>Number:         9979
>Category:       kern
>Synopsis:       uvm(9) confusion and missing descriptions
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          doc-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Apr 25 04:06:00 PDT 2000
>Closed-Date:
>Last-Modified:
>Originator:     matthew green
>Release:        <NetBSD-current source date>today
>Organization:
people's front against (bozotic) www (softwar foundation)
>Environment:
	
System: NetBSD fish-dances.eterna.com.au 1.4X NetBSD 1.4X (_fish_) #20: Sun Apr 16 04:27:56 EST 2000 mrg@fish-dances.eterna.com.au:/var/_fish_ i386


>Description:

	while reading some kernel code, i noticed that the calls:
		uvm_km_suballoc()
		uvm_km_free()
		uvm_km_free_wakeup()
	are given prototypes in uvm.9 but there is no description of what
	these calls do.

	also, while attempting to understand the Alpha bus_dma
	implementation, i noticed that it uses uvm_km_valloc() to
	allocate kernel memory without actually allocating or mapping
	any pages.  the description for this is not quite clear on
	this and that it can be used to allocate some space in the
	kernel map for someone else to load pages into (eg, the
	bus_dmamem_map() function :-)

>How-To-Repeat:

	see above.
>Fix:

	write the descriptions and expand the valloc() one.  this PR
	is mostly a place holder so that myself or someone else doesn't
	forget to do it eventually.
>Release-Note:
>Audit-Trail:
>Unformatted: