Re: SMP DEBUG_SPINLOCKS

From: Ralf Baechle (ralf@uni-koblenz.de)
Date: Thu May 18 2000 - 18:32:34 EST


On Thu, May 18, 2000 at 10:20:42AM -0700, George Anzinger wrote:

> be a lot of code in the same file to back up this define, but it is all
> for UP or at least is not active for SMP.) The actual code emitted by
> the ndef case is also NOT useful spin lock code for an SMP case while
> the SMP case code looks like it really does something.

The uniprocessor kernel doesn't need spinlocks to protect anything against
access by other processors, so those spinlocks are expaneded into nothing
where do { } while(0) is equivalent to nothing. As a consequene the
*_irq and *_irqsave functins also expand just into interrupt fiddling
code on UP.

  Ralf

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