From ef0258857d40dd8e33c52e28ea3a1c82099a6879 Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Tue, 21 Oct 2025 21:21:39 +0000 Subject: [PATCH] mm/huge_memory: avoid reinvoking folio_test_anon() Patch series "mm/huge_memory: cleanup __split_unmapped_folio()", v3. This patch series cleans up and optimizes the internal logic of the __split_unmapped_folio() function. The goal is to improve clarity and efficiency by eliminating redundant checks, caching stable attribute values, and simplifying the iteration logic used for updating folio statistics. These changes make the code easier to follow and maintain. The split_huge_page_test selftest pass. This patch (of 4): During the execution of __split_unmapped_folio(), the folio's anon/!anon attribute is invariant (not expected to change). Therefore, it is safe and more efficient to retrieve this attribute once at the start and reuse it throughout the function. Link: https://lkml.kernel.org/r/20251021212142.25766-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20251016004613.514-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20251016004613.514-2-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20251021212142.25766-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang Reviewed-by: Zi Yan Reviewed-by: wang lian Reviewed-by: Barry Song Acked-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Baolin Wang Cc: Dev Jain Cc: Lance Yang Cc: Liam Howlett Cc: Mariano Pache Cc: Ryan Roberts Cc: Nico Pache Signed-off-by: Andrew Morton --- mm/huge_memory.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index ffdf2ccf82691..5d95e3462c433 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3401,6 +3401,7 @@ static int __split_unmapped_folio(struct folio *folio, int new_order, struct page *split_at, struct xa_state *xas, struct address_space *mapping, bool uniform_split) { + const bool is_anon = folio_test_anon(folio); int order = folio_order(folio); int start_order = uniform_split ? new_order : order - 1; bool stop_split = false; @@ -3408,7 +3409,7 @@ static int __split_unmapped_folio(struct folio *folio, int new_order, int split_order; int ret = 0; - if (folio_test_anon(folio)) + if (is_anon) mod_mthp_stat(order, MTHP_STAT_NR_ANON, -1); /* @@ -3423,7 +3424,7 @@ static int __split_unmapped_folio(struct folio *folio, int new_order, struct folio *new_folio; /* order-1 anonymous folio is not supported */ - if (folio_test_anon(folio) && split_order == 1) + if (is_anon && split_order == 1) continue; if (uniform_split && split_order != new_order) continue; @@ -3475,7 +3476,7 @@ static int __split_unmapped_folio(struct folio *folio, int new_order, if (split_order != new_order && !stop_split) continue; } - if (folio_test_anon(new_folio)) + if (is_anon) mod_mthp_stat(folio_order(new_folio), MTHP_STAT_NR_ANON, 1); } -- 2.47.3