* [PATCH v2 0/3] mm/memory: remove unused vmf_insert_mixed_mkwrite()
@ 2026-10-02 16:05 Sang-Heon Jeon
2026-10-02 16:05 ` [PATCH v2 1/3] " Sang-Heon Jeon
` (2 more replies)
0 siblings, 3 replies; 13+ messages in thread
From: Sang-Heon Jeon @ 2026-10-02 16:05 UTC (permalink / raw)
To: Andrew Morton, David Hildenbrand
Cc: Anshuman Khandual, Jose A . Perez de Azpillaga, Liam R. Howlett,
linux-kernel, linux-mm, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka
Hello,
Since commit 38607c62b34b ("fs/dax: properly refcount fs dax pages"),
vmf_insert_mixed_mkwrite() has no callers. This series removes it and
the mkwrite handling that only it used.
Patch 1 removes the function.
Patch 2 removes the mkwrite argument, which is then always false. It
also removes the unreachable code in insert_pfn().
Patch 3 merges __vm_insert_mixed() into vmf_insert_mixed().
No functional change.
---
Changes from v1 [1]
- Split into three patches for easier review
- Move the comment about -EBUSY handling above the check in
__vm_insert_mixed()
[1] https://lore.kernel.org/all/20260929143707.450805-1-ekffu200098@gmail.com/
---
Sang-Heon Jeon (3):
mm/memory: remove unused vmf_insert_mixed_mkwrite()
mm/memory: remove the mkwrite argument from __vm_insert_mixed()
mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed()
include/linux/mm.h | 2 --
mm/memory.c | 81 ++++++++++++++--------------------------------
2 files changed, 24 insertions(+), 59 deletions(-)
base-commit: 1c2b8d2725f84b43fabe3b3e9628c91db8ca6c65
--
2.43.0
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v2 1/3] mm/memory: remove unused vmf_insert_mixed_mkwrite()
2026-10-02 16:05 [PATCH v2 0/3] mm/memory: remove unused vmf_insert_mixed_mkwrite() Sang-Heon Jeon
@ 2026-10-02 16:05 ` Sang-Heon Jeon
2026-10-02 18:35 ` SJ Park
` (2 more replies)
2026-10-02 16:05 ` [PATCH v2 2/3] mm/memory: remove the mkwrite argument from __vm_insert_mixed() Sang-Heon Jeon
2026-10-02 16:05 ` [PATCH v2 3/3] mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed() Sang-Heon Jeon
2 siblings, 3 replies; 13+ messages in thread
From: Sang-Heon Jeon @ 2026-10-02 16:05 UTC (permalink / raw)
To: Andrew Morton, David Hildenbrand
Cc: Anshuman Khandual, Jose A . Perez de Azpillaga, Liam R. Howlett,
linux-kernel, linux-mm, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka
Since commit 38607c62b34b ("fs/dax: properly refcount fs dax pages"),
vmf_insert_mixed_mkwrite() has no callers.
So remove the function and its declaration.
The comment above the function describes the -EBUSY handling in
__vm_insert_mixed(). Move it above that check.
No functional change.
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
include/linux/mm.h | 2 --
mm/memory.c | 16 +++++-----------
2 files changed, 5 insertions(+), 13 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index c038d06825c3..2ac734efd4ec 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -5008,8 +5008,6 @@ vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn, pgprot_t pgprot);
vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn);
-vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
- unsigned long addr, unsigned long pfn);
int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
static inline vm_fault_t vmf_insert_page(struct vm_area_struct *vma,
diff --git a/mm/memory.c b/mm/memory.c
index 330cde31bf8b..4b2e4be28031 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3052,6 +3052,11 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
if (err == -ENOMEM)
return VM_FAULT_OOM;
+ /*
+ * If the insertion of PTE failed because someone else already added a
+ * different entry in the mean time, we treat that as success as we assume
+ * the same entry was actually inserted.
+ */
if (err < 0 && err != -EBUSY)
return VM_FAULT_SIGBUS;
@@ -3085,17 +3090,6 @@ vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
}
EXPORT_SYMBOL(vmf_insert_mixed);
-/*
- * If the insertion of PTE failed because someone else already added a
- * different entry in the mean time, we treat that as success as we assume
- * the same entry was actually inserted.
