On 2011-08-29 07:56+1000 Ben Peddell wrote:
On 29/08/2011 2:37 AM, Alan W. Irwin wrote:
bash.exe-3.1$ time /z/home/wine/newstart1/MinGW/msys/1.0/bin/echo.exe hello hello
real 0m0.503s user 0m0.080s sys 0m0.020s
Also, I tried time (x; x; x; x; x; x; x; x; x; x), where "x" represents the complete echo command above, and the result was
real 0m5.281s user 0m0.800s sys 0m0.200s
[snip]
While I am doing those additional investigations, please consider the question of why there is a huge difference between built-in and executable latency for MSYS bash commands under wine. To start that investigation it would be good to compare the wine results for those two cases with the Windows results for those two cases. (I assume the two time results for built-in versus executable will be fairly similar in the Windows case, but that assumption needs to be checked.) I don't have access to Windows myself. Anybody up for doing that simple test and reporting the results back here? The automatic MinGW/MSYS installer at http://sourceforge.net/projects/mingw/files/Automated MinGW Installer/mingw-get-inst/ makes it easy to install the relevant MinGW/MSYS software on both wine and Windows.
Under MSYS 1.0.17 running on Windows 7 x64 SP1:
bash.exe-3.1$ /bin/bash --version GNU bash, version 3.1.17(1)-release (i686-pc-msys) Copyright (C) 2005 Free Software Foundation, Inc.
bash.exe-3.1$ alias x='/bin/echo.exe -n .'
bash.exe-3.1$ time x . real 0m0.031s user 0m0.000s sys 0m0.015s
bash.exe-3.1$ time (x;x;x;x;x;x;x;x;x;x) .......... real 0m0.296s user 0m0.075s sys 0m0.136s
This shows a latency of approximately 2 jiffies for each command - 1 jiffy in Windows is 15.6ms.
-- Ben Peddell IT Support Bowen, Collinsville, Proserpine and Home Hill Catholic schools http://klightspeed.killerwolves.net/
Thanks, Ben, for doing the requested test for the executable echo test. That shows the Windows startup latency is measureable but acceptable for that executable. Just out of curiosity, what happens for the corresponding bash executable built-in echo functionality? Is it essentially instantaneous (i.e., elapsed time less than 0.001 seconds) like in the wine case?
Alan __________________________ Alan W. Irwin
Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca).
Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); the Time Ephemerides project (timeephem.sf.net); PLplot scientific plotting software package (plplot.sf.net); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________
Linux-powered Science __________________________