DragonFly kernel List (threaded) for 2003-11
AMD64 impressions (Re: AMD64 box)
I was able to boot the AMD box with APMBIOS commented out (FreeBSD-4.x
also can't boot the box with APMBIOS turned on either. I'll test
FreeBSD-current later today).
I ran some preliminary buildworld benchmarks. I don't have equivalent
machines but a few things are obvious from the results:
(1) The AMD box is very fast. Very, very fast. It blows away everything
else hands down. It is so fast that it spends nearly 1/3 of its
time waiting on I/O despite the fact that the I/O requirements
for a buildworld are fairly minimal. It is so fast it makes my P4
look like a snail, and even puts my DELL2550 (which is no slouch)
The best comparison is the AMD box verse the P4 box. Both are UP
boxes. The AMD box is 2.1x faster then the P4 box. If clock speeds
scaled, that would make the AMD box equivalent to 2.6GHz P4. Since
clock speeds don't scale, the AMD box is more like a 3.3GHz P4.
(2) The AMD's syscall overhead is very low compared to the P4.
I ran the 'sc1' test in /usr/src/test/sysperf. The AMD box
comes back at 242nS/loop while the P4 takes 1300nS/loop and
the DELL box (LEAF/SMP) takes 617nS/loop.
(3) I need to work on the SYS time for DragonFly SMP. LEAF's SYS
time should be around 400s, not 961s. It's the SMP lwkt_token code
being used for the vnode locks that is the likely culprit. LEAF
is a 2xCPU DELL-2550 and no slouch (not like VALinux 2xCPU box which
is a piece of junk). LEAF should have done better then it did.
/usr/bin/time -l make -j 4 buildworld (of dragonfly's /usr/src)
(a) AMD Athlon(tm) 64 Processor 3200+ (2002.57-MHz 686-class CPU)
Running DragonFly, UP build. 1 cpu. (with two PC3200 512M sticks)
(b) Intel(R) Pentium(R) III CPU family 1133MHz (1125.77-MHz 686-class CPU)
Running DragonFly, SMP build. 2 cpus. (PC133 SDRAM, but a fast DELL bus)
(c) Intel Pentium III (746.76-MHz 686-class CPU)
Running FreeBSD-4.x, SMP build, 2 cpus. (PC133 SDRAM)
(d) Intel(R) Pentium(R) 4 CPU 1300MHz (1296.07-MHz 686-class CPU)
Running FreeBSD-4.x, UP build, 1 cpu. (with RDRAM)
(a) 1237.27 real 742.21 user 171.86 sys 1xAMD / DragonFly
(b) 1697.20 real 1370.54 user 961.67 sys 2xP3@xxxxxx / DragonFly
(c) 2271.17 real 2482.18 user 983.53 sys 2xP3@750MHz / FreeBSD
(d) 2656.12 real 1825.19 user 461.28 sys 1xP4@xxxxxx / FreeBSD