Zone memory for UMA

John Baldwin jhb at freebsd.org
Sat Jan 20 15:54:24 UTC 2007


On Thursday 18 January 2007 08:55, Randall Stewart wrote:
> Hi all:
> 
> Query (with flame suit in place :-D)
> 
> Currently the UMA zone's will hold all memory
> in them until .. well until the page deamon
> runs.. or so the "zone_drain()" comment says.. but
> I can't find that connection either. So I guess
> not at all :-0

uma_reclaim() drains all zones when it is called.  It is called by the
pagedaemon when it is woken up to free some memory.

> Should we think about adding some sort of garbage
> collector thread.. that could hang around slowly and
> periodically look for a zone with large numbers of free
> pages... and then drain that zone?

pagedaemon is a sort of GC thread, but it kicks in whenever the system
is low on memory and asks other subsystems like UMA to free up some
memory.

-- 
John Baldwin


More information about the freebsd-current mailing list