From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: Synchronization problem with posix_spawn
Date: Mon, 3 Aug 2020 12:50:04 +0200 [thread overview]
Message-ID: <20200803105004.GK460314@calimero.vinschen.de> (raw)
In-Reply-To: <9c44f4351d459a2ba8d27c65bf71679208cb13d6.camel@tdcadsl.dk>
On Aug 3 11:10, Peter Dons Tychsen via Cygwin wrote:
> Hi all,
>
> On Fri, 2020-07-31 at 10:10 +0200, Corinna Vinschen wrote:
> > Oh well. I did a quick test with your new testcase (thanks for
> > that!)
> > and it seems to be a bit more complicated than I anticipated
> > yesterday.
> > The parent-child relationship between the processes is broken. I
> > have
> > to think a while about this problem, stay tuned.
>
> I also have seen this problem. I propose a different solution however.
> Why no get rid of the call to fork() all together. One of the things
> bogging down performance on larger setups is the calls to fork() are is
> inherently slow and should be avoided at all costs. Instead why don't
> we just call spawn(vpe) instead, which is quite stable and fast.
>
> This would give a _huge_ boost to e.g. larger build jobs. Make supports
> posix_spawn, but it does not help on cygwin at it just calls back into
> fork().
spawn alone doesn't cut it, due to the requirement to support the
additional file actions and spawn atributes POSIX defines. This
would require a revamp of Cygwin's spawn functionality, which is
already quite complicated. So this is something I'm only willing
to do in homeopathic doses.
Corinna
--
Corinna Vinschen
Cygwin Maintainer
next prev parent reply other threads:[~2020-08-03 10:50 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-29 20:17 Ken Brown
2020-07-29 23:12 ` Ken Brown
2020-07-30 11:59 ` Corinna Vinschen
2020-07-30 17:17 ` Corinna Vinschen
2020-07-30 23:04 ` Ken Brown
2020-07-31 8:10 ` Corinna Vinschen
2020-08-03 9:10 ` Peter Dons Tychsen
2020-08-03 10:50 ` Corinna Vinschen [this message]
2020-08-20 5:40 ` Peter Dons Tychsen
2020-08-20 12:50 ` Corinna Vinschen
2020-08-21 7:58 ` Peter Dons Tychsen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200803105004.GK460314@calimero.vinschen.de \
--to=corinna-cygwin@cygwin.com \
--cc=cygwin@cygwin.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).