The patch titled
Subject: mm: uninline the main body of vma_start_write()
has been added to the -mm mm-unstable branch. Its filename is
mm-uninline-the-main-body-of-vma_start_write.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-uninline-the-main-body-of-vma_start_write.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: mm: uninline the main body of vma_start_write()
Date: Thu, 26 Dec 2024 09:07:02 -0800
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/20241226170710.1159679-11-surenb@xxxxxxxxxx
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Hillf Danton <hdanton@xxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: kernel test robot <oliver.sang@xxxxxxxxx>
Cc: Klara Modin <klarasmodin@xxxxxxxxx>
Cc: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Lokesh Gidra <lokeshgidra@xxxxxxxxxx>
Cc: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Cc: Mateusz Guzik <mjguzik@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Cc: Sourav Panda <souravpanda@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 12 +++---------
mm/memory.c | 14 ++++++++++++++
2 files changed, 17 insertions(+), 9 deletions(-)
--- a/include/linux/mm.h~mm-uninline-the-main-body-of-vma_start_write
+++ a/include/linux/mm.h
@@ -787,6 +787,8 @@ static bool __is_vma_write_locked(struct
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
@@ -799,15 +801,7 @@ static inline void vma_start_write(struc
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)
--- a/mm/memory.c~mm-uninline-the-main-body-of-vma_start_write
+++ a/mm/memory.c
@@ -6328,6 +6328,20 @@ 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
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
seqlock-add-raw_seqcount_try_begin.patch
mm-convert-mm_lock_seq-to-a-proper-seqcount.patch
mm-introduce-mmap_lock_speculate_try_beginretry.patch
mm-introduce-vma_start_read_locked_nested-helpers.patch
mm-move-per-vma-lock-into-vm_area_struct.patch
mm-mark-vma-as-detached-until-its-added-into-vma-tree.patch
mm-modify-vma_iter_store_gfp-to-indicate-if-its-storing-a-new-vma.patch
mm-mark-vmas-detached-upon-exit.patch
mm-nommu-fix-the-last-places-where-vma-is-not-locked-before-being-attached.patch
types-move-struct-rcuwait-into-typesh.patch
mm-allow-vma_start_read_locked-vma_start_read_locked_nested-to-fail.patch
mm-move-mmap_init_lock-out-of-the-header-file.patch
mm-uninline-the-main-body-of-vma_start_write.patch
refcount-introduce-__refcount_addinc_not_zero_limited.patch
mm-replace-vm_lock-and-detached-flag-with-a-reference-count.patch
mm-debug-print-vm_refcnt-state-when-dumping-the-vma.patch
mm-debug-print-vm_refcnt-state-when-dumping-the-vma-fix.patch
mm-remove-extra-vma_numab_state_init-call.patch
mm-prepare-lock_vma_under_rcu-for-vma-reuse-possibility.patch
mm-make-vma-cache-slab_typesafe_by_rcu.patch
docs-mm-document-latest-changes-to-vm_lock.patch
