Re: Weirdness with suspending jobs in 2.6.9-rc3

[Petri Kaukasoina <kaukasoi@elektroni.ee.tut.fi>]

On Mon, Oct 11, 2004 at 08:45:12PM -0700, Andrew Morton wrote:
> Petri Kaukasoina <kaukasoi@elektroni.ee.tut.fi> wrote:
> >
> > On Mon, Oct 11, 2004 at 01:55:05PM -0700, Roland McGrath wrote:
> > > > wait4(-1073750280, NULL, 0, NULL)       = -1 ECHILD (No child processes)
> > > 
> > > That is a clearly bogus argument.
> > 
> > Hi. I see it too:
> > 
> > wait4(-1073750328, NULL, 0, NULL)       = -1 ECHILD (No child processes)
> > 
> > But the whole problem goes away if I switch CONFIG_REGPARM off. To reproduce
> > it needs CONFIG_REGPARM=y.
> > 
> 
> Interesting.
> 
> What command are you actually running to demonstrate this?  Full details,
> please.

First 'make' while the Makefile is this

all:
	sleep 40
	echo Hi
	sleep 5

and then in a different window 'ps ux' and then 'strace -p PID'. If
CONFIG_REGPARM if off then the strace starts:

Process 324 attached - interrupt to quit
wait4(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 325
--- SIGCHLD (Child exited) @ 0 (0) ---
sigreturn()                             = ? (mask now [])
write(1, "echo Hi\n", 8)                = 8

if CONFIG_REGPARM=Y then it starts:

Process 14226 attached - interrupt to quit
wait4(-1073750328, NULL, 0, NULL)       = -1 ECHILD (No child processes)
write(2, "make: *** ", 10)              = 10
write(2, "wait: No child processes", 24) = 24
write(2, ".  Stop.\n", 9)               = 9
write(2, "make: ", 6)                   = 6