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Date: Thu, 3 Jun 2010 19:57:31 -0700
Subject: Re: Cygwin Performance and stat()
From: "Christopher Wingert" <mailbox AT wingert DOT org>
To: cygwin AT cygwin DOT com
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> On Thu, Jun 03, 2010 at 05:32:46PM -0700, Christopher Wingert wrote:
> Yeah, that's what I thought you were doing.  Given that the timestamps
> don't indicate "elapsed time of function X", it's not always possible to
> figure out how long a function takes by subtracting.  Subtracting
> timestamps shows the delta between one time that someone thought to put
> an strace_printf in the code and another time that someone thought to
> put an strace_printf in the code.  There is no guarantee that there is
> an strace_printf at entry or exit of a function.

Yes, except that someone instrumenting the entry/exit points was me, and
the fact that they are not actually real syscalls and no other cygwin
processes are running says the timestamps are accurate for the purposes of
debugging.  Further the numbers match up with the overall timings I did
before the debugging.


> It is a shame that we weren't more standardized in our strace output so
> that kind of thing could be possible.

Agreed (for once), the instrumentation of the syscalls and the fact that
they are sprinkled over multiple files made things very difficult to
debug.


> However, for Cygwin, the web site says multiple times in multiple places
> that you shouldn't send private email and to use the mailing list.  So,
> other projects aside that really is how we do things here.

Understood.  I'll wait with bated breath for a knowledgeable developer to
speak up.



> Oh, and it isn't clear if you're implying that I'm a lackey but I'm
> really not.

Hmmmm, I thought it was abundantly clear.





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