Re: Change in process.c

[Sam Steingold <sds@gnu.org>]

> * Richard Stallman <ezf@tah.bet> [2007-03-26 19:13:42 -0400]:
>
> What was the reason for moving the first sleep before the first wait3
> call?  It looks like that will force a one-second delay even
> in cases where it would succeed straightaway.
>
> Using usleep would reduce that problem to an acceptable level,
> but I am not sure all systems have usleep.  So it is risky
> to make that change.
>
> What's the issue here?

this has been discussed here:
http://thread.gmane.org/gmane.emacs.devel:67722

I have been observing the following behavior:
emacs hangs in sigchld_handler waiting for the child process to
terminate.
the system stops responding, loadavg goes to 5-8(!), CPU is 100% busy.
this lasts for ~10 seconds.
this happens on M-c compile and when I click on a URL (it is passed to
an existing Firefox).

the sleep (and the most recent usleep) patch fixes the problem for me.
this may be linux-specific - I have to defer to kernel experts on that.

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