[Fedora-ia64-list] RFC: Thoughts on SPARSE memory

[Luck, Tony]

> lmbench results for 4p/4G SGI 330, and 64p/128G SGI 3700bx2 ...

Thanks for running these and posting the results ... but this section
at least looks like a random number generator was used!

Context switching - times in microseconds - smaller is better
-------------------------------------------------------------
Host                 OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
                        ctxsw  ctxsw  ctxsw ctxsw  ctxsw   ctxsw   ctxsw
--------- ------------- ----- ------ ------ ------ ------ ------- -------
4p-DISCON Linux 2.6.17- 1.700   20.3   22.1   20.1   25.3    17.8    25.9
4p-SPARSE Linux 2.6.17-  16.9 2.9700 6.2700   14.2   10.3    16.4    17.3

DISCONTIG is either 10 times better, or 6.8 times worse than SPARSE :-(

Did you run the new(ish) version of lmbench that can bind processes to
particular cpus to help cut down on such erratic results?

-Tony