Re: lock_kernel

[John Levon <moz@compsoc.man.ac.uk>]

On Sat, 19 May 2001, siva prasad wrote:

> Hi guys
> when the macro lock_kernel is defined as 
> do{ } while(0)
> and when it comes 'out' immediately('cos the condition
> is false by having specified 0) from the flow of
> control what is the rational behind using it?
> thanks

It is only defined like that on single-processor builds.
lock_kernel() is needed in some places to provide mutual
exclusion on SMP (multi-processor) systems. Have a look
at the other definition.

john

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