The patch titled
Subject: mm: remove VM_FAULT_WRITE
has been added to the -mm mm-unstable branch. Its filename is
mm-remove-vm_fault_write.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-remove-vm_fault_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: David Hildenbrand <david@xxxxxxxxxx>
Subject: mm: remove VM_FAULT_WRITE
Date: Fri, 30 Sep 2022 16:19:27 +0200
All users -- GUP and KSM -- are gone, let's just remove it.
Link: https://lkml.kernel.org/r/20220930141931.174362-4-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm_types.h | 3 ---
mm/huge_memory.c | 2 +-
mm/memory.c | 9 ++++-----
3 files changed, 5 insertions(+), 9 deletions(-)
--- a/include/linux/mm_types.h~mm-remove-vm_fault_write
+++ a/include/linux/mm_types.h
@@ -861,7 +861,6 @@ typedef __bitwise unsigned int vm_fault_
* @VM_FAULT_OOM: Out Of Memory
* @VM_FAULT_SIGBUS: Bad access
* @VM_FAULT_MAJOR: Page read from storage
- * @VM_FAULT_WRITE: Special case for get_user_pages
* @VM_FAULT_HWPOISON: Hit poisoned small page
* @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded
* in upper bits
@@ -882,7 +881,6 @@ enum vm_fault_reason {
VM_FAULT_OOM = (__force vm_fault_t)0x000001,
VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002,
VM_FAULT_MAJOR = (__force vm_fault_t)0x000004,
- VM_FAULT_WRITE = (__force vm_fault_t)0x000008,
VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010,
VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020,
VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040,
@@ -908,7 +906,6 @@ enum vm_fault_reason {
{ (__force unsigned int) VM_FAULT_OOM, "OOM" }, \
{ (__force unsigned int) VM_FAULT_SIGBUS, "SIGBUS" }, \
{ (__force unsigned int) VM_FAULT_MAJOR, "MAJOR" }, \
- { (__force unsigned int) VM_FAULT_WRITE, "WRITE" }, \
{ (__force unsigned int) VM_FAULT_HWPOISON, "HWPOISON" }, \
{ (__force unsigned int) VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \
{ (__force unsigned int) VM_FAULT_SIGSEGV, "SIGSEGV" }, \
--- a/mm/huge_memory.c~mm-remove-vm_fault_write
+++ a/mm/huge_memory.c
@@ -1333,7 +1333,7 @@ reuse:
if (pmdp_set_access_flags(vma, haddr, vmf->pmd, entry, 1))
update_mmu_cache_pmd(vma, vmf->address, vmf->pmd);
spin_unlock(vmf->ptl);
- return VM_FAULT_WRITE;
+ return 0;
}
unlock_fallback:
--- a/mm/memory.c~mm-remove-vm_fault_write
+++ a/mm/memory.c
@@ -3242,7 +3242,7 @@ static vm_fault_t wp_page_copy(struct vm
}
delayacct_wpcopy_end();
- return (page_copied && !unshare) ? VM_FAULT_WRITE : 0;
+ return 0;
oom_free_new:
put_page(new_page);
oom:
@@ -3306,14 +3306,14 @@ static vm_fault_t wp_pfn_shared(struct v
return finish_mkwrite_fault(vmf);
}
wp_page_reuse(vmf);
- return VM_FAULT_WRITE;
+ return 0;
}
static vm_fault_t wp_page_shared(struct vm_fault *vmf)
__releases(vmf->ptl)
{
struct vm_area_struct *vma = vmf->vma;
- vm_fault_t ret = VM_FAULT_WRITE;
+ vm_fault_t ret = 0;
get_page(vmf->page);
@@ -3464,7 +3464,7 @@ reuse:
return 0;
}
wp_page_reuse(vmf);
- return VM_FAULT_WRITE;
+ return 0;
} else if (unshare) {
/* No anonymous page -> nothing to do. */
pte_unmap_unlock(vmf->pte, vmf->ptl);
@@ -3983,7 +3983,6 @@ vm_fault_t do_swap_page(struct vm_fault
if (vmf->flags & FAULT_FLAG_WRITE) {
pte = maybe_mkwrite(pte_mkdirty(pte), vma);
vmf->flags &= ~FAULT_FLAG_WRITE;
- ret |= VM_FAULT_WRITE;
}
rmap_flags |= RMAP_EXCLUSIVE;
}
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
selftests-vm-add-test-to-measure-madv_unmergeable-performance.patch
mm-ksm-simplify-break_ksm-to-not-rely-on-vm_fault_write.patch
mm-remove-vm_fault_write.patch
mm-ksm-fix-ksm-cow-breaking-with-userfaultfd-wp-via-fault_flag_unshare.patch
mm-pagewalk-add-walk_page_range_vma.patch
mm-ksm-convert-break_ksm-to-use-walk_page_range_vma.patch
mm-gup-remove-foll_migration.patch
