Cygwin Filesystem Performance degradation 1.7.5 vs 1.7.7, and methods for improving performance

[Corinna Vinschen]

On Oct  4 12:23, Corinna Vinschen wrote:
> On Oct  3 23:33, Derry Shribman wrote:
> > We have NOD32 anti-virus installed on all XP PCs at our work place.
> > So that may probably be one of the reasons for the XP slowdown. Can
> > you run the test program on an XP at your place and see how results
> > differ?
> 
> Well, I can try, but it's a VM, too.

The results on a VM are apparently very unreliable.  Here are the
numbers on a XP VM using the latest Cygwin from CVS.  I ran the
tests 10 times in a row.  "lsta1" is Cygwin's lstat with full stat
info, including correct POSIX permissions.  "lsta2" is with /bin
mounted "noacl,notexec,ihash".

Worst results:

  testing /bin lsta1 2015 files stat()  366.2ms,  per file: 0.1817ms
  testing /bin lsta2 2015 files stat()  215.8ms,  per file: 0.1071ms
  testing /bin GFA   2015 files stat()   86.91ms, per file: 0.04313ms
  testing /bin QIF   2015 files stat()  144.5ms,  per file: 0.07173ms
  testing /bin QDF   2015 files stat()  103.5ms,  per file: 0.05137ms

Best results:

  testing /bin lsta1 2015 files stat()  232.4ms,  per file: 0.1153ms
  testing /bin lsta2 2015 files stat()  175.8ms,  per file: 0.08724ms
  testing /bin GFA   2015 files stat()   76.17ms, per file: 0.0378ms
  testing /bin QIF   2015 files stat()  117.2ms,  per file: 0.05816ms
  testing /bin QDF   2015 files stat()   85.94ms, per file: 0.04265ms

Average ratio QDF/lsta1 is 1/3.2, QDF/lsta2 is 1/2.1


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat