Hi Istvan,

I remember trying the watchdog from the API in Java and when it died
it seemed to take the parent process down with it (the Java App).  I
think it has to do with this:

	        kill(0, SIGTERM); csoundSleep(1500);
	        kill(0, SIGKILL); csoundSleep(1500);

and passing in 0 to kill the process group as opposed to the
individual process.  Am in incorrect in this?  Is there a way to
guarantee the parent process won't die?

steven


On 1/25/06, Istvan Varga <istvan_v@fibermail.hu> wrote:
> --sched uses the SCHED_RR scheduling policy which allows Csound to
> use up to 100% of CPU time, regardless of any other applications
> running. Setting a nice level only changes the weighting of CPU time
> between applications running at the same time, while a process
> running with a real-time scheduling policy (SCHED_RR or SCHED_FIFO)
> can take away the CPU from other "normal" processes (i.e. those with
> a SCHED_OTHER policy) at any time, even locking up the system and
> making it not respond to user input. Thus, --sched is more powerful
> than renice, but is also dangerous and normally requires root
> privileges.
>
> The --sched option also has some parameters:
>
>   --sched=N
>
>     if N is positive, uses SCHED_RR with a priority of N (1 to 99).
>     If N is zero or negative, uses SCHED_OTHER with a nice level of
>     N (-20 to 0), but still locks memory.
>
>   --sched=N,MAXCPU,TIME
>
>     same as above, but also enables the use of an experimental
>     "watchdog" thread that will terminate Csound if the CPU usage
>     exceeds MAXCPU percents over a period of TIME seconds.
>     This can save some reboots or uses of Alt+SysRq key combinations
>     that may otherwise be needed when the CPU is maxed out.
>     Example: --sched=95,97,10
>
> On Wednesday 25 January 2006 19:11, David Akbari wrote:
>
> > Since I know some people who lurk the list are savvy with computer
> > science I figured I'd ask the following question:
> >
> > What is the difference between using the --sched flag on the
> > commandline vs. not using --sched and instead using renice for the
> > running Csound process ? (Other than the fact that --sched locks
> > memory)
> >
> > something like
> >
> > % sudo renice -20 -p <csound pid here>
> >
> > I'm asking this in the abstract, I do not mean to pose questions that
> > would result in benchmarks - I am merely curious.
> --
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