- */
-vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
- unsigned long addr, unsigned long pfn)
-{
- return __vm_insert_mixed(vma, addr, pfn, true);
-}
-
/*
* maps a range of physical memory into the requested pages. the old
* mappings are removed. any references to nonexistent pages results
--
2.43.0
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v2 2/3] mm/memory: remove the mkwrite argument from __vm_insert_mixed()
2026-10-02 16:05 [PATCH v2 0/3] mm/memory: remove unused vmf_insert_mixed_mkwrite() Sang-Heon Jeon
2026-10-02 16:05 ` [PATCH v2 1/3] " Sang-Heon Jeon
@ 2026-10-02 16:05 ` Sang-Heon Jeon
2026-10-02 18:45 ` SJ Park
` (2 more replies)
2026-10-02 16:05 ` [PATCH v2 3/3] mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed() Sang-Heon Jeon
2 siblings, 3 replies; 13+ messages in thread
From: Sang-Heon Jeon @ 2026-10-02 16:05 UTC (permalink / raw)
To: Andrew Morton, David Hildenbrand
Cc: Anshuman Khandual, Jose A . Perez de Azpillaga, Liam R. Howlett,
linux-kernel, linux-mm, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka
__vm_insert_mixed() is only called from vmf_insert_mixed() with
mkwrite == false, so mkwrite is also always false in vm_mixed_ok()
and insert_pfn().
So remove the argument and the unreachable code in insert_pfn().
No functional change.
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
mm/memory.c | 57 +++++++++++++++++------------------------------------
1 file changed, 18 insertions(+), 39 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 4b2e4be28031..6c1d38eba7b2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2453,7 +2453,14 @@ static int insert_page_into_pte_locked(struct vm_area_struct *vma, pte_t *pte,
if (!mkwrite)
return -EBUSY;
- /* see insert_pfn(). */
+ /*
+ * For read faults on private mappings the PFN passed in may
+ * not match the PFN we have mapped if the mapped PFN is a
+ * writeable COW page. In the mkwrite case we are creating a
+ * writable PTE for a shared mapping and we expect the PFNs to
+ * match. If they don't match, we are likely racing with block
+ * allocation and mapping invalidation.
+ */
if (pte_pfn(pteval) != page_to_pfn(page)) {
WARN_ON_ONCE(!is_zero_pfn(pte_pfn(pteval)));
return -EFAULT;
@@ -2858,7 +2865,7 @@ int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages,
EXPORT_SYMBOL(vm_map_pages_zero);
static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr,
- unsigned long pfn, pgprot_t prot, bool mkwrite)
+ unsigned long pfn, pgprot_t prot)
{
struct mm_struct *mm = vma->vm_mm;
pte_t *pte, entry;
@@ -2868,38 +2875,12 @@ static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr,
if (!pte)
return VM_FAULT_OOM;
entry = ptep_get(pte);
- if (!pte_none(entry)) {
- if (mkwrite) {
- /*
- * For read faults on private mappings the PFN passed
- * in may not match the PFN we have mapped if the
- * mapped PFN is a writeable COW page. In the mkwrite
- * case we are creating a writable PTE for a shared
- * mapping and we expect the PFNs to match. If they
- * don't match, we are likely racing with block
- * allocation and mapping invalidation so just skip the
- * update.
