RE: [rtl] The HLT instruction

[Nathan Harris <nathan@geodetic.com>]

Many real time OS's (if not all) use the HLT instruction on Intel CPUs
to conserve power.  This "hardware sleep" just effects the CPU and for
all intents the wake up is instaneous.  I'm not sure of the exact
wake-up time, but I believe it is much less than a CPU clock cycle.

-Nathan
mailto:nathan@geodetic.com
http://www.geodetic.com/nathan


-----Original Message-----
From: Daniele Lugli [mailto:danlugli@inrete.it]
Sent: Thursday, October 01, 1998 4:38 AM
To: rtl@rtlinux.cs.nmt.edu
Subject: Re: [rtl] The HLT instruction


PayPC System Mail Subscriber wrote: 
Nathan Harris said in [rtl] The HLT instruction at 30/Sep/1998 (Wed)
00:26:55. 
> Does RTLinux and/or Linux use the HLT instruction during the OS idle 
I can speak for Linux.... it uses HLT when no tasks are in "ready"
state. 
I don't have rt-linux, but I doubt that aspect was changed. 
 
I *hope* it has been changed. A real time system should *not* be put to
sleep to save power! 
Daniele Lugli 
  
--- [rtl] ---
To unsubscribe:
echo "unsubscribe rtl" | mail majordomo@rtlinux.cs.nmt.edu OR
echo "unsubscribe rtl <Your_email>" | mail majordomo@rtlinux.cs.nmt.edu
----
For more information on Real-Time Linux see:
http://www.rtlinux.org/~rtlinux/