Vmalloc may offen get pages by loop invoke alloc_pags, this is
cost too much time in count watermark/cpuset or something.
Let's just try alloc by alloc_pages_bulk, if failed, fullback in
original path.
With my own test, simulate loop alloc_page and alloc_pages_bulk_array,
get this:
size 1M 10M 20M 30
normal 44 1278 3665 5581
test 34 889 2167 3300
optimize 22% 30% 40% 40%
And in my vmalloc top sort, zram/f2fs may alloc more than 20MB, so,
It's worth to use alloc_pages_bulk.
Signed-off-by: Yang Huan <link@xxxxxxxx>
---
mm/vmalloc.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index a13ac524f6ff..b5af7b4e30bc 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2791,17 +2791,23 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
}
area->pages = pages;
- area->nr_pages = nr_small_pages;
+ area->nr_pages = 0;
set_vm_area_page_order(area, page_shift - PAGE_SHIFT);
page_order = vm_area_page_order(area);
-
+ /* first try alloc in alloc bulk when order is 0*/
+ if (!page_order) {
+ area->nr_pages = alloc_pages_bulk_array(
+ gfp_mask, nr_small_pages, area->pages);
+ if (likely(area->nr_pages == nr_small_pages))
+ goto success;
+ }
/*
* Careful, we allocate and map page_order pages, but tracking is done
* per PAGE_SIZE page so as to keep the vm_struct APIs independent of
* the physical/mapped size.
*/
- for (i = 0; i < area->nr_pages; i += 1U << page_order) {
+ for (i = area->nr_pages; i < nr_small_pages; i += 1U << page_order) {
struct page *page;
int p;
@@ -2824,6 +2830,8 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
if (gfpflags_allow_blocking(gfp_mask))
cond_resched();
}
+ area->nr_pages = nr_small_pages;
+success:
atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
if (vmap_pages_range(addr, addr + size, prot, pages, page_shift) < 0) {
--
2.32.0
