From: <sten.kristian.ivarsson@gmail.com>
To: <cygwin@cygwin.com>
Subject: Sv: Limit for number of child processes
Date: Thu, 27 Aug 2020 14:17:42 +0200 [thread overview]
Message-ID: <000701d67c6c$10bcf720$3236e560$@gmail.com> (raw)
In-Reply-To: <20200826175724.GQ3272@calimero.vinschen.de>
Hi Corinna
> > Dear cygwin folks
> >
> > It seems like there's a limit of the number of possible child
> > processes defined to 256 with 'NPROCS' in //winsup/cygwin/child_info.h
> > used in 'cprocs' in //winsup/cygwin/sigproc.cc
> >
> > 256 is quite few possible children in an enterprise environment and
> > perhaps the limit should be limited by the physical resources or
> possibly Windows ?
>
> The info has to be kept available in the process itself so we need this
> array of NPROCS * sizeof (pinfo).
>
> Of course, there's no reason to use a static array, the code could just as
> well use a dynamically allocated array or a linked list. It's just not
> the way it is right now and would need a patch or rewrite.
>
> As for the static array, sizeof pinfo is 64, so the current size of the
> array is just 16K. We could easily bump it to 64K with NPROCS raised to
> 1024 for the next Cygwin release, at least on 64 bit.
> I don't think we should raise this limit for 32 bit Cygwin, which is kind
> of EOL anyway, given the massive restrictions.
I don't know the exact purpose of this and how the cprocs is used, but I'd
prefer something totally dynamic 7 days out of 7 or otherwise another limit
would just bite you in the ass some other day instead ;-)
A linked list could be used if you wanna optimize (dynamic) memory usage but
an (amortized) array would probably provide faster linear search but I guess
simplicity of the code and external functionality is the most important
demands for this choice
I'm looking forward for a future release where there's no children limit
Keep up the good work
Best regards,
Kristian
> Corinna
>
> --
> Corinna Vinschen
> Cygwin Maintainer
> --
> Problem reports: https://cygwin.com/problems.html
> FAQ: https://cygwin.com/faq/
> Documentation: https://cygwin.com/docs.html
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next prev parent reply other threads:[~2020-08-27 12:17 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-26 12:00 sten.kristian.ivarsson
2020-08-26 17:57 ` Corinna Vinschen
2020-08-27 12:17 ` sten.kristian.ivarsson [this message]
2020-08-28 1:42 ` Sv: " Ken Brown
2020-08-28 8:35 ` Corinna Vinschen
2020-08-28 8:38 ` Sv: " sten.kristian.ivarsson
2020-08-28 12:29 ` Ken Brown
2020-08-28 13:36 ` Corinna Vinschen
2020-08-28 14:09 ` Sv: " sten.kristian.ivarsson
2020-08-28 16:02 ` Ken Brown
2020-08-28 17:39 ` Corinna Vinschen
2020-08-29 10:01 ` Ken Brown
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