When populating mappings backed by contiguous memory allocations (VM_CONTIG), use the preallocated pages instead of allocating new.
Signed-off-by: Mike Kravetz <[email protected]> --- mm/memory.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index a728bed16c20..fbef78d07cf3 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3100,7 +3100,18 @@ static int do_anonymous_page(struct vm_fault *vmf) /* Allocate our own private page. */ if (unlikely(anon_vma_prepare(vma))) goto oom; - page = alloc_zeroed_user_highpage_movable(vma, vmf->address); + + /* + * In the special VM_CONTIG case, pages have been pre-allocated. So, + * simply grab the appropriate pre-allocated page. + */ + if (unlikely(vma->vm_flags & VM_CONTIG)) { + VM_BUG_ON(!vma->vm_private_data); + page = ((struct page *)vma->vm_private_data) + + ((vmf->address - vma->vm_start) / PAGE_SIZE); + } else { + page = alloc_zeroed_user_highpage_movable(vma, vmf->address); + } if (!page) goto oom; -- 2.13.6
