[PATCH 1/1] mmap.c: find_vma: eliminate initial if(mm) check

[PATCH 1/1] mmap.c: find_vma: eliminate initial if(mm) check

[k80c]

As per commit 841e31e5cc6219d62054788faa289b6ed682d068,
we dont really need this if(mm) check anymore.

A WARN_ON_ONCE was added just for safety, but there have been no bug
reports about this so far.

Removing this if(mm) check.

Signed-off-by: k80c <k80ck80c@gmail.com>
---
 mm/mmap.c |    3 ---
 1 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 0db0de1..b2c363f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1935,9 +1935,6 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
 {
 	struct vm_area_struct *vma = NULL;
 
-	if (WARN_ON_ONCE(!mm))		/* Remove this in linux-3.6 */
-		return NULL;
-
 	/* Check the cache first. */
 	/* (Cache hit rate is typically around 35%.) */
 	vma = ACCESS_ONCE(mm->mmap_cache);
-- 
1.7.5.4

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

Re: [PATCH 1/1] mmap.c: find_vma: eliminate initial if(mm) check

[Michel Lespinasse]

On Sun, Apr 7, 2013 at 2:18 AM, k80c <k80ck80c@gmail.com> wrote:
> As per commit 841e31e5cc6219d62054788faa289b6ed682d068,
> we dont really need this if(mm) check anymore.
>
> A WARN_ON_ONCE was added just for safety, but there have been no bug
> reports about this so far.
>
> Removing this if(mm) check.
>
> Signed-off-by: k80c <k80ck80c@gmail.com>
> ---
>  mm/mmap.c |    3 ---
>  1 files changed, 0 insertions(+), 3 deletions(-)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 0db0de1..b2c363f 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -1935,9 +1935,6 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
>  {
>         struct vm_area_struct *vma = NULL;
>
> -       if (WARN_ON_ONCE(!mm))          /* Remove this in linux-3.6 */
> -               return NULL;
> -
>         /* Check the cache first. */
>         /* (Cache hit rate is typically around 35%.) */
>         vma = ACCESS_ONCE(mm->mmap_cache);

Looks good to me.

Reviewed-by: Michel Lespinasse <walken@google.com>

-- 
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

Re: [PATCH 1/1] mmap.c: find_vma: eliminate initial if(mm) check

[Yanfei Zhang]

[-- Attachment #1: Type: text/plain, Size: 1279 bytes --]

I've sent the same patch and has been merged into -mm tree by Andrew Morton.

Thanks
Zhang

2013/4/7 k80c <k80ck80c@gmail.com>

> As per commit 841e31e5cc6219d62054788faa289b6ed682d068,
> we dont really need this if(mm) check anymore.
>
> A WARN_ON_ONCE was added just for safety, but there have been no bug
> reports about this so far.
>
> Removing this if(mm) check.
>
> Signed-off-by: k80c <k80ck80c@gmail.com>
> ---
>  mm/mmap.c |    3 ---
>  1 files changed, 0 insertions(+), 3 deletions(-)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 0db0de1..b2c363f 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -1935,9 +1935,6 @@ struct vm_area_struct *find_vma(struct mm_struct
> *mm, unsigned long addr)
>  {
>         struct vm_area_struct *vma = NULL;
>
> -       if (WARN_ON_ONCE(!mm))          /* Remove this in linux-3.6 */
> -               return NULL;
> -
>         /* Check the cache first. */
>         /* (Cache hit rate is typically around 35%.) */
>         vma = ACCESS_ONCE(mm->mmap_cache);
> --
> 1.7.5.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
>

[-- Attachment #2: Type: text/html, Size: 2072 bytes --]