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From: John Baldwin <jhb@freebsd.org>
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Cc: Jaakko Heinonen <jh@freebsd.org>, phk@freebsd.org
Subject: Re: [patch] extending alloc_unr(9) to allocate specific unit numbers
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On Saturday 19 June 2010 11:48:22 am Jaakko Heinonen wrote:
> 
> Hi,
> 
> I wrote a patch to extend the kernel unit number allocator for
> allocating specific unit numbers. The patch adds a new function
> alloc_unr_specific() which returns the requested unit number if it is
> free and -1 if the number is already allocated or out of the range.
> Unlike alloc_unr(), alloc_unr_specific() may allocate memory and thus
> sleep.
> 
> The patch is here:
> 
> 	http://people.freebsd.org/~jh/patches/alloc_unr_specific.diff
> 
> I think that this functionality has been requested by some people.
> Reviews/comments?
> 
> As an example here is md(4) converted to use
> alloc_unr() / alloc_unr_specific():
> 
> 	http://people.freebsd.org/~jh/patches/md-alloc_unr.diff

This sounds useful to me.  Perhaps ask phk@?

-- 
John Baldwin