[PATCH net-next v7 10/15] mm: page_frag: use __alloc_pages() to replace alloc_pages_node()

From: Yunsheng Lin
Date: Fri Jun 07 2024 - 08:46:03 EST


There are more new APIs calling __page_frag_cache_refill() in
this patchset, which may cause compiler not being able to inline
__page_frag_cache_refill() into __page_frag_alloc_va_align().

Not being able to do the inlining seems to casue some notiable
performance degradation in arm64 system with 64K PAGE_SIZE after
adding new API calling __page_frag_cache_refill().

It seems there is about 24Bytes binary size increase for
__page_frag_cache_refill() and __page_frag_cache_refill() in
arm64 system with 64K PAGE_SIZE. By doing the gdb disassembling,
It seems we can have more than 100Bytes decrease for the binary
size by using __alloc_pages() to replace alloc_pages_node(), as
there seems to be some unnecessary checking for nid being
NUMA_NO_NODE, especially when page_frag is still part of the mm
system.

CC: Alexander Duyck <alexander.duyck@xxxxxxxxx>
Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
---
mm/page_frag_cache.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/page_frag_cache.c b/mm/page_frag_cache.c
index b5ad6e9d316d..525b577b03a9 100644
--- a/mm/page_frag_cache.c
+++ b/mm/page_frag_cache.c
@@ -65,11 +65,11 @@ static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,

gfp_mask = (gfp_mask & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP |
__GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC;
- page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
- PAGE_FRAG_CACHE_MAX_ORDER);
+ page = __alloc_pages(gfp_mask, PAGE_FRAG_CACHE_MAX_ORDER,
+ numa_mem_id(), NULL);
#endif
if (unlikely(!page)) {
- page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
+ page = __alloc_pages(gfp, 0, numa_mem_id(), NULL);
if (unlikely(!page)) {
memset(nc, 0, sizeof(*nc));
return NULL;
--
2.33.0