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mm/nommu: use alloc_pages_exact() rather than its own implementation

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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 <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joonsoo Kim 2014-12-12 16:55:55 -08:00 committed by Linus Torvalds
parent 031bc5743f
commit dbc8358c72
1 changed files with 11 additions and 22 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

33
mm/nommu.c
View file

@ -1149,8 +1149,7 @@ static int do_mmap_private(struct vm_area_struct *vma,
unsigned long len, unsigned long len,
unsigned long capabilities) unsigned long capabilities)
{ {
struct page *pages; unsigned long total, point;
unsigned long total, point, n;
void *base; void *base;
int ret, order; int ret, order;
@ -1182,33 +1181,23 @@ static int do_mmap_private(struct vm_area_struct *vma,
order = get_order(len); order = get_order(len);
kdebug("alloc order %d for %lx", order, len); kdebug("alloc order %d for %lx", order, len);
pages = alloc_pages(GFP_KERNEL, order);
if (!pages)
goto enomem;
total = 1 << order; total = 1 << order;
atomic_long_add(total, &mmap_pages_allocated);
point = len >> PAGE_SHIFT; point = len >> PAGE_SHIFT;
/* we allocated a power-of-2 sized page set, so we may want to trim off /* we don't want to allocate a power-of-2 sized page set */
* the excess */
if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) { if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) {
while (total > point) { total = point;
order = ilog2(total - point); kdebug("try to alloc exact %lu pages", total);
n = 1 << order; base = alloc_pages_exact(len, GFP_KERNEL);
kdebug("shave %lu/%lu @%lu", n, total - point, total); } else {
atomic_long_sub(n, &mmap_pages_allocated); base = (void *)__get_free_pages(GFP_KERNEL, order);
total -= n;
set_page_refcounted(pages + total);
__free_pages(pages + total, order);
}
} }
for (point = 1; point < total; point++) if (!base)
set_page_refcounted(&pages[point]); goto enomem;
atomic_long_add(total, &mmap_pages_allocated);
base = page_address(pages);
region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY;
region->vm_start = (unsigned long) base; region->vm_start = (unsigned long) base;
region->vm_end = region->vm_start + len; region->vm_end = region->vm_start + len;