netdev - Re: [PATCH net-next] vlan: use ether_addr_equal_64bits to instead of ether_addr

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:	Sun, 02 Mar 2014 17:37:42 -0800
From:	Joe Perches <joe@...ches.com>
To:	Ding Tianhong <dingtianhong@...wei.com>
Cc:	Patrick McHardy <kaber@...sh.net>,
	"David S. Miller" <davem@...emloft.net>,
	Julia Lawall <julia.lawall@...6.fr>,
	Netdev <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next] vlan: use ether_addr_equal_64bits to instead
 of ether_addr_equal

On Mon, 2014-03-03 at 09:14 +0800, Ding Tianhong wrote:
> Ether_addr_equal_64bits is more efficient than ether_addr_equal, and
> can be used when each argument is an array within a structure that
> contains at least two bytes of data beyond the array, so it is safe
> to use it for vlan.

It's true that ether_addr_equal_64bits is faster for
64 bit architectures.  It's 1 64 bit compare and 1 
48 bit mask instead of a 32 bit and a 16 bit compare.

I think unless the code is _extremely_ performance or
fast-path sensitive, ether_addr_equal should be used.

I believe the vlan_do_receive use qualifies.

Are any of the others on the fast path?

Do you have any performance numbers?

--
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