On Thu, 12 Apr 2012 23:04:33 +0200
Johnny Billquist<bqt%softjar.se@localhost> wrote:
Funny you should say that, while a CVS checkout of all of the NetBSD
source tree have grown in time from about 20 minutes to about 5 hours on
a VAX-8650 as we move from NetBSD 2 to NetBSD 5. Did we really improve
performance, or did we only just get faster computers, while the code
itself got slower?
Faster hardware, but also software that adapts better to that hardware:
Most of the performance improvements I was refering to happened
between netbsd-4 and netbsd-5, when Andrew Doran worked full-time on
performance and SMP:
http://blog.netbsd.org/tnf/entry/netbsd_5_0_an_overview
This included changing a number of operations that were previously
executing in O(n) time to now execute in O(1) time, making MP-safe some
critical sections, not using the big lock anymore for MP-safe sections,
scheduler and interrupt processing changes, a new 1:1 POSIX threading
system that can more easy scale with SMP, etc.