The quilt patch titled
Subject: mm: optimise vmf_anon_prepare() for VMAs without an anon_vma
has been removed from the -mm tree. Its filename was
mm-optimise-vmf_anon_prepare-for-vmas-without-an-anon_vma.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm: optimise vmf_anon_prepare() for VMAs without an anon_vma
Date: Fri, 26 Apr 2024 15:45:03 +0100
If the mmap_lock can be taken for read, we can call __anon_vma_prepare()
while holding it, saving ourselves a trip back through the fault handler.
Link: https://lkml.kernel.org/r/20240426144506.1290619-5-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Jann Horn <jannh@xxxxxxxxxx>
Reviewed-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
--- a/mm/memory.c~mm-optimise-vmf_anon_prepare-for-vmas-without-an-anon_vma
+++ a/mm/memory.c
@@ -3232,16 +3232,21 @@ static inline vm_fault_t vmf_can_call_fa
vm_fault_t vmf_anon_prepare(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
+ vm_fault_t ret = 0;
if (likely(vma->anon_vma))
return 0;
if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
- vma_end_read(vma);
- return VM_FAULT_RETRY;
+ if (!mmap_read_trylock(vma->vm_mm)) {
+ vma_end_read(vma);
+ return VM_FAULT_RETRY;
+ }
}
if (__anon_vma_prepare(vma))
- return VM_FAULT_OOM;
- return 0;
+ ret = VM_FAULT_OOM;
+ if (vmf->flags & FAULT_FLAG_VMA_LOCK)
+ mmap_read_unlock(vma->vm_mm);
+ return ret;
}
/*
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
squashfs-convert-squashfs_symlink_read_folio-to-use-folio-apis.patch
squashfs-remove-calls-to-set-the-folio-error-flag.patch
nilfs2-remove-calls-to-folio_set_error-and-folio_clear_error.patch
