linux-kernel - Re: [PATCH v2 net] splice: do not checksum AF

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: <Z1hsPdG3ITuDlWnT@LQ3V64L9R2>
Date: Tue, 10 Dec 2024 08:28:45 -0800
From: Joe Damato <jdamato@...tly.com>
To: Frederik Deweerdt <deweerdt.lkml@...il.com>
Cc: netdev@...r.kernel.org, "David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Simon Horman <horms@...nel.org>,
	Kuniyuki Iwashima <kuniyu@...zon.com>, Michal Luczaj <mhal@...x.co>,
	David Howells <dhowells@...hat.com>, linux-kernel@...r.kernel.org,
	xiyou.wangcong@...il.com, David.Laight@...lab.com,
	stable@...r.kernel.org
Subject: Re: [PATCH v2 net] splice: do not checksum AF_UNIX sockets

On Mon, Dec 09, 2024 at 09:06:48PM -0800, Frederik Deweerdt wrote:
> When `skb_splice_from_iter` was introduced, it inadvertently added
> checksumming for AF_UNIX sockets. This resulted in significant
> slowdowns, for example when using sendfile over unix sockets.
> 
> Using the test code in [1] in my test setup (2G single core qemu),
> the client receives a 1000M file in:
> - without the patch: 1482ms (+/- 36ms)
> - with the patch: 652.5ms (+/- 22.9ms)
> 
> This commit addresses the issue by marking checksumming as unnecessary in
> `unix_stream_sendmsg`
> 
> Cc: stable@...r.kernel.org
> Signed-off-by: Frederik Deweerdt <deweerdt.lkml@...il.com>
> Fixes: 2e910b95329c ("net: Add a function to splice pages into an skbuff for MSG_SPLICE_PAGES")
> ---
>  net/unix/af_unix.c | 1 +
>  1 file changed, 1 insertion(+)

Reviewed-by: Joe Damato <jdamato@...tly.com>