* Re: [PATCH] mm/vma: small VMA lock cleanups
2025-10-24 9:09 [PATCH] mm/vma: small VMA lock cleanups Lorenzo Stoakes
@ 2025-10-28 0:49 ` Suren Baghdasaryan
2025-10-28 17:59 ` Shakeel Butt
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Suren Baghdasaryan @ 2025-10-28 0:49 UTC (permalink / raw)
To: Lorenzo Stoakes
Cc: Andrew Morton, Liam R . Howlett, Vlastimil Babka, Shakeel Butt,
linux-mm, linux-kernel
On Fri, Oct 24, 2025 at 2:09 AM Lorenzo Stoakes
<lorenzo.stoakes@oracle.com> wrote:
>
> We declare vma_start_read() as a static function in mm/mmap_lock.c, so
> there is no need to provide a stub for !CONFIG_PER_VMA_LOCK.
>
> __is_vma_write_locked() is declared in a header and should therefore be static
> inline.
>
> Put parens around (refcnt & VMA_LOCK_OFFSET) in is_vma_writer_only() to make
> precedence clear.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Thanks for cleaning this up!
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
> ---
> include/linux/mmap_lock.h | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
> index 2c9fffa58714..e05da70dc0cb 100644
> --- a/include/linux/mmap_lock.h
> +++ b/include/linux/mmap_lock.h
> @@ -130,7 +130,7 @@ static inline bool is_vma_writer_only(int refcnt)
> * a detached vma happens only in vma_mark_detached() and is a rare
> * case, therefore most of the time there will be no unnecessary wakeup.
> */
> - return refcnt & VMA_LOCK_OFFSET && refcnt <= VMA_LOCK_OFFSET + 1;
> + return (refcnt & VMA_LOCK_OFFSET) && refcnt <= VMA_LOCK_OFFSET + 1;
> }
>
> static inline void vma_refcount_put(struct vm_area_struct *vma)
> @@ -183,7 +183,7 @@ static inline void vma_end_read(struct vm_area_struct *vma)
> }
>
> /* WARNING! Can only be used if mmap_lock is expected to be write-locked */
> -static bool __is_vma_write_locked(struct vm_area_struct *vma, unsigned int *mm_lock_seq)
> +static inline bool __is_vma_write_locked(struct vm_area_struct *vma, unsigned int *mm_lock_seq)
> {
> mmap_assert_write_locked(vma->vm_mm);
>
> @@ -281,9 +281,6 @@ static inline bool mmap_lock_speculate_retry(struct mm_struct *mm, unsigned int
> return true;
> }
> static inline void vma_lock_init(struct vm_area_struct *vma, bool reset_refcnt) {}
> -static inline struct vm_area_struct *vma_start_read(struct mm_struct *mm,
> - struct vm_area_struct *vma)
> - { return NULL; }
> static inline void vma_end_read(struct vm_area_struct *vma) {}
> static inline void vma_start_write(struct vm_area_struct *vma) {}
> static inline void vma_assert_write_locked(struct vm_area_struct *vma)
> --
> 2.51.0
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] mm/vma: small VMA lock cleanups
2025-10-24 9:09 [PATCH] mm/vma: small VMA lock cleanups Lorenzo Stoakes
2025-10-28 0:49 ` Suren Baghdasaryan
@ 2025-10-28 17:59 ` Shakeel Butt
2025-10-29 8:02 ` Vlastimil Babka
2025-10-31 15:55 ` Liam R. Howlett
3 siblings, 0 replies; 5+ messages in thread
From: Shakeel Butt @ 2025-10-28 17:59 UTC (permalink / raw)
To: Lorenzo Stoakes
Cc: Andrew Morton, Suren Baghdasaryan, Liam R . Howlett,
Vlastimil Babka, linux-mm, linux-kernel
On Fri, Oct 24, 2025 at 10:09:02AM +0100, Lorenzo Stoakes wrote:
> We declare vma_start_read() as a static function in mm/mmap_lock.c, so
> there is no need to provide a stub for !CONFIG_PER_VMA_LOCK.
>
> __is_vma_write_locked() is declared in a header and should therefore be static
> inline.
>
> Put parens around (refcnt & VMA_LOCK_OFFSET) in is_vma_writer_only() to make
> precedence clear.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] mm/vma: small VMA lock cleanups
2025-10-24 9:09 [PATCH] mm/vma: small VMA lock cleanups Lorenzo Stoakes
2025-10-28 0:49 ` Suren Baghdasaryan
2025-10-28 17:59 ` Shakeel Butt
@ 2025-10-29 8:02 ` Vlastimil Babka
2025-10-31 15:55 ` Liam R. Howlett
3 siblings, 0 replies; 5+ messages in thread
From: Vlastimil Babka @ 2025-10-29 8:02 UTC (permalink / raw)
To: Lorenzo Stoakes, Andrew Morton
Cc: Suren Baghdasaryan, Liam R . Howlett, Shakeel Butt, linux-mm,
linux-kernel
On 10/24/25 11:09, Lorenzo Stoakes wrote:
> We declare vma_start_read() as a static function in mm/mmap_lock.c, so
> there is no need to provide a stub for !CONFIG_PER_VMA_LOCK.
