2021-05-19 18:33:32

by Souptick Joarder

Subject: [PATCH] mm/huge_memory.c: Remove unused variable unmap_success

Kernel test robot throws below warning ->

mm/huge_memory.c: In function 'unmap_page':
>> mm/huge_memory.c:2345:7: warning: variable 'unmap_success' set but not used [-Wunused-but-set-variable]
2345 | bool unmap_success;
| ^~~~~~~~~~~~~

Remove the unused variable unmap_success.

Reported-by: kernel test robot <[email protected]>
Signed-off-by: Souptick Joarder <[email protected]>
---
mm/huge_memory.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 52ca04b905cf..ff79a12993c9 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2342,14 +2342,13 @@ static void unmap_page(struct page *page)
{
enum ttu_flags ttu_flags = TTU_IGNORE_MLOCK |
TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD;
- bool unmap_success;

VM_BUG_ON_PAGE(!PageHead(page), page);

if (PageAnon(page))
ttu_flags |= TTU_SPLIT_FREEZE;

- unmap_success = try_to_unmap(page, ttu_flags);
+ try_to_unmap(page, ttu_flags);
}

static void remap_page(struct page *page, unsigned int nr)
--
2.25.1

2021-05-19 18:34:06

by Yang Shi

Subject: Re: [PATCH] mm/huge_memory.c: Remove unused variable unmap_success

On Tue, May 18, 2021 at 1:19 PM Yang Shi <[email protected]> wrote:
>
> On Tue, May 18, 2021 at 1:09 PM Souptick Joarder <[email protected]> wrote:
> >
> > Kernel test robot throws below warning ->
> >
> > mm/huge_memory.c: In function 'unmap_page':
> > >> mm/huge_memory.c:2345:7: warning: variable 'unmap_success' set but not used [-Wunused-but-set-variable]
> > 2345 | bool unmap_success;
> > | ^~~~~~~~~~~~~
> >
> > Remove the unused variable unmap_success.
> >
> > Reported-by: kernel test robot <[email protected]>
> > Signed-off-by: Souptick Joarder <[email protected]>
>
> Thanks for catching this. Reviewed-by: Yang Shi <[email protected]>
>
> Just like https://lore.kernel.org/linux-mm/CAHbLzkonsd9f=48+cxKOJamNb9e8qpvWJCYDGFB_wNTdET2zmQ@mail.gmail.com/T/#t,
> not sure why my compiler didn't catch such warning.

I just found out my build has "-Wno-unused-but-set-variable". This
explains why I didn't catch it.

> > ---
> > mm/huge_memory.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> > index 52ca04b905cf..ff79a12993c9 100644
> > --- a/mm/huge_memory.c
> > +++ b/mm/huge_memory.c
> > @@ -2342,14 +2342,13 @@ static void unmap_page(struct page *page)
> > {
> > enum ttu_flags ttu_flags = TTU_IGNORE_MLOCK |
> > TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD;
> > - bool unmap_success;
> >
> > VM_BUG_ON_PAGE(!PageHead(page), page);
> >
> > if (PageAnon(page))
> > ttu_flags |= TTU_SPLIT_FREEZE;
> >
> > - unmap_success = try_to_unmap(page, ttu_flags);
> > + try_to_unmap(page, ttu_flags);
> > }
> >
> > static void remap_page(struct page *page, unsigned int nr)
> > --
> > 2.25.1
> >
> >

2021-05-19 21:05:57

by Yang Shi

Subject: Re: [PATCH] mm/huge_memory.c: Remove unused variable unmap_success

On Tue, May 18, 2021 at 1:09 PM Souptick Joarder <[email protected]> wrote:
>
> Kernel test robot throws below warning ->
>
> mm/huge_memory.c: In function 'unmap_page':
> >> mm/huge_memory.c:2345:7: warning: variable 'unmap_success' set but not used [-Wunused-but-set-variable]
> 2345 | bool unmap_success;
> | ^~~~~~~~~~~~~
>
> Remove the unused variable unmap_success.
>
> Reported-by: kernel test robot <[email protected]>
> Signed-off-by: Souptick Joarder <[email protected]>

Thanks for catching this. Reviewed-by: Yang Shi <[email protected]>

Just like https://lore.kernel.org/linux-mm/CAHbLzkonsd9f=48+cxKOJamNb9e8qpvWJCYDGFB_wNTdET2zmQ@mail.gmail.com/T/#t,
not sure why my compiler didn't catch such warning.
> ---
> mm/huge_memory.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 52ca04b905cf..ff79a12993c9 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2342,14 +2342,13 @@ static void unmap_page(struct page *page)
> {
> enum ttu_flags ttu_flags = TTU_IGNORE_MLOCK |
> TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD;
> - bool unmap_success;
>
> VM_BUG_ON_PAGE(!PageHead(page), page);
>
> if (PageAnon(page))
> ttu_flags |= TTU_SPLIT_FREEZE;
>
> - unmap_success = try_to_unmap(page, ttu_flags);
> + try_to_unmap(page, ttu_flags);
> }
>
> static void remap_page(struct page *page, unsigned int nr)
> --
> 2.25.1
>
>

2021-05-25 10:06:11

by David Hildenbrand

Subject: Re: [PATCH] mm/huge_memory.c: Remove unused variable unmap_success

On 18.05.21 22:09, Souptick Joarder wrote:
> Kernel test robot throws below warning ->
>
> mm/huge_memory.c: In function 'unmap_page':
>>> mm/huge_memory.c:2345:7: warning: variable 'unmap_success' set but not used [-Wunused-but-set-variable]
> 2345 | bool unmap_success;
> | ^~~~~~~~~~~~~
>
> Remove the unused variable unmap_success.
>
> Reported-by: kernel test robot <[email protected]>
> Signed-off-by: Souptick Joarder <[email protected]>
> ---
> mm/huge_memory.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 52ca04b905cf..ff79a12993c9 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2342,14 +2342,13 @@ static void unmap_page(struct page *page)
> {
> enum ttu_flags ttu_flags = TTU_IGNORE_MLOCK |
> TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD;
> - bool unmap_success;
>
> VM_BUG_ON_PAGE(!PageHead(page), page);
>
> if (PageAnon(page))
> ttu_flags |= TTU_SPLIT_FREEZE;
>
> - unmap_success = try_to_unmap(page, ttu_flags);
> + try_to_unmap(page, ttu_flags);
> }
>
> static void remap_page(struct page *page, unsigned int nr)
>

Reviewed-by: David Hildenbrand <[email protected]>

--
Thanks,

David / dhildenb