* [PATCH v2 0/2] mm/mmap: simplify vma_merge()
@ 2024-01-25 3:49 Yajun Deng
2024-01-25 3:49 ` [PATCH v2 1/2] mm/mmap: pass vma to vma_merge() Yajun Deng
2024-01-25 3:49 ` [PATCH v2 2/2] mm/mmap: remove find_vma_intersection() in vma_merge() Yajun Deng
0 siblings, 2 replies; 5+ messages in thread
From: Yajun Deng @ 2024-01-25 3:49 UTC (permalink / raw
To: akpm
Cc: Liam.Howlett, lstoakes, viro, brauner, vbabka, willy, surenb,
linux-mm, linux-kernel, Yajun Deng
The vma_merge() has too many parameters, we can pass vma to vma_merge(),
so that it can save two parameters.
Since the src vma was passed, find_vma_intersection() can be removed.
v2: split it into two patches.
v1: https://lore.kernel.org/all/20240118082312.2801992-1-yajun.deng@linux.dev/
Yajun Deng (2):
mm/mmap: pass vma to vma_merge()
mm/mmap: remove find_vma_intersection() in vma_merge()
mm/mmap.c | 42 ++++++++++++++++++++++--------------------
1 file changed, 22 insertions(+), 20 deletions(-)
--
2.25.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v2 1/2] mm/mmap: pass vma to vma_merge()
2024-01-25 3:49 [PATCH v2 0/2] mm/mmap: simplify vma_merge() Yajun Deng
@ 2024-01-25 3:49 ` Yajun Deng
2024-01-26 2:25 ` Liam R. Howlett
2024-01-25 3:49 ` [PATCH v2 2/2] mm/mmap: remove find_vma_intersection() in vma_merge() Yajun Deng
1 sibling, 1 reply; 5+ messages in thread
From: Yajun Deng @ 2024-01-25 3:49 UTC (permalink / raw
To: akpm
Cc: Liam.Howlett, lstoakes, viro, brauner, vbabka, willy, surenb,
linux-mm, linux-kernel, Yajun Deng
These vma_merge() callers will pass mm, anon_vma and file, they all from
the same vma. There is no need to pass three parameters at the same time.
Pass vma instead of mm, anon_vma and file to vma_merge(), so that it can
save two parameters.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
mm/mmap.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 49d25172eac8..f19bc53bc08e 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -860,13 +860,15 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
* area is returned, or the function will return NULL
*/
static struct vm_area_struct
-*vma_merge(struct vma_iterator *vmi, struct mm_struct *mm,
- struct vm_area_struct *prev, unsigned long addr, unsigned long end,
- unsigned long vm_flags, struct anon_vma *anon_vma, struct file *file,
- pgoff_t pgoff, struct mempolicy *policy,
+*vma_merge(struct vma_iterator *vmi, struct vm_area_struct *prev,
+ struct vm_area_struct *src, unsigned long addr, unsigned long end,
+ unsigned long vm_flags, pgoff_t pgoff, struct mempolicy *policy,
struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
struct anon_vma_name *anon_name)
{
+ struct mm_struct *mm = src->vm_mm;
+ struct anon_vma *anon_vma = src->anon_vma;
+ struct file *file = src->vm_file;
struct vm_area_struct *curr, *next, *res;
struct vm_area_struct *vma, *adjust, *remove, *remove2;
struct vm_area_struct *anon_dup = NULL;
@@ -2424,9 +2426,8 @@ struct vm_area_struct *vma_modify(struct vma_iterator *vmi,
pgoff_t pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
