linux-kernel - Re: [PATCH net-next] hyperv: Add support for Virtual Receive Side Scaling (vRSS)

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:	Thu, 19 Dec 2013 22:05:44 +0000
From:	Ben Hutchings <bhutchings@...arflare.com>
To:	Tom Herbert <therbert@...gle.com>
CC:	Haiyang Zhang <haiyangz@...rosoft.com>,
	Daniel Borkmann <dborkman@...hat.com>,
	"davem@...emloft.net" <davem@...emloft.net>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	KY Srinivasan <kys@...rosoft.com>,
	"olaf@...fle.de" <olaf@...fle.de>,
	"jasowang@...hat.com" <jasowang@...hat.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"driverdev-devel@...uxdriverproject.org" 
	<driverdev-devel@...uxdriverproject.org>
Subject: Re: [PATCH net-next] hyperv: Add support for Virtual Receive Side
 Scaling (vRSS)

On Thu, 2013-12-19 at 13:43 -0800, Tom Herbert wrote:
> Patch is below. This version did most pre-computation of the variants
> I built, but results in largest table (40*256*4 bytes), This gives
> performance roughly comparable with jhash (roughly same as jhash for
> IPv4, about 30% more cycles for IPv6). I have the simpler less memory
> intensive versions also if you're interested, these are 10x worse
> cycles so I wouldn't want those in critical path.
> ----
> Introduce Toeplitz hash functions. Toeplitz is a hash used primarily in
> NICs to performan RSS flow steering.  This is a software implemenation
> of that. In order to make the hash calculation efficient, we precompute
> the possible hash values for each inidividual byte of input. The input
> length is up to 40 bytes, so we make an array of cache[40][256].
[...]

You haven't addressed my comments here:
<http://article.gmane.org/gmane.linux.network/284753>

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/