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Doubts about timers in linux kernel


 
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# 1  
Old 02-22-2009
Doubts about timers in linux kernel

Hi ,


I am trying to learn timers in linux kernel. I am trying to write a program where I can configure a timer to tick in every 5 seconds and a function should thus exicute in every five seconds. I tried one program with the help of linux/timer.h headerfile but I couldnt get the delay right and my function exicutes only once.That is my timer acts like a single shot timer. How can I make the timer multi slot (not single slot , that is what I am trying to say), Plus How can I calculate the time delay in linux kernel. What is jiffies infact. What is the value of 1 jiffy in seconds . Hoping for help

Jayanth. S
# 2  
Old 02-23-2009
(moved to C programming forum).

Please post your existing code.
# 3  
Old 02-23-2009
A good place to start would be the alarm function (man alarm). alarm sends a signal to the process every so many seconds so you need to write a handler to trap that signal and call another function from within it. And post your code also.
# 4  
Old 02-24-2009
Thanks for the reply. But I want a timer in kernel space. We cannot use alarm functions in kernel space. That is why I posted this in linux forum. I want to user add_timer() setup_timer functions in linux/timer.h. I tried in vain . I could only create a single shot alarm .How can I take a multislot alarm in kernel.
# 5  
Old 02-24-2009
Quote:
Originally Posted by iamjayanth
Thanks for the reply. But I want a timer in kernel space. We cannot use alarm functions in kernel space. That is why I posted this in linux forum. I want to user add_timer() setup_timer functions in linux/timer.h. I tried in vain . I could only create a single shot alarm .How can I take a multislot alarm in kernel.
No that won't work as I missed the part about kernel space timer...the alarm/pause calls will work only in the context of a user process.

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