- */
- if (pte_pfn(entry) != pfn) {
- WARN_ON_ONCE(!is_zero_pfn(pte_pfn(entry)));
- goto out_unlock;
- }
- entry = pte_mkyoung(entry);
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- if (ptep_set_access_flags(vma, addr, pte, entry, 1))
- update_mmu_cache(vma, addr, pte);
- }
+ if (!pte_none(entry))
goto out_unlock;
- }
/* Ok, finally just insert the thing.. */
entry = pte_mkspecial(pfn_pte(pfn, prot));
- if (mkwrite) {
- entry = pte_mkyoung(entry);
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- }
-
set_pte_at(mm, addr, pte, entry);
update_mmu_cache(vma, addr, pte); /* XXX: why not for insert_page? */
@@ -2967,7 +2948,7 @@ vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
pfnmap_setup_cachemode_pfn(pfn, &pgprot);
- return insert_pfn(vma, addr, pfn, pgprot, false);
+ return insert_pfn(vma, addr, pfn, pgprot);
}
EXPORT_SYMBOL(vmf_insert_pfn_prot);
@@ -2998,11 +2979,9 @@ vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
}
EXPORT_SYMBOL(vmf_insert_pfn);
-static bool vm_mixed_ok(struct vm_area_struct *vma, unsigned long pfn,
- bool mkwrite)
+static bool vm_mixed_ok(struct vm_area_struct *vma, unsigned long pfn)
{
- if (unlikely(is_zero_pfn(pfn)) &&
- (mkwrite || !vm_mixed_zeropage_allowed(vma)))
+ if (unlikely(is_zero_pfn(pfn)) && !vm_mixed_zeropage_allowed(vma))
return false;
/* these checks mirror the abort conditions in vm_normal_page */
if (vma->vm_flags & VM_MIXEDMAP)
@@ -3013,12 +2992,12 @@ static bool vm_mixed_ok(struct vm_area_struct *vma, unsigned long pfn,
}
static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
- unsigned long addr, unsigned long pfn, bool mkwrite)
+ unsigned long addr, unsigned long pfn)
{
pgprot_t pgprot = vma->vm_page_prot;
int err;
- if (!vm_mixed_ok(vma, pfn, mkwrite))
+ if (!vm_mixed_ok(vma, pfn))
return VM_FAULT_SIGBUS;
if (addr < vma->vm_start || addr >= vma->vm_end)
@@ -3045,9 +3024,9 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
* result in pfn_t_has_page() == false.
*/
page = pfn_to_page(pfn);
- err = insert_page(vma, addr, page, pgprot, mkwrite);
+ err = insert_page(vma, addr, page, pgprot, false);
} else {
- return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
+ return insert_pfn(vma, addr, pfn, pgprot);
}
if (err == -ENOMEM)
@@ -3086,7 +3065,7 @@ EXPORT_SYMBOL_GPL(vmf_insert_page_mkwrite);
vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn)
{
- return __vm_insert_mixed(vma, addr, pfn, false);
+ return __vm_insert_mixed(vma, addr, pfn);
}
EXPORT_SYMBOL(vmf_insert_mixed);
--
2.43.0
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v2 3/3] mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed()
2026-10-02 16:05 [PATCH v2 0/3] mm/memory: remove unused vmf_insert_mixed_mkwrite() Sang-Heon Jeon
2026-10-02 16:05 ` [PATCH v2 1/3] " Sang-Heon Jeon
2026-10-02 16:05 ` [PATCH v2 2/3] mm/memory: remove the mkwrite argument from __vm_insert_mixed() Sang-Heon Jeon
@ 2026-10-02 16:05 ` Sang-Heon Jeon
2026-10-02 18:47 ` SJ Park
` (2 more replies)
2 siblings, 3 replies; 13+ messages in thread
From: Sang-Heon Jeon @ 2026-10-02 16:05 UTC (permalink / raw)
To: Andrew Morton, David Hildenbrand
Cc: Anshuman Khandual, Jose A . Perez de Azpillaga, Liam R. Howlett,
linux-kernel, linux-mm, Lorenzo Stoakes, Michal Hocko,
Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka
vmf_insert_mixed() just calls __vm_insert_mixed() with the same
arguments.
So merge __vm_insert_mixed() into vmf_insert_mixed().
No functional change.
