Dave Korn wrote:
On 26 May 2006 16:38, mwoehlke wrote:
[snip]
Way way back in the OP, I mentioned that Interix doesn't have this
problem, which would imply a "design flaw" in Cygwin. Maybe (probably)
it is a *necessary* design flaw, BUT...
You are now piling pointless and incorrect speculation on your invalid and
groundless assumptions. This is a waste of time.
I don't consider reducing the possible cause of the to be a waste of time.
On ONE computer, I am running the same command from the same NFS mount,
using bash-3.1 in both cases (Interix is 3.1.0, Cygwin is 3.1.17). That
is a /number/ of controlled variables, with Cygwin/Interix being the
obviously different one. Under those circumstances, I observe a very
noticeable difference in execution times.
If that isn't a "bug" - and the (constructive) responses I have gotten
seem to think it isn't - then it is a problem with the implementation of
Cygwin on top of the Windows subsystem. I classify that as "a problem
inherent in the design which is necessitated by the underlying
architecture". Please try to understand that I am not attempting to
insult Cygwin. In fact, I am trying to shift blame *away* from Cygwin!
[snip]
See if you can find out where that line of code comes from. Then read the
source code to the MSVCRT version of stat, which is shipped with VC, to see
how it gets the timestamps etc. Then disassemble FindFirstFileExW in windbg
and see whether or not it opens the files that it calls.
Then post again and explain how you think interix could stat a file without
having an open handle to it.
Interix is a different /subsystem/, with a totally different means of
interacting with the underlying file system (particularly NFS) than the
Windows subsystem. It probably doesn't make anything even resembling the
same systems calls as Cygwin.
Then post again and explain how you managed to tell that cygwin's having to
open the file is a substantial part of the speed difference between cygwin and
interix without having once read the source, profiled the code, or timed or
tested anything.
Sigh. Go back and read my OP. Notice that I attached an strace. Explain
to me that the detailed profiling/timing information does not qualify as
"profiling" or "time testing". Please do not make patently false claims
that I have not attempted to diagnose the problem.
I will of course keep the list up to date of any pertinent findings.
--
Matthew
Feed the hippo. Love the hippo. Run from the hippo.
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