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

[JoonSoo Kim]

Hello, Zhang.

2013/6/4 Zhang Yanfei <zhangyanfei.yes@xxxxxxxxx>:
> From: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
>
> 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 <zhangyanfei@xxxxxxxxxxxxxx>

For all three patches,
Acked-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

> ---
>  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
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