dia.com>, Tariq Toukan <tariqt@...dia.com>,
 Leon Romanovsky <leon@...nel.org>, David Miller <davem@...emloft.net>,
 Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
 Andrew Lunn <andrew+netdev@...n.ch>, Nils Hoppmann <niho@...ux.ibm.com>,
 netdev@...r.kernel.org, linux-s390@...r.kernel.org,
 Heiko Carstens <hca@...ux.ibm.com>, Vasily Gorbik <gor@...ux.ibm.com>,
 Alexander Gordeev <agordeev@...ux.ibm.com>,
 Christian Borntraeger <borntraeger@...ux.ibm.com>,
 Sven Schnelle <svens@...ux.ibm.com>,
 Thorsten Winkler <twinkler@...ux.ibm.com>, Simon Horman <horms@...nel.org>
Subject: Re: [PATCH net-next] net/mlx5e: Transmit small messages in linear skb



On 06.12.24 16:25, Alexandra Winter wrote:
> 
> 
> On 04.12.24 15:36, Eric Dumazet wrote:
>> I would suggest the opposite : copy the headers (typically less than
>> 128 bytes) on a piece of coherent memory.
>>
>> As a bonus, if skb->len is smaller than 256 bytes, copy the whole skb.
>>
>> include/net/tso.h and net/core/tso.c users do this.
>>
>> Sure, patch is going to be more invasive, but all arches will win.
> 
> 
> Thank you very much for the examples, I think I understand what you are proposing.
> I am not sure whether I'm able to map it to the mlx5 driver, but I could
> try to come up with a RFC. It may take some time though.
> 
> NVidia people, any suggesttions? Do you want to handle that yourselves?
> 
Discussed with Saeed and he proposed another approach that is better for
us: copy the whole skb payload inline into the WQE if it's size is below a
threshold. This threshold can be configured through the
tx-copybreak mechanism.

Thanks,
Dragos