netdev - Re: [PATCH 0/3 net-next] Bring sizeof(net

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, 10 Apr 2015 09:41:34 +0100
From:	Thomas Graf <tgraf@...g.ch>
To:	Alexei Starovoitov <alexei.starovoitov@...il.com>
Cc:	davem@...emloft.net, jeffrey.t.kirsher@...el.com,
	intel-wired-lan@...ts.osuosl.org, netdev@...r.kernel.org,
	eric.dumazet@...il.com
Subject: Re: [PATCH 0/3 net-next] Bring sizeof(net_device) down to < 2K bytes

On 04/09/15 at 05:01pm, Alexei Starovoitov wrote:
> On Fri, Apr 10, 2015 at 01:43:25AM +0200, Thomas Graf wrote:
> > The size of struct net_device crossed the 2K boundary a while ago which
> > is a waste in combination with many net namespaces. This series brings
> > the size of struct net_device down to well below 2K in total size with
> > a typical configuration. Some reserves a several holes leave room for
> > further expansion.
> 
> Great stuff!
> Can you share what was the sizeof(struct net_device) with typical
> x86 config before and after?

Before:

/* BRAIN FART ALERT! 2176 != 2091 + 41(holes), diff = 44 */

After:

/* size: 1984, cachelines: 31, members: 121 */
/* sum members: 1947, holes: 6, sum holes: 33 */
/* padding: 8 */
/* paddings: 2, sum paddings: 11 */

/* BRAIN FART ALERT! 1984 != 1947 + 33(holes), diff = 4 */
--
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