Re: [v3 9/9] s390: teach platforms not to zero struct pages memory

From: Pasha Tatashin
Date: Mon May 15 2017 - 14:24:23 EST


Hi Heiko,

Thank you for looking at this patch. I am worried to make the proposed change, because, as I understand in this case we allocate memory not for "struct page"s but for table that hold them. So, we will change the behavior from the current one, where this table is allocated zeroed, but now it won't be zeroed.

Pasha


If you add the hunk below then this is

Acked-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>

diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index ffe9ba1aec8b..bf88a8b9c24d 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -272,7 +272,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
if (pte_none(*pt_dir)) {
void *new_page;
- new_page = vmemmap_alloc_block(PAGE_SIZE, node, true);
+ new_page = vmemmap_alloc_block(PAGE_SIZE, node, VMEMMAP_ZERO);
if (!new_page)
goto out;
pte_val(*pt_dir) = __pa(new_page) | pgt_prot;