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lock_kernel() ...

Posted on 2001-08-28
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Last Modified: 2013-12-26
Hi, I'm Salvatore , from Italy.
My question:
How can i lock a my function from time-sharing-scheduling?
I've tried including smp_lock.h that contain lock_kernel
& unlock_kernel() and calling it.
gcc goals but i think that it does not work.

I'm writing some programs about semaphore and shared memory (exactly for resolving problem of reader's and writer's, producer & consumer).
For debug i use some printf and it happen strange things. Printf is buffered and using a fork i found a father's printf in the system calls of the process created.
(see strace -ff -T -tt exe).
Than i'm writing a function (print2debug()) that lock
the kernel so all state(variables, contest in which printf appear) are ok while execute the debug function.
I thank you for any reply!!! GoodBye from Naples.
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Question by:slionetti
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chris_calabrese earned 50 total points
ID: 6437040
First, you can use fflush() to flush the printf buffer.

Meanwhile, the lock_kernel() stuff is probably only for use within the kernel.

I'm guessing this is a homework problem, so you're actually first supposed to write the semaphore stuff yourself.  But if not, see the man pages for semget(), semop() and semctl().
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by:nhuanvn
ID: 6443254
I don't think that you can lock the kernel in Unix user
space. In some realtime OSs like VxWorks [www.windrivers.com] they provides taskLock() that can
serve your question. You can use semaphores instead in
Unix, but it is of course not strong enough as kernel_lock
feature
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by:chris_calabrese
ID: 6444526
You can't lock the kernel in user space.  The include files have both the user- and kernel-space prototypes, though.
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by:tfewster
ID: 8191570
No comment has been added lately, so it's time to clean up this Topic Area.
I will leave a recommendation for this question in the Cleanup topic area as follows:

- Answered by chris_calabrese

Please leave any comments here within the next 7 days

PLEASE DO NOT ACCEPT THIS COMMENT AS AN ANSWER !

tfewster
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Expert Comment

by:modulo
ID: 8241217
Finalized as proposed

modulo

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