2013-06-03 15:31:50

by Zhang Yanfei

Subject: [PATCH 1/3] mm, vmalloc: Only call setup_vmalloc_vm only in __get_vm_area_node

From: Zhang Yanfei <[email protected]>

Now for insert_vmalloc_vm, it only calls the two functions:
- setup_vmalloc_vm: fill vm_struct and vmap_area instances
- clear_vm_unlist: clear VM_UNLIST bit in vm_struct->flags

So in function __get_vm_area_node, if VM_UNLIST bit unset
in flags, that is the else branch here, we don't need to
clear VM_UNLIST bit for vm->flags since this bit is obviously
not set. That is to say, we could only call setup_vmalloc_vm
instead of insert_vmalloc_vm here. And then we could even
remove the if test here.

Signed-off-by: Zhang Yanfei <[email protected]>
---
mm/vmalloc.c | 11 +----------
1 files changed, 1 insertions(+), 10 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d365724..6580c76 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1367,16 +1367,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
return NULL;
}

- /*
- * When this function is called from __vmalloc_node_range,
- * we add VM_UNLIST flag to avoid accessing uninitialized
- * members of vm_struct such as pages and nr_pages fields.
- * They will be set later.
- */
- if (flags & VM_UNLIST)
- setup_vmalloc_vm(area, va, flags, caller);
- else
- insert_vmalloc_vm(area, va, flags, caller);
+ setup_vmalloc_vm(area, va, flags, caller);

return area;
}
--
1.7.1

2013-06-03 15:34:08

by Zhang Yanfei

Subject: [PATCH 2/3] mm, vmalloc: Call setup_vmalloc_vm instead of insert_vmalloc_vm

From: Zhang Yanfei <[email protected]>

Here we pass flags with only VM_ALLOC bit set, it is unnecessary
to call clear_vm_unlist to clear VM_UNLIST bit. So use setup_vmalloc_vm
instead of insert_vmalloc_vm.

Signed-off-by: Zhang Yanfei <[email protected]>
---
mm/vmalloc.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 6580c76..edbfad0 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2503,8 +2503,8 @@ found:

/* insert all vm's */
for (area = 0; area < nr_vms; area++)
- insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
- pcpu_get_vm_areas);
+ setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
+ pcpu_get_vm_areas);

kfree(vas);
return vms;
--
1.7.1

2013-06-03 15:35:17

by Zhang Yanfei

Subject: [PATCH 3/3] mm, vmalloc: Remove insert_vmalloc_vm

From: Zhang Yanfei <[email protected]>

Now this function is nowhere used, we can remove it directly.

Signed-off-by: Zhang Yanfei <[email protected]>
---
mm/vmalloc.c | 7 -------
1 files changed, 0 insertions(+), 7 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index edbfad0..e0a786d 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1322,13 +1322,6 @@ static void clear_vm_unlist(struct vm_struct *vm)
vm->flags &= ~VM_UNLIST;
}

-static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
- unsigned long flags, const void *caller)
-{
- setup_vmalloc_vm(vm, va, flags, caller);
- clear_vm_unlist(vm);
-}
-
static struct vm_struct *__get_vm_area_node(unsigned long size,
unsigned long align, unsigned long flags, unsigned long start,
unsigned long end, int node, gfp_t gfp_mask, const void *caller)
--
1.7.1

2013-06-03 16:13:37

by Joonsoo Kim

Subject: Re: [PATCH 1/3] mm, vmalloc: Only call setup_vmalloc_vm only in __get_vm_area_node

Hello, Zhang.

2013/6/4 Zhang Yanfei <[email protected]>:
> From: Zhang Yanfei <[email protected]>
>
> Now for insert_vmalloc_vm, it only calls the two functions:
> - setup_vmalloc_vm: fill vm_struct and vmap_area instances
> - clear_vm_unlist: clear VM_UNLIST bit in vm_struct->flags
>
> So in function __get_vm_area_node, if VM_UNLIST bit unset
> in flags, that is the else branch here, we don't need to
> clear VM_UNLIST bit for vm->flags since this bit is obviously
> not set. That is to say, we could only call setup_vmalloc_vm
> instead of insert_vmalloc_vm here. And then we could even
> remove the if test here.
>
> Signed-off-by: Zhang Yanfei <[email protected]>

For all three patches,
Acked-by: Joonsoo Kim <[email protected]>

> ---
> mm/vmalloc.c | 11 +----------
> 1 files changed, 1 insertions(+), 10 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index d365724..6580c76 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -1367,16 +1367,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
> return NULL;
> }
>
> - /*
> - * When this function is called from __vmalloc_node_range,
> - * we add VM_UNLIST flag to avoid accessing uninitialized
> - * members of vm_struct such as pages and nr_pages fields.
> - * They will be set later.
> - */
> - if (flags & VM_UNLIST)
> - setup_vmalloc_vm(area, va, flags, caller);
> - else
> - insert_vmalloc_vm(area, va, flags, caller);
> + setup_vmalloc_vm(area, va, flags, caller);
>
> return area;
> }
> --
> 1.7.1