Re: SMP linux help

Riley Williams (rhw@MemAlpha.CX)
Sat, 4 Sep 1999 23:17:54 +0100 (GMT)


Hi Nate.

> I have been wondering about the locking stuff for a while too.
> These are probably dumb questions but my OS terminology is not
> what it could be. (Is there a good reference somewhere?)

> * Does "lock the kernel" mean "prevent anyone else from
> executing any kernel code"?

I'm not 100% certain, but my understanding is that "lock the kernel"
means "prevent anybody else ON THIS PROCESSOR from executing any
kernel code", which is slightly different from your definition.

> * If so, what happens if some other CPU is already inside the
> kernel? Is there some mechanism to stop the other CPU??

Presumably not applicable - I believe that's what spinlocks are for,
and is also why both are needed in certain parts of the kernel.

Best wishes from Riley.

+----------------------------------------------------------------------+
| There is something frustrating about the quality and speed of Linux |
| development, ie., the quality is too high and the speed is too high, |
| in other words, I can implement this XXXX feature, but I bet someone |
| else has already done so and is just about to release their patch. |
+----------------------------------------------------------------------+
* ftp://ftp.MemAlpha.cx/pub/rhw/Linux
* http://www.MemAlpha.cx/Linux/

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/