netdev - Re: [PATCH v1 net-next 5/5] tcp: reorganize tcp

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]

Date: Fri, 15 Sep 2023 21:17:24 -0600
From: David Ahern <dsahern@...nel.org>
To: Coco Li <lixiaoyan@...gle.com>, Jakub Kicinski <kuba@...nel.org>,
 Eric Dumazet <edumazet@...gle.com>, Neal Cardwell <ncardwell@...gle.com>,
 Mubashir Adnan Qureshi <mubashirq@...gle.com>,
 Paolo Abeni <pabeni@...hat.com>
Cc: netdev@...r.kernel.org, Chao Wu <wwchao@...gle.com>,
 Wei Wang <weiwan@...gle.com>
Subject: Re: [PATCH v1 net-next 5/5] tcp: reorganize tcp_sock fast path
 variables

On 9/15/23 7:06 PM, Coco Li wrote:
> The variables are organized according to the following way:
> 
> - TX read-mostly hotpath cache lines
> - TXRX read-mostly hotpath cache lines
> - RX read-mostly hotpath cache lines
> - TX read-write hotpath cache line
> - TXRX read-write hotpath cache line
> - RX read-write hotpath cache line
> 
> Fastpath cachelines end after rcvq_space.
> 
> Cache line boundaries are enfored only between read-mostly and
> read-write. That is, if read-mostly tx cachelines bleed into 
> read-mostly txrx cachelines, we do not care. We care about the
> boundaries between read and write cachelines because we want
> to prevent false sharing.
> 
> Fast path variables span cache lines before change: 12
> Fast path variables span cache lines after change: 8
> 
> Tested:
> Built and installed.
> 
> Signed-off-by: Coco Li <lixiaoyan@...gle.com>
> Suggested-by: Eric Dumazet <edumazet@...gle.com>
> Reviewed-by: Wei Wang <weiwan@...gle.com>
> ---
>  include/linux/tcp.h | 233 ++++++++++++++++++++++----------------------
>  1 file changed, 119 insertions(+), 114 deletions(-)
> 

Reviewed-by: David Ahern <dsahern@...nel.org>