Rik van Riel wrote:
>
> Hi,
>
> the attached patch contains the code for a very low overhead
> fair share scheduler. Unfortunately it hangs on taking locks
> in the recalculation code :(
>
> I'm somewhat amazed by why it hangs and interested in any
> explanations...
>
> cheers,
>
> Rik
> --
> The Internet is not a network of computers. It is a network
> of people. That is its real strength.
>
> + write_lock(&tasklist_lock);
> + printk(" . . .\n");
Rik,
The problem might be the write_lock(&tasklist_lock). Interrupt handlers
sometimes call kernel functions that would require a lock on
tasklist_lock. If that interrupt happens during the time you hold write
lock on tasklist_lock, a deadlock would happen.
Try using write_lock_irq() to fix that problem.
BTW, I really think interrupt handlers acquiring the same locks which
can be acquired by processes is a *BIG* problem in Linux. We should fix
this problem. Unfortunately I am not familiar with Linux kernel well
enough to offer a solution.
Jun
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This archive was generated by hypermail 2b29 : Fri Mar 31 2000 - 21:00:23 EST