On Wed 16-08-17 15:07:05, Laura Abbott wrote:
> Commit 19809c2da28a ("mm, vmalloc: use __GFP_HIGHMEM implicitly")
> added use of __GFP_HIGHMEM for allocations. vmalloc_32 may use
> GFP_DMA/GFP_DMA32 which does not play nice with __GFP_HIGHMEM
> and will drigger a BUG in gfp_zone. Only add __GFP_HIGHMEM ifs@drigger@trigger@ > we aren't using GFP_DMA/GFP_DMA32. > > Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1482249 > Fixes: 19809c2da28a ("mm, vmalloc: use __GFP_HIGHMEM implicitly") > Signed-off-by: Laura Abbott <[email protected]> Sorry about that. My fault! I have completely missed that VM_BUG_ON. I was double checking that GFP_DMA|__GFP_HIGHMEM works as inteded which is the case because DMA has always a preference. I have reached the same conclusion for GFP_DMA32 but now that I am looking at the GFP_ZONE_TABLE again I was wrong because we would end up in ZONE_DMA AFAICS because bit 1 wouldn't be set. Acked-by: Michal Hocko <[email protected]> Thanks! > --- > mm/vmalloc.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 8698c1c86c4d..a47e3894c775 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -1671,7 +1671,10 @@ static void *__vmalloc_area_node(struct vm_struct > *area, gfp_t gfp_mask, > struct page **pages; > unsigned int nr_pages, array_size, i; > const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO; > - const gfp_t alloc_mask = gfp_mask | __GFP_HIGHMEM | __GFP_NOWARN; > + const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN; > + const gfp_t highmem_mask = (gfp_mask & (GFP_DMA | GFP_DMA32)) ? > + 0 : > + __GFP_HIGHMEM; > > nr_pages = get_vm_area_size(area) >> PAGE_SHIFT; > array_size = (nr_pages * sizeof(struct page *)); > @@ -1679,7 +1682,7 @@ static void *__vmalloc_area_node(struct vm_struct > *area, gfp_t gfp_mask, > area->nr_pages = nr_pages; > /* Please note that the recursion is strictly bounded. */ > if (array_size > PAGE_SIZE) { > - pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM, > + pages = __vmalloc_node(array_size, 1, nested_gfp|highmem_mask, > PAGE_KERNEL, node, area->caller); > } else { > pages = kmalloc_node(array_size, nested_gfp, node); > @@ -1700,9 +1703,9 @@ static void *__vmalloc_area_node(struct vm_struct > *area, gfp_t gfp_mask, > } > > if (node == NUMA_NO_NODE) > - page = alloc_page(alloc_mask); > + page = alloc_page(alloc_mask|highmem_mask); > else > - page = alloc_pages_node(node, alloc_mask, 0); > + page = alloc_pages_node(node, alloc_mask|highmem_mask, > 0); > > if (unlikely(!page)) { > /* Successfully allocated i pages, free them in > __vunmap() */ > @@ -1710,7 +1713,7 @@ static void *__vmalloc_area_node(struct vm_struct > *area, gfp_t gfp_mask, > goto fail; > } > area->pages[i] = page; > - if (gfpflags_allow_blocking(gfp_mask)) > + if (gfpflags_allow_blocking(gfp_mask|highmem_mask)) > cond_resched(); > } > > -- > 2.13.0 > -- Michal Hocko SUSE Labs
