From 8bb60ef928b2383666f4716205341587b1412bbc Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Thu, 13 Feb 2025 14:46:46 -0800 Subject: [PATCH] FROMGIT: mm: uninline the main body of vma_start_write() vma_start_write() is used in many places and will grow in size very soon. It is not used in performance critical paths and uninlining it should limit the future code size growth. No functional changes. Link: https://lkml.kernel.org/r/20250213224655.1680278-10-surenb@google.com Signed-off-by: Suren Baghdasaryan Reviewed-by: Vlastimil Babka Reviewed-by: Lorenzo Stoakes Tested-by: Shivank Garg Link: https://lkml.kernel.org/r/5e19ec93-8307-47c2-bb13-3ddf7150624e@amd.com Cc: Christian Brauner Cc: David Hildenbrand Cc: David Howells Cc: Davidlohr Bueso Cc: Hillf Danton Cc: Hugh Dickins Cc: Jann Horn Cc: Johannes Weiner Cc: Jonathan Corbet Cc: Klara Modin Cc: Liam R. Howlett Cc: Lokesh Gidra Cc: Mateusz Guzik Cc: Matthew Wilcox Cc: Mel Gorman Cc: Michal Hocko Cc: Minchan Kim Cc: Oleg Nesterov Cc: Pasha Tatashin Cc: "Paul E . McKenney" Cc: Peter Xu Cc: Peter Zijlstra (Intel) Cc: Shakeel Butt Cc: Sourav Panda Cc: Wei Yang Cc: Will Deacon Signed-off-by: Andrew Morton (cherry picked from commit b18eb04cebae1b22ea6380c64c2ba65216e1e8b6 https: //git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-unstable) Bug: 322132947 Change-Id: I5ed47a39202909ecf5c7602835b46821ed88c08b Signed-off-by: Suren Baghdasaryan --- include/linux/mm.h | 12 +++--------- mm/memory.c | 14 ++++++++++++++ 2 files changed, 17 insertions(+), 9 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 437b7787aa96..4f015297b765 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -774,6 +774,8 @@ static bool __is_vma_write_locked(struct vm_area_struct *vma, unsigned int *mm_l return (vma->vm_lock_seq == *mm_lock_seq); } +void __vma_start_write(struct vm_area_struct *vma, unsigned int mm_lock_seq); + /* * Begin writing to a VMA. * Exclude concurrent readers under the per-VMA lock until the currently @@ -786,15 +788,7 @@ static inline void vma_start_write(struct vm_area_struct *vma) if (__is_vma_write_locked(vma, &mm_lock_seq)) return; - down_write(&vma->vm_lock.lock); - /* - * We should use WRITE_ONCE() here because we can have concurrent reads - * from the early lockless pessimistic check in vma_start_read(). - * We don't really care about the correctness of that early check, but - * we should use WRITE_ONCE() for cleanliness and to keep KCSAN happy. - */ - WRITE_ONCE(vma->vm_lock_seq, mm_lock_seq); - up_write(&vma->vm_lock.lock); + __vma_start_write(vma, mm_lock_seq); } static inline void vma_assert_write_locked(struct vm_area_struct *vma) diff --git a/mm/memory.c b/mm/memory.c index a1497dd498f7..e753e8ac0ac8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -6234,6 +6234,20 @@ fail: #endif #ifdef CONFIG_PER_VMA_LOCK +void __vma_start_write(struct vm_area_struct *vma, unsigned int mm_lock_seq) +{ + down_write(&vma->vm_lock.lock); + /* + * We should use WRITE_ONCE() here because we can have concurrent reads + * from the early lockless pessimistic check in vma_start_read(). + * We don't really care about the correctness of that early check, but + * we should use WRITE_ONCE() for cleanliness and to keep KCSAN happy. + */ + WRITE_ONCE(vma->vm_lock_seq, mm_lock_seq); + up_write(&vma->vm_lock.lock); +} +EXPORT_SYMBOL_GPL(__vma_start_write); + /* * Lookup and lock a VMA under RCU protection. Returned VMA is guaranteed to be * stable and not isolated. If the VMA is not found or is being modified the