struct vm_area_struct *merged;
- merged = vma_merge(vmi, vma->vm_mm, prev, start, end, vm_flags,
- vma->anon_vma, vma->vm_file, pgoff, policy,
- uffd_ctx, anon_name);
+ merged = vma_merge(vmi, prev, vma, start, end, vm_flags,
+ pgoff, policy, uffd_ctx, anon_name);
if (merged)
return merged;
@@ -2456,9 +2457,8 @@ static struct vm_area_struct
struct vm_area_struct *vma, unsigned long start,
unsigned long end, pgoff_t pgoff)
{
- return vma_merge(vmi, vma->vm_mm, prev, start, end, vma->vm_flags,
- vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
- vma->vm_userfaultfd_ctx, anon_vma_name(vma));
+ return vma_merge(vmi, prev, vma, start, end, vma->vm_flags, pgoff,
+ vma_policy(vma), vma->vm_userfaultfd_ctx, anon_vma_name(vma));
}
/*
@@ -2472,10 +2472,9 @@ struct vm_area_struct *vma_merge_extend(struct vma_iterator *vmi,
pgoff_t pgoff = vma->vm_pgoff + vma_pages(vma);
/* vma is specified as prev, so case 1 or 2 will apply. */
- return vma_merge(vmi, vma->vm_mm, vma, vma->vm_end, vma->vm_end + delta,
- vma->vm_flags, vma->anon_vma, vma->vm_file, pgoff,
- vma_policy(vma), vma->vm_userfaultfd_ctx,
- anon_vma_name(vma));
+ return vma_merge(vmi, vma, vma, vma->vm_end, vma->vm_end + delta,
+ vma->vm_flags, pgoff, vma_policy(vma),
+ vma->vm_userfaultfd_ctx, anon_vma_name(vma));
}
/*
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 2/2] mm/mmap: remove find_vma_intersection() in vma_merge()
2024-01-25 3:49 [PATCH v2 0/2] mm/mmap: simplify vma_merge() Yajun Deng
2024-01-25 3:49 ` [PATCH v2 1/2] mm/mmap: pass vma to vma_merge() Yajun Deng
@ 2024-01-25 3:49 ` Yajun Deng
2024-01-26 2:28 ` Liam R. Howlett
1 sibling, 1 reply; 5+ messages in thread
From: Yajun Deng @ 2024-01-25 3:49 UTC (permalink / raw
To: akpm
Cc: Liam.Howlett, lstoakes, viro, brauner, vbabka, willy, surenb,
linux-mm, linux-kernel, Yajun Deng
We need to find the current vma by find_vma_intersection() in
vma_merge(). Since the src vma was passed, we can add a check to figure
out if the current vma is NULL or the src vma directly.
Remove find_vma_intersection() in vma_merge(). And initialize the next to
NULL when defining it.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
mm/mmap.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index f19bc53bc08e..ea02fdc91aa2 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -869,7 +869,7 @@ static struct vm_area_struct
struct mm_struct *mm = src->vm_mm;
struct anon_vma *anon_vma = src->anon_vma;
struct file *file = src->vm_file;
- struct vm_area_struct *curr, *next, *res;
+ struct vm_area_struct *curr = src, *next = NULL, *res;
struct vm_area_struct *vma, *adjust, *remove, *remove2;
struct vm_area_struct *anon_dup = NULL;
struct vma_prepare vp;
@@ -890,14 +890,18 @@ static struct vm_area_struct
if (vm_flags & VM_SPECIAL)
return NULL;
- /* Does the input range span an existing VMA? (cases 5 - 8) */
- curr = find_vma_intersection(mm, prev ? prev->vm_end : 0, end);
+ /*
+ * If the current vma and the prev vma are the same vma, it
+ * means the current vma is NULL.
