Subject: Re: Yet more Device Properties
To: None <eeh@netbsd.org, enami@but-b.or.jp>
From: None <eeh@netbsd.org>
List: tech-kern
Date: 02/22/2001 22:54:15
	> Why isn't SLIST appropriate?  Removing properties is not a very
	> common operation.

	With SLIST, dev_delprop will need to traverse the list twice (once to
	locate the property by name and once to remove it).  Why not just use
	LIST?

This is the standard size/performance tradeoff.  While
there may be thousands of properties on various nodes
in the device tree, I doubt that any particular device
will have more than about 20 properties.  

Speed is not a major consideration in the current 
device properties implementation.  If it were, I
would be using a tree or hash table instead of a
linked list.  If device properties are used enough 
to have a measurable effect on performance (through
profiling), the routines could be rewritten to
be much more efficient and use O(log n) or
O(1) data structures.  But since they will be used
primarily during device probing, any such overhead
should be dwarfed by the delays already in the driver
initialization code.

Eduardo