Here is the detailed ConTest data, first for 2.5.52-mm2 with the
default tunables, then with the settings listed above. Two comments
about how I use ConTest so you don't wig out about low numbers: 1) I
compile qmail with a tailored Makefile instead of the kernel; 2) I
limit the size of the tempfile to 100MB (instead of the 1GB my setup
would normally yield). On with the detailed data (sorry, I don't have
the original *.logs to build the -r report):
Default tunables
noload Time: 18.82 CPU: 171% LoadRuns: 0 LoadCPU%: 0 Major Faults:
368526 Minor Faults: 181377
process_load Time: 25.12 CPU: 125% LoadRuns: 18 LoadCPU%: 74%
Major Faults: 368526 Minor Faults: 181375
ctar_load Time: 32.73 CPU: 139% LoadRuns: 206 LoadCPU%: 31% Major
Faults: 368527 Minor Faults: 181378
xtar_load Time: 30.51 CPU: 152% LoadRuns: 79 LoadCPU%: 26% Major
Faults: 368528 Minor Faults: 181376
io_load Time: 37.13 CPU: 118% LoadRuns: 125 LoadCPU%: 40% Major
Faults: 368524 Minor Faults: 181376
read_load Time: 31.20 CPU: 99% LoadRuns: 1147 LoadCPU%: 99% Major
Faults: 368524 Minor Faults: 181377
list_load Time: 22.33 CPU: 151% LoadRuns: 0 LoadCPU%: 4% Major
Faults: 368526 Minor Faults: 181376
mem_load Time: 39.70 CPU: 106% LoadRuns: 88 LoadCPU%: 14% Major
Faults: 368533 Minor Faults: 183364
noload Time: 18.67 CPU: 171% LoadRuns: 0 LoadCPU%: 0 Major Faults:
368527 Minor Faults: 181378
process_load Time: 20.57 CPU: 154% LoadRuns: 10 LoadCPU%: 49%
Major Faults: 368527 Minor Faults: 181377
ctar_load Time: 24.48 CPU: 195% LoadRuns: 164 LoadCPU%: 20% Major
Faults: 368527 Minor Faults: 181381
xtar_load Time: 31.33 CPU: 141% LoadRuns: 83 LoadCPU%: 24% Major
Faults: 368526 Minor Faults: 181376
io_load Time: 32.06 CPU: 154% LoadRuns: 159 LoadCPU%: 55% Major
Faults: 368526 Minor Faults: 181377
read_load Time: 30.11 CPU: 103% LoadRuns: 1044 LoadCPU%: 95% Major
Faults: 368527 Minor Faults: 181376
list_load Time: 19.49 CPU: 172% LoadRuns: 0 LoadCPU%: 8% Major
Faults: 368527 Minor Faults: 181377
mem_load Time: 47.46 CPU: 102% LoadRuns: 97 LoadCPU%: 11% Major
Faults: 369220 Minor Faults: 184244
noload Time: 18.56 CPU: 172% LoadRuns: 0 LoadCPU%: 0 Major Faults:
368528 Minor Faults: 181376
process_load Time: 26.16 CPU: 120% LoadRuns: 20 LoadCPU%: 77%
Major Faults: 368525 Minor Faults: 181375
ctar_load Time: 68.20 CPU: 68% LoadRuns: 428 LoadCPU%: 14% Major
Faults: 368525 Minor Faults: 181381
xtar_load Time: 28.97 CPU: 163% LoadRuns: 85 LoadCPU%: 25% Major
Faults: 368527 Minor Faults: 181376
io_load Time: 29.25 CPU: 164% LoadRuns: 126 LoadCPU%: 48% Major
Faults: 368526 Minor Faults: 181377
read_load Time: 31.03 CPU: 100% LoadRuns: 1115 LoadCPU%: 97% Major
Faults: 368525 Minor Faults: 181377
list_load Time: 21.81 CPU: 155% LoadRuns: 0 LoadCPU%: 8% Major
Faults: 368526 Minor Faults: 181377
mem_load Time: 47.05 CPU: 88% LoadRuns: 96 LoadCPU%: 11% Major
Faults: 368552 Minor Faults: 181433
Tweaked tunables
noload Time: 18.62 CPU: 172% LoadRuns: 0 LoadCPU%: 0 Major Faults:
368528 Minor Faults: 181384
process_load Time: 27.54 CPU: 114% LoadRuns: 25 LoadCPU%: 81%
Major Faults: 368527 Minor Faults: 181383
ctar_load Time: 27.53 CPU: 171% LoadRuns: 181 LoadCPU%: 30% Major
Faults: 368528 Minor Faults: 181388
xtar_load Time: 32.61 CPU: 127% LoadRuns: 74 LoadCPU%: 20% Major
Faults: 368525 Minor Faults: 181385
io_load Time: 42.57 CPU: 113% LoadRuns: 204 LoadCPU%: 46% Major
