Messages in this thread |  | | | Date | Mon, 4 Oct 1999 19:39:01 -0700 (PDT) | | From | "B. James Phillippe" <> | | Subject | RE: SMP system panic with down/up calls for locking. Need help o n as sembly compiling. |
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On Mon, 4 Oct 1999, WANG,YIDING (HP-SanJose,ex1) wrote:
> 1, I don't have down/up in ISR routine. System panic during making file
"interrupt-time" doesn't just mean ISR routine, it means anything which happens outside of the context of a process. In kernel code, this is almost everything outside of a system call*.
To demonstrate, call in_interrupt() before you call down() and if the return value is true, printk some message instead of downing the semaphore. That's not normal practice, but it's a quick and dirty way to test whether or not this is your problem.
*one exception is the tq_scheduler task queue.
BTW, showing what message is printed with the panic would be very helpful..
> 2, The locking rquired in driver is for : > a) Driver local queue, say free ccb list. When on cpu is trying to > put a ccb back to freelist and another is getting a free ccb, it > requires lock.
Use a spinlock for this one.
-bp -- # bryan at terran dot org # http://www.terran.org/~bryan
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