>
> __is_vma_write_locked() is declared in a header and should therefore be static
> inline.
>
> Put parens around (refcnt & VMA_LOCK_OFFSET) in is_vma_writer_only() to make
> precedence clear.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
> ---
> include/linux/mmap_lock.h | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
> index 2c9fffa58714..e05da70dc0cb 100644
> --- a/include/linux/mmap_lock.h
> +++ b/include/linux/mmap_lock.h
> @@ -130,7 +130,7 @@ static inline bool is_vma_writer_only(int refcnt)
> * a detached vma happens only in vma_mark_detached() and is a rare
> * case, therefore most of the time there will be no unnecessary wakeup.
> */
> - return refcnt & VMA_LOCK_OFFSET && refcnt <= VMA_LOCK_OFFSET + 1;
> + return (refcnt & VMA_LOCK_OFFSET) && refcnt <= VMA_LOCK_OFFSET + 1;
> }
>
> static inline void vma_refcount_put(struct vm_area_struct *vma)
> @@ -183,7 +183,7 @@ static inline void vma_end_read(struct vm_area_struct *vma)
> }
>
> /* WARNING! Can only be used if mmap_lock is expected to be write-locked */
> -static bool __is_vma_write_locked(struct vm_area_struct *vma, unsigned int *mm_lock_seq)
> +static inline bool __is_vma_write_locked(struct vm_area_struct *vma, unsigned int *mm_lock_seq)
> {
> mmap_assert_write_locked(vma->vm_mm);
>
> @@ -281,9 +281,6 @@ static inline bool mmap_lock_speculate_retry(struct mm_struct *mm, unsigned int
> return true;
> }
> static inline void vma_lock_init(struct vm_area_struct *vma, bool reset_refcnt) {}
> -static inline struct vm_area_struct *vma_start_read(struct mm_struct *mm,
> - struct vm_area_struct *vma)
> - { return NULL; }
> static inline void vma_end_read(struct vm_area_struct *vma) {}
> static inline void vma_start_write(struct vm_area_struct *vma) {}
> static inline void vma_assert_write_locked(struct vm_area_struct *vma)
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] mm/vma: small VMA lock cleanups
2025-10-24 9:09 [PATCH] mm/vma: small VMA lock cleanups Lorenzo Stoakes
` (2 preceding siblings ...)
2025-10-29 8:02 ` Vlastimil Babka
@ 2025-10-31 15:55 ` Liam R. Howlett
3 siblings, 0 replies; 5+ messages in thread
From: Liam R. Howlett @ 2025-10-31 15:55 UTC (permalink / raw)
To: Lorenzo Stoakes
Cc: Andrew Morton, Suren Baghdasaryan, Vlastimil Babka, Shakeel Butt,
linux-mm, linux-kernel
* Lorenzo Stoakes <lorenzo.stoakes@oracle.com> [251024 05:09]:
> We declare vma_start_read() as a static function in mm/mmap_lock.c, so
> there is no need to provide a stub for !CONFIG_PER_VMA_LOCK.
>
> __is_vma_write_locked() is declared in a header and should therefore be static
> inline.
>
> Put parens around (refcnt & VMA_LOCK_OFFSET) in is_vma_writer_only() to make
> precedence clear.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> ---
> include/linux/mmap_lock.h | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
> index 2c9fffa58714..e05da70dc0cb 100644
> --- a/include/linux/mmap_lock.h
> +++ b/include/linux/mmap_lock.h
> @@ -130,7 +130,7 @@ static inline bool is_vma_writer_only(int refcnt)
> * a detached vma happens only in vma_mark_detached() and is a rare
> * case, therefore most of the time there will be no unnecessary wakeup.
> */
> - return refcnt & VMA_LOCK_OFFSET && refcnt <= VMA_LOCK_OFFSET + 1;
> + return (refcnt & VMA_LOCK_OFFSET) && refcnt <= VMA_LOCK_OFFSET + 1;
> }
>
> static inline void vma_refcount_put(struct vm_area_struct *vma)
> @@ -183,7 +183,7 @@ static inline void vma_end_read(struct vm_area_struct *vma)
> }
>
> /* WARNING! Can only be used if mmap_lock is expected to be write-locked */
> -static bool __is_vma_write_locked(struct vm_area_struct *vma, unsigned int *mm_lock_seq)
> +static inline bool __is_vma_write_locked(struct vm_area_struct *vma, unsigned int *mm_lock_seq)
> {
> mmap_assert_write_locked(vma->vm_mm);
>
> @@ -281,9 +281,6 @@ static inline bool mmap_lock_speculate_retry(struct mm_struct *mm, unsigned int
> return true;
> }
> static inline void vma_lock_init(struct vm_area_struct *vma, bool reset_refcnt) {}
> -static inline struct vm_area_struct *vma_start_read(struct mm_struct *mm,
> - struct vm_area_struct *vma)
> - { return NULL; }
> static inline void vma_end_read(struct vm_area_struct *vma) {}
> static inline void vma_start_write(struct vm_area_struct *vma) {}
> static inline void vma_assert_write_locked(struct vm_area_struct *vma)
> --
> 2.51.0
>
^ permalink raw reply [flat|nested] 5+ messages in thread