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
mm/memory.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 6c1d38eba7b2..bde650e207c9 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2991,8 +2991,8 @@ static bool vm_mixed_ok(struct vm_area_struct *vma, unsigned long pfn)
return false;
}
-static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
- unsigned long addr, unsigned long pfn)
+vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long pfn)
{
pgprot_t pgprot = vma->vm_page_prot;
int err;
@@ -3041,6 +3041,7 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
return VM_FAULT_NOPAGE;
}
+EXPORT_SYMBOL(vmf_insert_mixed);
vm_fault_t vmf_insert_page_mkwrite(struct vm_fault *vmf, struct page *page,
bool write)
@@ -3062,13 +3063,6 @@ vm_fault_t vmf_insert_page_mkwrite(struct vm_fault *vmf, struct page *page,
}
EXPORT_SYMBOL_GPL(vmf_insert_page_mkwrite);
-vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
- unsigned long pfn)
-{
- return __vm_insert_mixed(vma, addr, pfn);
-}
-EXPORT_SYMBOL(vmf_insert_mixed);
-
/*
* maps a range of physical memory into the requested pages. the old
* mappings are removed. any references to nonexistent pages results
--
2.43.0
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 1/3] mm/memory: remove unused vmf_insert_mixed_mkwrite()
2026-10-02 16:05 ` [PATCH v2 1/3] " Sang-Heon Jeon
@ 2026-10-02 18:35 ` SJ Park
2026-10-02 23:32 ` Jose A. Perez de Azpillaga
2026-10-05 2:36 ` Anshuman Khandual
2 siblings, 0 replies; 13+ messages in thread
From: SJ Park @ 2026-10-02 18:35 UTC (permalink / raw)
To: Sang-Heon Jeon
Cc: SJ Park, Andrew Morton, David Hildenbrand, Anshuman Khandual,
Jose A . Perez de Azpillaga, Liam R. Howlett, linux-kernel,
linux-mm, Lorenzo Stoakes, Michal Hocko, Mike Rapoport,
Suren Baghdasaryan, Vlastimil Babka
On Sat, 3 Oct 2026 01:05:32 +0900 Sang-Heon Jeon <ekffu200098@gmail.com> wrote:
> Since commit 38607c62b34b ("fs/dax: properly refcount fs dax pages"),
> vmf_insert_mixed_mkwrite() has no callers.
>
> So remove the function and its declaration.
>
> The comment above the function describes the -EBUSY handling in
> __vm_insert_mixed(). Move it above that check.
>
> No functional change.
Looks good to me.
>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Thanks,
SJ
[...]
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 2/3] mm/memory: remove the mkwrite argument from __vm_insert_mixed()
2026-10-02 16:05 ` [PATCH v2 2/3] mm/memory: remove the mkwrite argument from __vm_insert_mixed() Sang-Heon Jeon
@ 2026-10-02 18:45 ` SJ Park
2026-10-02 23:34 ` Jose A. Perez de Azpillaga
2026-10-05 2:40 ` Anshuman Khandual
2 siblings, 0 replies; 13+ messages in thread
From: SJ Park @ 2026-10-02 18:45 UTC (permalink / raw)
To: Sang-Heon Jeon
Cc: SJ Park, Andrew Morton, David Hildenbrand, Anshuman Khandual,
Jose A . Perez de Azpillaga, Liam R. Howlett, linux-kernel,
linux-mm, Lorenzo Stoakes, Michal Hocko, Mike Rapoport,
Suren Baghdasaryan, Vlastimil Babka
On Sat, 3 Oct 2026 01:05:33 +0900 Sang-Heon Jeon <ekffu200098@gmail.com> wrote:
> __vm_insert_mixed() is only called from vmf_insert_mixed() with
> mkwrite == false, so mkwrite is also always false in vm_mixed_ok()
> and insert_pfn().
>
> So remove the argument and the unreachable code in insert_pfn().
>
> No functional change.
Looks correct to me.
>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Thanks,
SJ
[...]
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 3/3] mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed()
2026-10-02 16:05 ` [PATCH v2 3/3] mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed() Sang-Heon Jeon
@ 2026-10-02 18:47 ` SJ Park
2026-10-02 23:35 ` Jose A. Perez de Azpillaga
2026-10-05 3:14 ` Anshuman Khandual
2 siblings, 0 replies; 13+ messages in thread
From: SJ Park @ 2026-10-02 18:47 UTC (permalink / raw)
To: Sang-Heon Jeon
Cc: SJ Park, Andrew Morton, David Hildenbrand, Anshuman Khandual,
Jose A . Perez de Azpillaga, Liam R. Howlett, linux-kernel,
linux-mm, Lorenzo Stoakes, Michal Hocko, Mike Rapoport,
Suren Baghdasaryan, Vlastimil Babka
On Sat, 3 Oct 2026 01:05:34 +0900 Sang-Heon Jeon <ekffu200098@gmail.com> wrote:
> vmf_insert_mixed() just calls __vm_insert_mixed() with the same
> arguments.
>
> So merge __vm_insert_mixed() into vmf_insert_mixed().
>
> No functional change.
Makes sense to me.
