Re: Cygwin Perl has slowed in recent months

[David Christensen <dpchrist@holgerdanske.com>]

On 5/23/22 11:47, Lee wrote:
> On 5/22/22, David Christensen wrote:
>> On 5/21/22 10:55, Hans-Bernhard Bröker wrote:
>>> Am 18.05.2022 um 03:53 schrieb David Christensen:
>>>
>>>   > I am working on a Perl module that runs on various Unix-like platforms.
>>>   > When I 'make test' on similar computers:
>>>   >
>>>   > FreeBSD 12.3-RELEASE         28 wallclock secs
>>>   > Debian GNU/Linux 11.3          31 wallclock secs
>>>   > macOS 11.6.2              36 wallclock secs
>>>   > Windows 7 / Cygwin 3.3.5-1    509 wallclock secs

>> I was hoping there was a known issue.

> What I consider a well known issue is that process start up time is
> _very_ slow.  If your  'make test' starts lots of processes that could
> be a problem.


[Replying to off-list message.]


Thank you for the reply.


'make test' starts a large number of processes -- perhaps a thousand.


> Another huge slowdown is Windows Defender.  Try turning that off and
> seeing how long your 'make test' takes then.


Of all the test scripts, 02-compile.t consumes the most time on all 
platforms.


Using 02-compile.t as a benchmark, here is the compile time with Windows 
Defender enabled:

$ time perl -Ilib t/02-compile.t
<snip>
real    2m1.404s
user    3m20.490s
sys     4m24.476s


Here is the compile time with Windows Defender disabled:

$ time perl -Ilib t/02-compile.t
<snip>
real    1m56.606s
user    3m14.374s
sys     4m20.106s


Both of the above tests were run in Cygwin64 Terminal.  Using Debian and 
SSH:

$ time perl -Ilib t/02-compile.t
<snip>
real	1m18.733s
user	2m32.187s
sys	2m29.652s


So, Cygwin64 Terminal is also a problem.


In all cases, Resource Monitor indicates the script is CPU bound.


David