Re: Ottawa - kernel hackers ...

[Alan Cox <alan redhat com>]

> 	Fancy elevators, improved schedulers, etc. are all very fun but
> improving the swap performance[1], and doing more intelligent predictive
> read-ahead is what we need surely ? :-)

Fancy elevator algorithms and the readahead stuff people are fiddling with
are as relevant to the desktop as big servers.

> [1] - it's quite amazing to quit X after a long session and see the X
> background pixmap re-render from swap: a huge area of flat memory - with
> uniform non-use for the last some hours - and the pixels are scattered
> all over the disk - hmm, at ~1 block per line it takes the ~10 seconds
> (1024*10ms) you'd expect to render. Just killall -9 nautilus to see.

See thermodynamics, subsection entropy.

And once you have the data scattered it gets really fun because disk seek
time hasnt really improved in years, so its 50Mb/sec linear, 2Mb/sec seeking
hard.

X or gnome could choose to keep file mappings of these objects in theory
but currently don't