>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Thanks,
SJ
[...]
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 1/3] mm/memory: remove unused vmf_insert_mixed_mkwrite()
2026-10-02 16:05 ` [PATCH v2 1/3] " Sang-Heon Jeon
2026-10-02 18:35 ` SJ Park
@ 2026-10-02 23:32 ` Jose A. Perez de Azpillaga
2026-10-05 2:36 ` Anshuman Khandual
2 siblings, 0 replies; 13+ messages in thread
From: Jose A. Perez de Azpillaga @ 2026-10-02 23:32 UTC (permalink / raw)
To: Sang-Heon Jeon
Cc: Andrew Morton, David Hildenbrand, Anshuman Khandual,
Liam R. Howlett, linux-kernel, linux-mm, Lorenzo Stoakes,
Michal Hocko, Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka
On Sat, Oct 03, 2026 at 01:05:32AM +0900, Sang-Heon Jeon wrote:
> Since commit 38607c62b34b ("fs/dax: properly refcount fs dax pages"),
> vmf_insert_mixed_mkwrite() has no callers.
>
> So remove the function and its declaration.
>
> The comment above the function describes the -EBUSY handling in
> __vm_insert_mixed(). Move it above that check.
>
> No functional change.
>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
all three LGMT so I'll RB them :)
Reviewed-by: Jose A. Perez de Azpillaga <azpijr@gmail.com>
--
cheers,
jose a. p-a
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 2/3] mm/memory: remove the mkwrite argument from __vm_insert_mixed()
2026-10-02 16:05 ` [PATCH v2 2/3] mm/memory: remove the mkwrite argument from __vm_insert_mixed() Sang-Heon Jeon
2026-10-02 18:45 ` SJ Park
@ 2026-10-02 23:34 ` Jose A. Perez de Azpillaga
2026-10-05 2:40 ` Anshuman Khandual
2 siblings, 0 replies; 13+ messages in thread
From: Jose A. Perez de Azpillaga @ 2026-10-02 23:34 UTC (permalink / raw)
To: Sang-Heon Jeon
Cc: Andrew Morton, David Hildenbrand, Anshuman Khandual,
Liam R. Howlett, linux-kernel, linux-mm, Lorenzo Stoakes,
Michal Hocko, Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka
On Sat, Oct 03, 2026 at 01:05:33AM +0900, Sang-Heon Jeon wrote:
> __vm_insert_mixed() is only called from vmf_insert_mixed() with
> mkwrite == false, so mkwrite is also always false in vm_mixed_ok()
> and insert_pfn().
>
> So remove the argument and the unreachable code in insert_pfn().
>
> No functional change.
>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Reviewed-by: Jose A. Perez de Azpillaga <azpijr@gmail.com>
--
cheers,
jose a. p-a
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 3/3] mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed()
2026-10-02 16:05 ` [PATCH v2 3/3] mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed() Sang-Heon Jeon
2026-10-02 18:47 ` SJ Park
@ 2026-10-02 23:35 ` Jose A. Perez de Azpillaga
2026-10-05 3:14 ` Anshuman Khandual
2 siblings, 0 replies; 13+ messages in thread
From: Jose A. Perez de Azpillaga @ 2026-10-02 23:35 UTC (permalink / raw)
To: Sang-Heon Jeon
Cc: Andrew Morton, David Hildenbrand, Anshuman Khandual,
Liam R. Howlett, linux-kernel, linux-mm, Lorenzo Stoakes,
Michal Hocko, Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka
On Sat, Oct 03, 2026 at 01:05:34AM +0900, Sang-Heon Jeon wrote:
> vmf_insert_mixed() just calls __vm_insert_mixed() with the same
> arguments.
>
> So merge __vm_insert_mixed() into vmf_insert_mixed().
>
> No functional change.
