Re: [PATCH - RFC] [1/5] 64-bit network statistics - generic net

Jeff Sipek (jeffpc@optonline.net)
Sat, 05 Jul 2003 16:37:43 -0400


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Saturday 05 July 2003 15:58, Bernd Eckenfels wrote:
> a reader like ifconfig can easyly work around this with multiple tries, but
> incremeting those variables wont work that easy, and therefore needs a
> lock, which will be a major pita.
>
> 64bit counters should be a result of lockless per-cpu network counters
> (32bit) with some kind of async merging.

This is going to make the structure huge - not only you have the 32-bit
variables for every CPU, but you have one global set of 64-bit variables
(possibly you will need a lock for the 64-bit vars.)

Also another thing to consider is portability across architectures - we don't
need all this code on 64-bit arches.

On the other hand, per-cpu stats may possibly make up for the extra code - no
cache bouncing, etc.

> Or we wait till 64bit hardware is more common :)

Hehe, the thing is, that when 64bits beecome more common you will have this
huge number of unused x86 computers that people will:

- - throw out
- - donate
- - convert to all sorts of "embedded" systems which need stable OS (read:
Linux) (these include routers)

So, x86 is here to stay for some time.

Jeff.

- --
The Moon is Waxing Crescent (36% of Full)
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.2 (GNU/Linux)

iD8DBQE/BzcbwFP0+seVj/4RAuMHAJ9sN0E4OgsPeM09D6hbgM3boECLDwCbBDTP
6u8SSobW0+Y0oWq3H4koHd0=
=Z89A
-----END PGP SIGNATURE-----

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