Re: [PATCH,RFC] Add __GFP_ZERO to GFP_LEVEL_MASK

[Andrew Morton <akpm@osdl.org>]

On Fri, 13 Oct 2006 15:00:22 -0600
corbet@lwn.net (Jonathan Corbet) wrote:

> Andrew Morton <akpm@osdl.org> wrote:
> 
> > It would be a bit odd to pass __GFP_ZERO into the slab allocator.  Slab
> > doesn't need that hint: it has its own ways of initialising the memory.
> > 
> > What is the callsite?
> 
> It's vmalloc_user(), which does this:
> 
>   ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
> 

oic, yes, that was a recent change.

I guess this will do the trick?


diff -puN mm/vmalloc.c~vmalloc-dont-pass-__gfp_zero-to-slab mm/vmalloc.c
--- a/mm/vmalloc.c~vmalloc-dont-pass-__gfp_zero-to-slab
+++ a/mm/vmalloc.c
@@ -428,8 +428,11 @@ void *__vmalloc_area_node(struct vm_stru
 	if (array_size > PAGE_SIZE) {
 		pages = __vmalloc_node(array_size, gfp_mask, PAGE_KERNEL, node);
 		area->flags |= VM_VPAGES;
-	} else
-		pages = kmalloc_node(array_size, (gfp_mask & ~__GFP_HIGHMEM), node);
+	} else {
+		pages = kmalloc_node(array_size,
+				(gfp_mask & ~(__GFP_HIGHMEM | __GFP_ZERO)),
+				node);
+	}
 	area->pages = pages;
 	if (!area->pages) {
 		remove_vm_area(area->addr);
_



(hmm, __vmalloc_area_node and __vmalloc_node are mutually recursive. ick.)