Re: [DOC PATCH] semaphore documentation

[David Woodhouse <dwmw2@infradead.org>]

On Sat, 2008-04-12 at 08:12 -0600, Matthew Wilcox wrote:
> As I wrote in one of the comments, we have places in the kernel which
> know that even though they're in a non-sleeping context, there is at
> least one more token left in the semaphore.  One place this bit me was
> in start_kernel().  We disable interrupts and then call lock_kernel()
> which calls down().  Since we're in start_kernel(), we know there's
> nothing else running and this is perfectly safe.  But a might_sleep()
> would warn bogusly.

I would have thought they'd use down_trylock() in that case.

-- 
dwmw2