netdev - Re: [RFC PATCH] net: Introduce a socket option to enable picking tx queue based on rx queue.

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] [day] [month] [year] [list]

Date:   Wed, 20 Sep 2017 17:30:47 +0200
From:   Hannes Frederic Sowa <hannes@...essinduktion.org>
To:     Sridhar Samudrala <sridhar.samudrala@...el.com>
Cc:     alexander.h.duyck@...el.com, netdev@...r.kernel.org
Subject: Re: [RFC PATCH] net: Introduce a socket option to enable picking tx queue based on rx queue.

Sridhar Samudrala <sridhar.samudrala@...el.com> writes:

> This patch introduces a new socket option SO_SYMMETRIC_QUEUES that can be used
> to enable symmetric tx and rx queues on a socket.
>
> This option is specifically useful for epoll based multi threaded workloads
> where each thread handles packets received on a single RX queue . In this model,
> we have noticed that it helps to send the packets on the same TX queue
> corresponding to the queue-pair associated with the RX queue specifically when
> busy poll is enabled with epoll().
>
> Two new fields are added to struct sock_common to cache the last rx ifindex and
> the rx queue in the receive path of an SKB. __netdev_pick_tx() returns the cached
> rx queue when this option is enabled and the TX is happening on the same device.

Would it help to make the rx and tx skb hashes symmetric
(skb_get_hash_symmetric) on request?