2024-04-15 13:44:25

by Yunsheng Lin

[permalink] [raw]
Subject: [PATCH net-next v2 03/15] mm: page_frag: use free_unref_page() to free page fragment

free_the_page() used by page_frag call free_unref_page() or
__free_pages_ok() depending on pcp_allowed_order(), as the
max order of page allocated for page_frag is 3, the checking
in pcp_allowed_order() is unnecessary.

So call free_unref_page() directly to free a page_frag page
to aovid the unnecessary checking.

As the free_the_page() is a static function in page_alloc.c,
using the new one also allow moving page_frag related code
to a new file in the next patch.

Signed-off-by: Yunsheng Lin <[email protected]>
---
mm/page_alloc.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 14d39f34d336..7adb29f8f364 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4693,6 +4693,9 @@ static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
gfp_t gfp = gfp_mask;

#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
+ /* Ensure free_unref_page() can be used to free the page fragment */
+ BUILD_BUG_ON(PAGE_FRAG_CACHE_MAX_ORDER > PAGE_ALLOC_COSTLY_ORDER);
+
gfp_mask = (gfp_mask & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP |
__GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC;
page = alloc_pages_node(NUMA_NO_NODE, gfp_mask,
@@ -4722,7 +4725,7 @@ void __page_frag_cache_drain(struct page *page, unsigned int count)
VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);

if (page_ref_sub_and_test(page, count))
- free_the_page(page, compound_order(page));
+ free_unref_page(page, compound_order(page));
}
EXPORT_SYMBOL(__page_frag_cache_drain);

@@ -4763,7 +4766,7 @@ void *__page_frag_alloc_align(struct page_frag_cache *nc,
goto refill;

if (unlikely(nc->pfmemalloc)) {
- free_the_page(page, compound_order(page));
+ free_unref_page(page, compound_order(page));
goto refill;
}

@@ -4807,7 +4810,7 @@ void page_frag_free(void *addr)
struct page *page = virt_to_head_page(addr);

if (unlikely(put_page_testzero(page)))
- free_the_page(page, compound_order(page));
+ free_unref_page(page, compound_order(page));
}
EXPORT_SYMBOL(page_frag_free);

--
2.33.0