>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Reviewed-by: Jose A. Perez de Azpillaga <azpijr@gmail.com>
--
cheers,
jose a. p-a
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 1/3] mm/memory: remove unused vmf_insert_mixed_mkwrite()
2026-10-02 16:05 ` [PATCH v2 1/3] " Sang-Heon Jeon
2026-10-02 18:35 ` SJ Park
2026-10-02 23:32 ` Jose A. Perez de Azpillaga
@ 2026-10-05 2:36 ` Anshuman Khandual
2 siblings, 0 replies; 13+ messages in thread
From: Anshuman Khandual @ 2026-10-05 2:36 UTC (permalink / raw)
To: Sang-Heon Jeon
Cc: Andrew Morton, David Hildenbrand, Jose A . Perez de Azpillaga,
Liam R. Howlett, linux-kernel, linux-mm, Lorenzo Stoakes,
Michal Hocko, Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka
On Sat, Oct 03, 2026 at 01:05:32AM +0900, Sang-Heon Jeon wrote:
> Since commit 38607c62b34b ("fs/dax: properly refcount fs dax pages"),
> vmf_insert_mixed_mkwrite() has no callers.
>
> So remove the function and its declaration.
>
> The comment above the function describes the -EBUSY handling in
> __vm_insert_mixed(). Move it above that check.
>
> No functional change.
>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> include/linux/mm.h | 2 --
> mm/memory.c | 16 +++++-----------
> 2 files changed, 5 insertions(+), 13 deletions(-)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index c038d06825c3..2ac734efd4ec 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -5008,8 +5008,6 @@ vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
> unsigned long pfn, pgprot_t pgprot);
> vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
> unsigned long pfn);
> -vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
> - unsigned long addr, unsigned long pfn);
> int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
>
> static inline vm_fault_t vmf_insert_page(struct vm_area_struct *vma,
> diff --git a/mm/memory.c b/mm/memory.c
> index 330cde31bf8b..4b2e4be28031 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3052,6 +3052,11 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
>
> if (err == -ENOMEM)
> return VM_FAULT_OOM;
> + /*
> + * If the insertion of PTE failed because someone else already added a
> + * different entry in the mean time, we treat that as success as we assume
> + * the same entry was actually inserted.
> + */
> if (err < 0 && err != -EBUSY)
> return VM_FAULT_SIGBUS;
>
> @@ -3085,17 +3090,6 @@ vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
> }
> EXPORT_SYMBOL(vmf_insert_mixed);
>
> -/*
> - * If the insertion of PTE failed because someone else already added a
> - * different entry in the mean time, we treat that as success as we assume
> - * the same entry was actually inserted.
> - */
> -vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
> - unsigned long addr, unsigned long pfn)
> -{
> - return __vm_insert_mixed(vma, addr, pfn, true);
> -}
> -
> /*
> * maps a range of physical memory into the requested pages. the old
> * mappings are removed. any references to nonexistent pages results
> --
> 2.43.0
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 2/3] mm/memory: remove the mkwrite argument from __vm_insert_mixed()
2026-10-02 16:05 ` [PATCH v2 2/3] mm/memory: remove the mkwrite argument from __vm_insert_mixed() Sang-Heon Jeon
2026-10-02 18:45 ` SJ Park
2026-10-02 23:34 ` Jose A. Perez de Azpillaga
@ 2026-10-05 2:40 ` Anshuman Khandual
2 siblings, 0 replies; 13+ messages in thread
From: Anshuman Khandual @ 2026-10-05 2:40 UTC (permalink / raw)
To: Sang-Heon Jeon
Cc: Andrew Morton, David Hildenbrand, Jose A . Perez de Azpillaga,
Liam R. Howlett, linux-kernel, linux-mm, Lorenzo Stoakes,
Michal Hocko, Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka
On Sat, Oct 03, 2026 at 01:05:33AM +0900, Sang-Heon Jeon wrote:
> __vm_insert_mixed() is only called from vmf_insert_mixed() with
> mkwrite == false, so mkwrite is also always false in vm_mixed_ok()
> and insert_pfn().
>
> So remove the argument and the unreachable code in insert_pfn().
>
> No functional change.
>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> mm/memory.c | 57 +++++++++++++++++------------------------------------
> 1 file changed, 18 insertions(+), 39 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 4b2e4be28031..6c1d38eba7b2 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -2453,7 +2453,14 @@ static int insert_page_into_pte_locked(struct vm_area_struct *vma, pte_t *pte,
> if (!mkwrite)
> return -EBUSY;
>
> - /* see insert_pfn(). */
> + /*
> + * For read faults on private mappings the PFN passed in may
> + * not match the PFN we have mapped if the mapped PFN is a
> + * writeable COW page. In the mkwrite case we are creating a
> + * writable PTE for a shared mapping and we expect the PFNs to
> + * match. If they don't match, we are likely racing with block
> + * allocation and mapping invalidation.
