cygwin performance hit

[Larry Hall]

vikramshrowty@yahoo.com wrote:

> Hi,	
> 	Im seeing a severe perfomance hit from cygwin. Heres the result of
> $time make_depend with a cygwin-compiled makedepend:
> ------------------------------------------------------------------------
> 2.65user 27.90system 9:22.59elapsed 5%CPU (0avgtext+0avgdata 49856maxresident)k
> 0inputs+0outputs (3190major+0minor)pagefaults 0swaps
> ------------------------------------------------------------------------
> and heres the output from a -mno-cygwin compiled makedepend:(the same code)
> ------------------------------------------------------------------------
> 0.09user 0.04system 2:13.47elapsed 0%CPU (0avgtext+0avgdata 43280maxresident)k
> 0inputs+0outputs (2781major+0minor)pagefaults 0swaps
> ------------------------------------------------------------------------
> 
> I ran an strace on the cywinized makdepend and ran a sort -k 1 -r on
> the output.( to sort the functions by the time-delta). There are a lot
> of calls to GetFileAttributes at the top of the sorted output...like this
> 
> ------------------------------------------------------------------------
> 97332 19244539 [main] build_makedepend 331 symlink_info::check:
> GetFileAttributes (\\asic-auth\homes\NT\dev\src\tool\tool-list\sys.h)
> failed
> ------------------------------------------------------------------------
> 
> Thats a network mounted directory so I suppose some slowdown is
> expected but shouldnt the native (-mno-cygwin) version see the same
> slowdown? Is there a reason for cygwin-compiled programs to see a
> larger hit?


Beyond the fact that makedepend calls into system services for Cygwin
go through an emulated API and POSIX path to Win32 path conversion, no.


-- 
Larry Hall                              http://www.rfk.com
RFK Partners, Inc.                      (508) 893-9779 - RFK Office
838 Washington Street                   (508) 893-9889 - FAX
Holliston, MA 01746


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/