From: Alan Third <alan@idiocy.org>
To: Aaron Jensen <aaronjensen@gmail.com>
Cc: 26397@debbugs.gnu.org
Subject: bug#26397: 25.1; call-process slow on macOS and slower on larger frames
Date: Sun, 9 Apr 2017 14:01:55 +0100 [thread overview]
Message-ID: <20170409130155.GA59432@breton.holly.idiocy.org> (raw)
In-Reply-To: <20170408191959.GA7541@breton.holly.idiocy.org>
On Sat, Apr 08, 2017 at 08:19:59PM +0100, Alan Third wrote:
> On Sat, Apr 08, 2017 at 08:47:25AM -0700, Aaron Jensen wrote:
> > On Sat, Apr 8, 2017 at 12:37 AM, YAMAMOTO Mitsuharu
> > <mituharu@math.s.chiba-u.ac.jp> wrote:
> > >
> > > Probably "fork" copies some GUI resources. That would also explain
> > > why the performance is worse on the Mac port, where each frame
> > > allocates an extra NSWindow for overlaying.
> > >
> > > It becomes much faster and seemingly unaffected by the frame size if
> > > you comment out "#undef HAVE_WORKING_VFORK" and "#define vfork fork"
> > > in src/conf_post.h. But I'm not sure if it is safe.
> >
> > Wow, that does make a big difference. The comment says that Emacs
> > hangs when evaluating:
> >
> > (make-comint "test0" "/nodir/nofile" nil "")
> >
> > But I can not reproduce that currently with vfork.
I can’t reproduce a hang with that command either.
> > I do not understand the second comment: "Also, setsid is not
> > allowed in the vfork child's context as of Darwin 9/Mac OS X
> > 10.5."
>
> It looks to me like we could replace the call to setsid with
>
> setpgid (0, 0);
>
> for Darwin builds.
No, forget that. It doesn’t do the same thing at all.
If you run Emacs, then
M‐x ansi-term RET RET
You should get a shell prompt. Using fork/setsid, your shell will be
able to do job control, but using vfork it can’t. You can test this by
typing the `bg` command. Zsh (and I assume bash, etc.) responds by
telling you either there are no jobs, or that the shell has no job
control.
We could work around this in a rather ugly manner by doing something like:
#ifdef DARWIN_OS
if (pty_flag)
pid = fork ();
else
pid = vfork ();
#else
pid = vfork ();
#endif
which would use fork where we’re expecting to run setsid, and vfork
otherwise.
--
Alan Third
next prev parent reply other threads:[~2017-04-09 13:01 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-08 6:25 bug#26397: 25.1; call-process slow on macOS and slower on larger frames Aaron Jensen
2017-04-08 7:37 ` YAMAMOTO Mitsuharu
2017-04-08 15:47 ` Aaron Jensen
2017-04-08 19:19 ` Alan Third
2017-04-09 13:01 ` Alan Third [this message]
2017-04-09 15:07 ` Aaron Jensen
2017-04-09 19:18 ` bug#26397: [PATCH] Use vfork if possible on Darwin (bug#26397) Alan Third
2017-04-09 20:32 ` Andreas Schwab
2017-04-09 21:34 ` Alan Third
2017-04-09 23:46 ` YAMAMOTO Mitsuharu
2017-04-10 0:06 ` Aaron Jensen
2017-04-10 1:11 ` YAMAMOTO Mitsuharu
2017-04-10 4:13 ` Aaron Jensen
2017-04-10 15:42 ` bug#26397: [PATCH v2] " Alan Third
2017-04-11 7:06 ` YAMAMOTO Mitsuharu
2017-04-18 2:29 ` Aaron Jensen
2017-04-18 10:48 ` Alan Third
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=20170409130155.GA59432@breton.holly.idiocy.org \
--to=alan@idiocy.org \
--cc=26397@debbugs.gnu.org \
--cc=aaronjensen@gmail.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.
Code repositories for project(s) associated with this external index
https://git.savannah.gnu.org/cgit/emacs.git
https://git.savannah.gnu.org/cgit/emacs/org-mode.git
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.