+ * Does the input range span an existing VMA? (cases 5 - 8)
+ */
+ if (prev == curr || addr != curr->vm_start || end > curr->vm_end)
+ curr = NULL;
if (!curr || /* cases 1 - 4 */
end == curr->vm_end) /* cases 6 - 8, adjacent VMA */
next = vma_lookup(mm, end);
- else
- next = NULL; /* case 5 */
+ /* case 5 set to NULL above */
if (prev) {
vma_start = prev->vm_start;
@@ -921,7 +925,6 @@ static struct vm_area_struct
/* Verify some invariant that must be enforced by the caller. */
VM_WARN_ON(prev && addr <= prev->vm_start);
- VM_WARN_ON(curr && (addr != curr->vm_start || end > curr->vm_end));
VM_WARN_ON(addr >= end);
if (!merge_prev && !merge_next)
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2 1/2] mm/mmap: pass vma to vma_merge()
2024-01-25 3:49 ` [PATCH v2 1/2] mm/mmap: pass vma to vma_merge() Yajun Deng
@ 2024-01-26 2:25 ` Liam R. Howlett
0 siblings, 0 replies; 5+ messages in thread
From: Liam R. Howlett @ 2024-01-26 2:25 UTC (permalink / raw
To: Yajun Deng
Cc: akpm, lstoakes, viro, brauner, vbabka, willy, surenb, linux-mm,
linux-kernel
* Yajun Deng <yajun.deng@linux.dev> [240124 22:49]:
> These vma_merge() callers will pass mm, anon_vma and file, they all from
> the same vma. There is no need to pass three parameters at the same time.
>
> Pass vma instead of mm, anon_vma and file to vma_merge(), so that it can
> save two parameters.
>
> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Thanks for splitting these up.
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> ---
> mm/mmap.c | 27 +++++++++++++--------------
> 1 file changed, 13 insertions(+), 14 deletions(-)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 49d25172eac8..f19bc53bc08e 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -860,13 +860,15 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
> * area is returned, or the function will return NULL
> */
> static struct vm_area_struct
> -*vma_merge(struct vma_iterator *vmi, struct mm_struct *mm,
> - struct vm_area_struct *prev, unsigned long addr, unsigned long end,
> - unsigned long vm_flags, struct anon_vma *anon_vma, struct file *file,
> - pgoff_t pgoff, struct mempolicy *policy,
> +*vma_merge(struct vma_iterator *vmi, struct vm_area_struct *prev,
> + struct vm_area_struct *src, unsigned long addr, unsigned long end,
> + unsigned long vm_flags, pgoff_t pgoff, struct mempolicy *policy,
> struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
> struct anon_vma_name *anon_name)
> {
> + struct mm_struct *mm = src->vm_mm;
> + struct anon_vma *anon_vma = src->anon_vma;
> + struct file *file = src->vm_file;
> struct vm_area_struct *curr, *next, *res;
> struct vm_area_struct *vma, *adjust, *remove, *remove2;
> struct vm_area_struct *anon_dup = NULL;
> @@ -2424,9 +2426,8 @@ struct vm_area_struct *vma_modify(struct vma_iterator *vmi,
> pgoff_t pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
> struct vm_area_struct *merged;
>
> - merged = vma_merge(vmi, vma->vm_mm, prev, start, end, vm_flags,
> - vma->anon_vma, vma->vm_file, pgoff, policy,
> - uffd_ctx, anon_name);
> + merged = vma_merge(vmi, prev, vma, start, end, vm_flags,
> + pgoff, policy, uffd_ctx, anon_name);
> if (merged)
> return merged;
>
> @@ -2456,9 +2457,8 @@ static struct vm_area_struct
> struct vm_area_struct *vma, unsigned long start,
> unsigned long end, pgoff_t pgoff)
> {
> - return vma_merge(vmi, vma->vm_mm, prev, start, end, vma->vm_flags,
> - vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
> - vma->vm_userfaultfd_ctx, anon_vma_name(vma));
> + return vma_merge(vmi, prev, vma, start, end, vma->vm_flags, pgoff,
