Re: igc, macOS avoiding signals

[Eli Zaretskii]

> Date: Sat, 28 Dec 2024 19:15:26 +0000
> From: Pip Cet <pipcet@protonmail.com>
> Cc: spd@toadstyle.org, gerd.moellmann@gmail.com, emacs-devel@gnu.org
> 
> "Eli Zaretskii" <eliz@gnu.org> writes:
> 
> > Ah, okay.  I note that if we'd block signals when calling MPS and
> > unblock on exit, then these delays couldn't have happened, AFAIU.
> 
> We can't do so for SIGSEGV calling into MPS, so this wouldn't fix all
> cases.

We don't need to block SIGSEGV (or any other fatal signal).  We only
need to block SIGPROF, SIGALRM and SIGCHLD.

> Blocking signals around mps_alloc slows down (make-list 1000000
> nil) by a factor of about 5 (on current GNU/Linux; possibly
> significantly more on other operating systems).

No, I think only GNU/Linux is affected.

You are saying that sigblock is very expensive?  Can you measure it?