> + */
> if (pte_pfn(pteval) != page_to_pfn(page)) {
> WARN_ON_ONCE(!is_zero_pfn(pte_pfn(pteval)));
> return -EFAULT;
> @@ -2858,7 +2865,7 @@ int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages,
> EXPORT_SYMBOL(vm_map_pages_zero);
>
> static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr,
> - unsigned long pfn, pgprot_t prot, bool mkwrite)
> + unsigned long pfn, pgprot_t prot)
> {
> struct mm_struct *mm = vma->vm_mm;
> pte_t *pte, entry;
> @@ -2868,38 +2875,12 @@ static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr,
> if (!pte)
> return VM_FAULT_OOM;
> entry = ptep_get(pte);
> - if (!pte_none(entry)) {
> - if (mkwrite) {
> - /*
> - * For read faults on private mappings the PFN passed
> - * in may not match the PFN we have mapped if the
> - * mapped PFN is a writeable COW page. In the mkwrite
> - * case we are creating a writable PTE for a shared
> - * mapping and we expect the PFNs to match. If they
> - * don't match, we are likely racing with block
> - * allocation and mapping invalidation so just skip the
> - * update.
> - */
> - if (pte_pfn(entry) != pfn) {
> - WARN_ON_ONCE(!is_zero_pfn(pte_pfn(entry)));
> - goto out_unlock;
> - }
> - entry = pte_mkyoung(entry);
> - entry = maybe_mkwrite(pte_mkdirty(entry), vma);
> - if (ptep_set_access_flags(vma, addr, pte, entry, 1))
> - update_mmu_cache(vma, addr, pte);
> - }
> + if (!pte_none(entry))
> goto out_unlock;
> - }
>
> /* Ok, finally just insert the thing.. */
> entry = pte_mkspecial(pfn_pte(pfn, prot));
>
> - if (mkwrite) {
> - entry = pte_mkyoung(entry);
> - entry = maybe_mkwrite(pte_mkdirty(entry), vma);
> - }
> -
> set_pte_at(mm, addr, pte, entry);
> update_mmu_cache(vma, addr, pte); /* XXX: why not for insert_page? */
>
> @@ -2967,7 +2948,7 @@ vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
>
> pfnmap_setup_cachemode_pfn(pfn, &pgprot);
>
> - return insert_pfn(vma, addr, pfn, pgprot, false);
> + return insert_pfn(vma, addr, pfn, pgprot);
> }
> EXPORT_SYMBOL(vmf_insert_pfn_prot);
>
> @@ -2998,11 +2979,9 @@ vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
> }
> EXPORT_SYMBOL(vmf_insert_pfn);
>
> -static bool vm_mixed_ok(struct vm_area_struct *vma, unsigned long pfn,
> - bool mkwrite)
> +static bool vm_mixed_ok(struct vm_area_struct *vma, unsigned long pfn)
> {
> - if (unlikely(is_zero_pfn(pfn)) &&
> - (mkwrite || !vm_mixed_zeropage_allowed(vma)))
> + if (unlikely(is_zero_pfn(pfn)) && !vm_mixed_zeropage_allowed(vma))
> return false;
> /* these checks mirror the abort conditions in vm_normal_page */
> if (vma->vm_flags & VM_MIXEDMAP)
> @@ -3013,12 +2992,12 @@ static bool vm_mixed_ok(struct vm_area_struct *vma, unsigned long pfn,
> }
>
> static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
> - unsigned long addr, unsigned long pfn, bool mkwrite)
> + unsigned long addr, unsigned long pfn)
> {
> pgprot_t pgprot = vma->vm_page_prot;
> int err;
>
> - if (!vm_mixed_ok(vma, pfn, mkwrite))
> + if (!vm_mixed_ok(vma, pfn))
> return VM_FAULT_SIGBUS;
>
> if (addr < vma->vm_start || addr >= vma->vm_end)
> @@ -3045,9 +3024,9 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
> * result in pfn_t_has_page() == false.