Faults: 368527 Minor Faults: 181384
read_load Time: 22.66 CPU: 141% LoadRuns: 312 LoadCPU%: 44% Major
Faults: 368527 Minor Faults: 181384
list_load Time: 21.63 CPU: 158% LoadRuns: 0 LoadCPU%: 4% Major
Faults: 368526 Minor Faults: 181383
mem_load Time: 44.48 CPU: 96% LoadRuns: 93 LoadCPU%: 12% Major
Faults: 368528 Minor Faults: 181402
noload Time: 18.70 CPU: 172% LoadRuns: 0 LoadCPU%: 0 Major Faults:
368525 Minor Faults: 181385
process_load Time: 27.37 CPU: 115% LoadRuns: 25 LoadCPU%: 82%
Major Faults: 368527 Minor Faults: 181382
ctar_load Time: 73.84 CPU: 62% LoadRuns: 498 LoadCPU%: 19% Major
Faults: 368525 Minor Faults: 181388
xtar_load Time: 25.15 CPU: 163% LoadRuns: 58 LoadCPU%: 24% Major
Faults: 368527 Minor Faults: 181385
io_load Time: 35.49 CPU: 118% LoadRuns: 112 LoadCPU%: 33% Major
Faults: 368525 Minor Faults: 181385
read_load Time: 23.11 CPU: 137% LoadRuns: 517 LoadCPU%: 63% Major
Faults: 368525 Minor Faults: 181383
list_load Time: 21.61 CPU: 157% LoadRuns: 0 LoadCPU%: 4% Major
Faults: 368528 Minor Faults: 181383
mem_load Time: 42.15 CPU: 130% LoadRuns: 90 LoadCPU%: 13% Major
Faults: 368524 Minor Faults: 181466
noload Time: 18.95 CPU: 169% LoadRuns: 0 LoadCPU%: 0 Major Faults:
368526 Minor Faults: 181384
process_load Time: 27.44 CPU: 114% LoadRuns: 24 LoadCPU%: 83%
Major Faults: 368527 Minor Faults: 181384
ctar_load Time: 23.68 CPU: 191% LoadRuns: 155 LoadCPU%: 16% Major
Faults: 368527 Minor Faults: 181388
xtar_load Time: 31.76 CPU: 137% LoadRuns: 65 LoadCPU%: 23% Major
Faults: 368527 Minor Faults: 181386
io_load Time: 33.40 CPU: 123% LoadRuns: 150 LoadCPU%: 45% Major
Faults: 368527 Minor Faults: 181385
read_load Time: 21.26 CPU: 147% LoadRuns: 424 LoadCPU%: 57% Major
Faults: 368526 Minor Faults: 181384
list_load Time: 20.29 CPU: 167% LoadRuns: 0 LoadCPU%: 4% Major
Faults: 368527 Minor Faults: 181383
mem_load Time: 51.10 CPU: 130% LoadRuns: 98 LoadCPU%: 12% Major
Faults: 368596 Minor Faults: 181598
Finally, it crossed my mind that completely subjective monitoring of X
jerkiness perhaps wasn't the most scientific way of measuring the
interactive impact of the tunables. I'm no Evil Scientist, but I
whipped up a perl script that I think accomplishes something close to
capturing those statistics. It captures 1000 samples of what should
be a precise .2 second delay (on an idle system it is, with a tiny
bit of noise).
Here's the script, along with some output produced while the system
was under considerable load. Would something like this be worth
developing further to help rigorously measure the interactive impact
of the tunables? Or is there a flaw in the approach?
#!/usr/bin/perl
use strict;
use warnings;
use Time::HiRes qw/sleep time/;
my %pause = ();
for (my $x = 0; $x < 1000; $x++) {
my $start = time();
sleep(.2);
my $stop = time();
my $elapsed = $stop - $start;
$pause{sprintf('%01.3f', $elapsed)}++;
}
foreach (sort(keys(%pause))) {
print "$_: $pause{$_}\n";
}
exit 0;
Sample output
time ./int_resp_timer.pl
0.192: 1
0.199: 1
0.200: 10
0.201: 201
0.202: 53
0.203: 25
0.204: 22
0.205: 21
0.206: 34
0.207: 29
0.208: 29
0.209: 100
0.210: 250
0.211: 120
0.212: 35
0.213: 16
0.214: 17
0.215: 14
0.216: 9
0.217: 1
0.218: 3
0.219: 3
0.220: 1
0.222: 1
0.233: 1
0.303: 1
0.304: 1
0.385: 1
real 3m28.568s
user 0m0.329s
sys 0m1.260s
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