Re: cygwin slowdown in current cvs version

[Christopher Faylor <cgf at redhat dot com>]

On Sat, Sep 08, 2001 at 10:59:44PM +0400, egor duda wrote:
>Hi!
>
>Saturday, 08 September, 2001 egor duda deo@logos-m.ru wrote:
>
>ed>>   did anybody noticed that cygwin runs slower than before? i've just
>ed>> tried to perform full rebuild of newlib and received the following
>ed>> results:
>
>[...]
>
>ed> Yet, it's only half of the story. cvs build from just before this
>ed> change still work slower than the build i've used daily since the
>ed> beginning of August. I'll try to dig a little deeper now.
>
>ok. after going back to as far as 1st of June i've started to think
>that i should probably take some lessons in, ehr, positive thinking :)
>
>it looks like the rest 10% of slowdown is not actually a "slowdown"
>but rather a 10% speedup... I don't remember for sure but it looks
>pretty much like i've been running my locally-hacked version of
>cygwin1.dll, which replaced statically-allocated /dev/dsp buffer with
>malloc()ed one. I'm not sure if such change could account for 10% of
>performance, but we're getting too close to the statistical noise
>threshold here to know for sure.
>
>To resume. I think we should back out Corinna's "reread /etc/passwd"
>patch for now, wait for some time until dust settles, and release
>1.3.3. after that i'll try to remake my /dev/dsp patch and see what
>performance gains it gives (if any).

Have you compared the numbers against 1.3.2 by any chance?

It occurred to me today that by moving the large zombies buffer into the
heap, I ended up having fork always copy the array.  I don't know which
is better -- having a large dll with a slower load time vs more to copy
on fork.

Have you tried backing out the zombies change, too?

cgf