Re: spin_locks without smp.

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Fri Jan 10 2003 - 08:23:56 EST


On Fri, 2003-01-10 at 11:45, William Lee Irwin III wrote:
> On Fri, Jan 10, 2003 at 12:42:34PM +0100, Maciej Soltysiak wrote:
> > while browsing through the network drivers about the etherleak issue i
> > found that some drivers have:
> > #ifdef CONFIG_SMP
> > spin_lock_irqsave(...)
> > #endif
> > and some just:
> > spin_lock_irqsave(...)
> > or similar.
> > Which version should be practiced? i thought spinlocks are irrelevant
> > without SMP so we should use #ifdef to shorten the execution path.
>
> Buggy on preempt. Remove the #ifdef

And render the driver unusable. Very clever. How about understanding *why*
something was done first 8)

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