SIGPWR signal in system v

[Oisin Hurley]

Does anybody out there have information on the SYS V SIGPWR signal? The man
says that this signal occurs if there's a power failure. I have a couple of
questioned which I haven't been able to answer myself:

1. When power goes, is this signal sent to every process currently running?

2. How far does the power have to drop before the signal is activated?

3. How long does the power have to stay at that level to ensure activation?
	(how about transients, etc.)

4. Is the signal generated on the mboard or is there a line from the psu?

5. Has anybody used it - is it useful? Is there enough time to sync disks
   upon receipt of SIGPWR (I presume there's hardly time for anything)?
   
6. Why is it there?


Any help would be much appreciated.
thanks in advance
	O[-<

---
ombhurley at cs.tcd.ie
Oisin Hurley, Dept. of Comp. Sci., TCD, Dublin 2, Ireland
---