> */
> page = pfn_to_page(pfn);
> - err = insert_page(vma, addr, page, pgprot, mkwrite);
> + err = insert_page(vma, addr, page, pgprot, false);
> } else {
> - return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
> + return insert_pfn(vma, addr, pfn, pgprot);
> }
>
> if (err == -ENOMEM)
> @@ -3086,7 +3065,7 @@ EXPORT_SYMBOL_GPL(vmf_insert_page_mkwrite);
> vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
> unsigned long pfn)
> {
> - return __vm_insert_mixed(vma, addr, pfn, false);
> + return __vm_insert_mixed(vma, addr, pfn);
> }
> EXPORT_SYMBOL(vmf_insert_mixed);
>
> --
> 2.43.0
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 3/3] mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed()
2026-10-02 16:05 ` [PATCH v2 3/3] mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed() Sang-Heon Jeon
2026-10-02 18:47 ` SJ Park
2026-10-02 23:35 ` Jose A. Perez de Azpillaga
@ 2026-10-05 3:14 ` Anshuman Khandual
2 siblings, 0 replies; 13+ messages in thread
From: Anshuman Khandual @ 2026-10-05 3:14 UTC (permalink / raw)
To: Sang-Heon Jeon
Cc: Andrew Morton, David Hildenbrand, Jose A . Perez de Azpillaga,
Liam R. Howlett, linux-kernel, linux-mm, Lorenzo Stoakes,
Michal Hocko, Mike Rapoport, Suren Baghdasaryan, Vlastimil Babka
On Sat, Oct 03, 2026 at 01:05:34AM +0900, Sang-Heon Jeon wrote:
> vmf_insert_mixed() just calls __vm_insert_mixed() with the same
> arguments.
>
> So merge __vm_insert_mixed() into vmf_insert_mixed().
>
> No functional change.
>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> mm/memory.c | 12 +++---------
> 1 file changed, 3 insertions(+), 9 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index 6c1d38eba7b2..bde650e207c9 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -2991,8 +2991,8 @@ static bool vm_mixed_ok(struct vm_area_struct *vma, unsigned long pfn)
> return false;
> }
>
> -static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
> - unsigned long addr, unsigned long pfn)
> +vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
> + unsigned long pfn)
> {
> pgprot_t pgprot = vma->vm_page_prot;
> int err;
> @@ -3041,6 +3041,7 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
>
> return VM_FAULT_NOPAGE;
> }
> +EXPORT_SYMBOL(vmf_insert_mixed);
>
> vm_fault_t vmf_insert_page_mkwrite(struct vm_fault *vmf, struct page *page,
> bool write)
> @@ -3062,13 +3063,6 @@ vm_fault_t vmf_insert_page_mkwrite(struct vm_fault *vmf, struct page *page,
> }
> EXPORT_SYMBOL_GPL(vmf_insert_page_mkwrite);
>
> -vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
> - unsigned long pfn)
> -{
> - return __vm_insert_mixed(vma, addr, pfn);
> -}
> -EXPORT_SYMBOL(vmf_insert_mixed);
> -
> /*
> * maps a range of physical memory into the requested pages. the old
> * mappings are removed. any references to nonexistent pages results
> --
> 2.43.0
>
^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2026-10-05 3:14 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2026-10-02 16:05 [PATCH v2 0/3] mm/memory: remove unused vmf_insert_mixed_mkwrite() Sang-Heon Jeon
2026-10-02 16:05 ` [PATCH v2 1/3] " Sang-Heon Jeon
2026-10-02 18:35 ` SJ Park
2026-10-02 23:32 ` Jose A. Perez de Azpillaga
2026-10-05 2:36 ` Anshuman Khandual
2026-10-02 16:05 ` [PATCH v2 2/3] mm/memory: remove the mkwrite argument from __vm_insert_mixed() Sang-Heon Jeon
2026-10-02 18:45 ` SJ Park
2026-10-02 23:34 ` Jose A. Perez de Azpillaga
2026-10-05 2:40 ` Anshuman Khandual
2026-10-02 16:05 ` [PATCH v2 3/3] mm/memory: merge __vm_insert_mixed() into vmf_insert_mixed() Sang-Heon Jeon
2026-10-02 18:47 ` SJ Park
2026-10-02 23:35 ` Jose A. Perez de Azpillaga
2026-10-05 3:14 ` Anshuman Khandual
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