netdev - Re: [RFC] [PATCH] net: Add support for ndo_select_queue() functions to cache the queue mapping

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: <20100128100011.2b624a9e@nehalam>
Date:	Thu, 28 Jan 2010 10:00:11 -0800
From:	Stephen Hemminger <shemminger@...tta.com>
To:	Ben Hutchings <bhutchings@...arflare.com>
Cc:	netdev@...r.kernel.org, linux-net-drivers@...arflare.com
Subject: Re: [RFC] [PATCH] net: Add support for ndo_select_queue() functions
 to cache the queue mapping

On Thu, 28 Jan 2010 17:38:37 +0000
Ben Hutchings <bhutchings@...arflare.com> wrote:

> We think it's worth matching up RX and TX queue selection for a socket
> when the queues share an interrupt.  Currently the default TX queue
> selection is unlikely to match RX queue selection.  TX queue selectionc
> can be overridden by the driver to match RX queue selection, but at the
> expense of caching.  We found that without caching the cost of
> recalculating the the hash in software for each packet outweighed the
> benefit of good queue selection.

Will this work with RPS and device driver hashing?
I am thinking of the problem where the hardware hash function is
Toeplitz (per NDIS spec), and the software hash function is Jhash
(what kernel uses because it is cheaper).

Therefore the transmit hash and receiver hash will be different.


-- 
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html