[Bug 87891] New: kernel BUG at mm/slab.c:2625!

[Kirill A. Shutemov]

On Tue, Nov 11, 2014 at 04:49:13PM -0800, Andrew Morton wrote:
> On Tue, 11 Nov 2014 18:36:28 -0600 (CST) Christoph Lameter <cl at linux.com> wrote:
> 
> > On Tue, 11 Nov 2014, Andrew Morton wrote:
> > 
> > > There's no point in doing
> > >
> > > 	#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
> > >
> > > because __GFP_DMA32|__GFP_HIGHMEM are already part of ~__GFP_BITS_MASK.
> > 
> > ?? ~__GFP_BITS_MASK means bits 25 to 31 are set.
> > 
> > __GFP_DMA32 is bit 2 and __GFP_HIGHMEM is bit 1.
> 
> Ah, yes, OK.
> 
> I suppose it's possible that __GFP_HIGHMEM was set.
> 
> do_huge_pmd_anonymous_page
> ->pte_alloc_one
>   ->alloc_pages(__userpte_alloc_gfp==__GFP_HIGHMEM)

do_huge_pmd_anonymous_page
 alloc_hugepage_vma
  alloc_pages_vma(GFP_TRANSHUGE)

GFP_TRANSHUGE contains GFP_HIGHUSER_MOVABLE, which has __GFP_HIGHMEM.

-- 
 Kirill A. Shutemov