From dbc8358c72373daa4f37b7e233fecbc47105fe54 Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Fri, 12 Dec 2014 16:55:55 -0800 Subject: [PATCH] mm/nommu: use alloc_pages_exact() rather than its own implementation do_mmap_private() in nommu.c try to allocate physically contiguous pages with arbitrary size in some cases and we now have good abstract function to do exactly same thing, alloc_pages_exact(). So, change to use it. There is no functional change. This is the preparation step for support page owner feature accurately. Signed-off-by: Joonsoo Kim Cc: Mel Gorman Cc: Johannes Weiner Cc: Minchan Kim Cc: Dave Hansen Cc: Michal Nazarewicz Cc: Jungsoo Son Cc: Ingo Molnar Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/nommu.c | 33 +++++++++++---------------------- 1 file changed, 11 insertions(+), 22 deletions(-) diff --git a/mm/nommu.c b/mm/nommu.c index cd519e1cd8a7..b51eadf6d952 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1149,8 +1149,7 @@ static int do_mmap_private(struct vm_area_struct *vma, unsigned long len, unsigned long capabilities) { - struct page *pages; - unsigned long total, point, n; + unsigned long total, point; void *base; int ret, order; @@ -1182,33 +1181,23 @@ static int do_mmap_private(struct vm_area_struct *vma, order = get_order(len); kdebug("alloc order %d for %lx", order, len); - pages = alloc_pages(GFP_KERNEL, order); - if (!pages) - goto enomem; - total = 1 << order; - atomic_long_add(total, &mmap_pages_allocated); - point = len >> PAGE_SHIFT; - /* we allocated a power-of-2 sized page set, so we may want to trim off - * the excess */ + /* we don't want to allocate a power-of-2 sized page set */ if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) { - while (total > point) { - order = ilog2(total - point); - n = 1 << order; - kdebug("shave %lu/%lu @%lu", n, total - point, total); - atomic_long_sub(n, &mmap_pages_allocated); - total -= n; - set_page_refcounted(pages + total); - __free_pages(pages + total, order); - } + total = point; + kdebug("try to alloc exact %lu pages", total); + base = alloc_pages_exact(len, GFP_KERNEL); + } else { + base = (void *)__get_free_pages(GFP_KERNEL, order); } - for (point = 1; point < total; point++) - set_page_refcounted(&pages[point]); + if (!base) + goto enomem; + + atomic_long_add(total, &mmap_pages_allocated); - base = page_address(pages); region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; region->vm_start = (unsigned long) base; region->vm_end = region->vm_start + len; -- 2.20.1