> + vma_policy(vma), vma->vm_userfaultfd_ctx, anon_vma_name(vma));
> }
>
> /*
> @@ -2472,10 +2472,9 @@ struct vm_area_struct *vma_merge_extend(struct vma_iterator *vmi,
> pgoff_t pgoff = vma->vm_pgoff + vma_pages(vma);
>
> /* vma is specified as prev, so case 1 or 2 will apply. */
> - return vma_merge(vmi, vma->vm_mm, vma, vma->vm_end, vma->vm_end + delta,
> - vma->vm_flags, vma->anon_vma, vma->vm_file, pgoff,
> - vma_policy(vma), vma->vm_userfaultfd_ctx,
> - anon_vma_name(vma));
> + return vma_merge(vmi, vma, vma, vma->vm_end, vma->vm_end + delta,
> + vma->vm_flags, pgoff, vma_policy(vma),
> + vma->vm_userfaultfd_ctx, anon_vma_name(vma));
> }
>
> /*
> --
> 2.25.1
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 2/2] mm/mmap: remove find_vma_intersection() in vma_merge()
2024-01-25 3:49 ` [PATCH v2 2/2] mm/mmap: remove find_vma_intersection() in vma_merge() Yajun Deng
@ 2024-01-26 2:28 ` Liam R. Howlett
0 siblings, 0 replies; 5+ messages in thread
From: Liam R. Howlett @ 2024-01-26 2:28 UTC (permalink / raw
To: Yajun Deng
Cc: akpm, lstoakes, viro, brauner, vbabka, willy, surenb, linux-mm,
linux-kernel
* Yajun Deng <yajun.deng@linux.dev> [240124 22:50]:
> We need to find the current vma by find_vma_intersection() in
> vma_merge(). Since the src vma was passed, we can add a check to figure
> out if the current vma is NULL or the src vma directly.
>
> Remove find_vma_intersection() in vma_merge(). And initialize the next to
> NULL when defining it.
>
> Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> ---
> mm/mmap.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index f19bc53bc08e..ea02fdc91aa2 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -869,7 +869,7 @@ static struct vm_area_struct
> struct mm_struct *mm = src->vm_mm;
> struct anon_vma *anon_vma = src->anon_vma;
> struct file *file = src->vm_file;
> - struct vm_area_struct *curr, *next, *res;
> + struct vm_area_struct *curr = src, *next = NULL, *res;
> struct vm_area_struct *vma, *adjust, *remove, *remove2;
> struct vm_area_struct *anon_dup = NULL;
> struct vma_prepare vp;
> @@ -890,14 +890,18 @@ static struct vm_area_struct
> if (vm_flags & VM_SPECIAL)
> return NULL;
>
> - /* Does the input range span an existing VMA? (cases 5 - 8) */
> - curr = find_vma_intersection(mm, prev ? prev->vm_end : 0, end);
> + /*
> + * If the current vma and the prev vma are the same vma, it
> + * means the current vma is NULL.
> + * Does the input range span an existing VMA? (cases 5 - 8)
> + */
> + if (prev == curr || addr != curr->vm_start || end > curr->vm_end)
> + curr = NULL;
>
> if (!curr || /* cases 1 - 4 */
> end == curr->vm_end) /* cases 6 - 8, adjacent VMA */
> next = vma_lookup(mm, end);
> - else
> - next = NULL; /* case 5 */
> + /* case 5 set to NULL above */
>
> if (prev) {
> vma_start = prev->vm_start;
> @@ -921,7 +925,6 @@ static struct vm_area_struct
>
> /* Verify some invariant that must be enforced by the caller. */
> VM_WARN_ON(prev && addr <= prev->vm_start);
> - VM_WARN_ON(curr && (addr != curr->vm_start || end > curr->vm_end));
> VM_WARN_ON(addr >= end);
>
> if (!merge_prev && !merge_next)
> --
> 2.25.1
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-01-26 3:45 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-01-25 3:49 [PATCH v2 0/2] mm/mmap: simplify vma_merge() Yajun Deng
2024-01-25 3:49 ` [PATCH v2 1/2] mm/mmap: pass vma to vma_merge() Yajun Deng
2024-01-26 2:25 ` Liam R. Howlett
2024-01-25 3:49 ` [PATCH v2 2/2] mm/mmap: remove find_vma_intersection() in vma_merge() Yajun Deng
2024-01-26 2:28 ` Liam R. Howlett
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).