Subject: Re: kernel map entry merging and PR 24039
To: None <matt@3am-software.com>
From: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
List: tech-kern
Date: 02/11/2004 16:51:21
hi,

> >maybe you can
> >         1. uvm_map_prepare
> >         2. allocate pages
> >         3. uvm_map_enter
> >so that you don't need to do uvm_unmap.
> 
> Or add an UVM_KMF_NOMERGE flag and pass that to uvm_map.  This
> will prevent a merge on the VA region just mapped.  Then after
> successfully getting the pages (at a point failure is no longer
> possible), do a uvm_map_compress(map, kva, size) which clears the
> UVM_KMF_NOMERGE flag and then tries to do the map entry merging
> at that point.  If it can't, no problem.

i don't think it's better because it needs to lookup entry twice.

YAMAMOTO Takashi