From c2e65ebc02fb60b64a1c5689fe2c6f60d0fc1626 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@redhat.com>
Date: Tue, 9 Apr 2024 21:22:45 +0200
Subject: [PATCH] mm/rmap: always inline anon/file rmap duplication of a single
PTE
As we grow the code, the compiler might make stupid decisions and
unnecessarily degrade fork() performance. Let's make sure to always
inline functions that operate on a single PTE so the compiler will always
optimize out the loop and avoid a function call.
This is a preparation for maintining a total mapcount for large folios.
Link: https://lkml.kernel.org/r/20240409192301.907377-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/rmap.h | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 9bf9324214fc3..9549d78928bb1 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -347,8 +347,12 @@ static inline void folio_dup_file_rmap_ptes(struct folio *folio,
{
__folio_dup_file_rmap(folio, page, nr_pages, RMAP_LEVEL_PTE);
}
-#define folio_dup_file_rmap_pte(folio, page) \
- folio_dup_file_rmap_ptes(folio, page, 1)
+
+static __always_inline void folio_dup_file_rmap_pte(struct folio *folio,
+ struct page *page)
+{
+ __folio_dup_file_rmap(folio, page, 1, RMAP_LEVEL_PTE);
+}
/**
* folio_dup_file_rmap_pmd - duplicate a PMD mapping of a page range of a folio
@@ -448,8 +452,13 @@ static inline int folio_try_dup_anon_rmap_ptes(struct folio *folio,
return __folio_try_dup_anon_rmap(folio, page, nr_pages, src_vma,
RMAP_LEVEL_PTE);
}
-#define folio_try_dup_anon_rmap_pte(folio, page, vma) \
- folio_try_dup_anon_rmap_ptes(folio, page, 1, vma)
+
+static __always_inline int folio_try_dup_anon_rmap_pte(struct folio *folio,
+ struct page *page, struct vm_area_struct *src_vma)
+{
+ return __folio_try_dup_anon_rmap(folio, page, 1, src_vma,
+ RMAP_LEVEL_PTE);
+}
/**
* folio_try_dup_anon_rmap_pmd - try duplicating a PMD mapping of a page range
--
2.30.2