On Fri, Jul 06, 2007 at 04:55:47PM -0400, Colin Walters wrote:
Possibly, but I think the biggest speedup by far is the disk
caching/reorganization that both Windows and OS X do:
http://www.kernelthread.com/mac/apme/optimizations/
At this rate though, we might all be using solid state drives before the
kernel developers stop pointing at userspace as the problem and
implement it for Linux.
We already lay stuff out very carefully and precache. Unfortunately most
of the mess *is* userspace and some of the userspace authors are in
complete denial. Just profile the number of file opens of different files
done in a gnome startup and when you've finished laughing you can weep.
Years ago I sent the gnome team a library that could load and linearlly
map the entire theme in about 3 syscalls coming out nicely on disk. They
never used it.
That isn't to say the kernel is perfect and there is a ton of optimising
work still going on, different scheduling algorithms and the like but
most of the slowness is from user space - some from tools, some from
combinations of tools and kernel (eg linker and paging patterns) and a lot
of it from sheer stupid clueless design of applications and especially
of GUI libraries.
Alan