On Feb 23, 2015, at 11:42, Rui Paulo <[email protected]> wrote: > How much time did this save?
Test profile:
- 4 x CPU VMware Fusion hosted amd64 VM with 4GB allocated to it and with
open-vm-tools installed
- Kernel with WITNESS watch turned on.
- Multiuser mode (because I’m lazy)
The worst case scenario was tested:
- All BOOTSTRAPPING checks were removed
- The default SRCCONF values were set
- I built with i386 instead of amd64 (to force elftoolchain and the dtrace
tools to always be built).
Observations:
-j1: standard deviation was huge (5.75 is not statistically accurate), so I
threw out a few outliers and redid the numbers.
-j1 vs -j4: ~3 minutes faster -> ~3x speedup
-j4 vs -j8: -> no real noticeable change, but the outliers were statistically
larger.
Cheers!
========================
-j1:
$ grep ' 1:.*real' ts | awk 'NR > 1 { print $3 }' | ministat
x <stdin>
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| x
|
| x x x x x x
x
x x|
||__________________________________________________M____________________A_______________________________________________________________________|
|
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 10 259.57 275.06 263.04 264.747 5.7545094
-j1 (statistically more accurate sample, but smaller sample size):
$ grep ' 1:.*real' ts | awk 'NR > 1 && NR < 8 { print $3 }' | ministat
x <stdin>
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| xx x
x x
x|
||____________________________________________________________________________________A____________________________________M________________________________________________|
|
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 6 260.45 263.8 262.46 261.83667 1.4530336
-j4:
$ grep ' 4:.*real' ts | awk 'NR > 1 { print $3 }' | ministat
x <stdin>
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|x x x x
x x x
x xx|
|
|______________________________________________________________________________A_M___________________________________________________________________________|
|
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 10 87.78 90.34 89.04 89.011 0.99822565
$ grep ‘ 8:.*real' ts | awk 'NR > 1 { print $3 }' | ministat
x <stdin>
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|x x x x
x x x x x
x|
|
|________________________________________________________A_____M__________________________________________________|
|
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 10 87.66 93.91 90.77 90.572 1.7769249
-j1 (statistically inaccurate) vs -j4:
$ python2.7 -c 'm1 = 264.747; m4 = 89.011; print (m1/m4), (m1-m4)'
2.97431778095 175.736
-j1 (statistically accurate) vs -j4:
$ python2.7 -c 'm1 = 261.83667; m4 = 89.011; print (m1/m4), (m1-m4)'
2.94162148499 172.82567
signature.asc
Description: Message signed with OpenPGP using GPGMail
