Re: vmalloc cached space..

["Maciej W. Rozycki" <macro@ds2.pg.gda.pl>]

On Wed, 16 Apr 2003, Ralf Baechle wrote:

> > 2. i should use vmalloc_prot (size, PAGE_KERNEL_UNCACHED) in umap.c.
> 
> Uncached memory access is rarely necessary and so _extremly_ slow that it
> should be avoided at almost any price.  Maybe you should describe what
> you're trying to achieve, then let's see if there's a better suggestion
> we can make.

 In particular using cached accesses for stores and then doing writebacks
(plus invalidates if necessary) is still faster with WB caches. 

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: macro@ds2.pg.gda.pl, PGP key available        +