LinuxQuestions.org
Visit Jeremy's Blog.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices

Reply
 
Search this Thread
Old 03-16-2009, 04:54 AM   #1
aixilin
LQ Newbie
 
Registered: Aug 2008
Posts: 28

Rep: Reputation: 15
A question about real time linux


Hi, all,
I am a newbie on RTAI. If I have two task, one is periodic task which has lower priority and the other one is aperiodic task which has higher priority, and the aperiodic task need more process time than periodic task, would the periodic task was blocked by aperiodic task?
If periodic task was blocked, so it is not periodic anymore because it can not get period time from cpu.

Any help is appreciate.
 
Old 03-16-2009, 07:36 AM   #2
xodr
LQ Newbie
 
Registered: May 2008
Posts: 4

Rep: Reputation: 0
Yes, the lower prio task would be blocked by the higher prio task until the higher prio task is finished (assuming priority based scheduling with no resource sharing).

The scenario you describe is a missed deadline. The task is defined as a periodic task but it can't complete before the next period due to high CPU load. To fix this you must either optimize your schedule, tasks or scheduling algo. in some way to meet the timing requirements or upgrade your HW.

If the aperiodic task's deadline is not a hard one but the periodic task's deadline is, you may consider lowering aperiodic task's prio.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Question about real-time web delivery karozans Linux - General 1 01-09-2009 05:23 PM
Real Time Clock & Real Time Timer jiramak Linux - Newbie 1 09-05-2007 06:43 PM
LXer: Real-time garbage collection with Real-time Java LXer Syndicated Linux News 0 05-05-2007 12:16 PM
LXer: Real-time Linux gains real-time JVM LXer Syndicated Linux News 0 10-12-2006 10:54 AM
LXer: Real Time Coming to Linux Real Soon LXer Syndicated Linux News 1 08-23-2006 06:30 PM


All times are GMT -5. The time now is 10:08 PM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration