2019-07-29 14:30:42

by Christoph Hellwig

Subject: [PATCH 8/9] mm: remove the unused MIGRATE_PFN_DEVICE flag

No one ever checks this flag, and we could easily get that information
from the page if needed.

Signed-off-by: Christoph Hellwig <[email protected]>
---
drivers/gpu/drm/nouveau/nouveau_dmem.c | 3 +--
include/linux/migrate.h | 1 -
mm/migrate.c | 4 ++--
3 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 6cb930755970..f04686a2c21f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -582,8 +582,7 @@ static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm,
*dma_addr))
goto out_dma_unmap;

- return migrate_pfn(page_to_pfn(dpage)) |
- MIGRATE_PFN_LOCKED | MIGRATE_PFN_DEVICE;
+ return migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;

out_dma_unmap:
dma_unmap_page(dev, *dma_addr, PAGE_SIZE, DMA_BIDIRECTIONAL);
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 229153c2c496..8b46cfdb1a0e 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -166,7 +166,6 @@ static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
#define MIGRATE_PFN_MIGRATE (1UL << 1)
#define MIGRATE_PFN_LOCKED (1UL << 2)
#define MIGRATE_PFN_WRITE (1UL << 3)
-#define MIGRATE_PFN_DEVICE (1UL << 4)
#define MIGRATE_PFN_SHIFT 6

static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
diff --git a/mm/migrate.c b/mm/migrate.c
index dc4e60a496f2..74735256e260 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2237,8 +2237,8 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
goto next;

page = device_private_entry_to_page(entry);
- mpfn = migrate_pfn(page_to_pfn(page))|
- MIGRATE_PFN_DEVICE | MIGRATE_PFN_MIGRATE;
+ mpfn = migrate_pfn(page_to_pfn(page)) |
+ MIGRATE_PFN_MIGRATE;
if (is_write_device_private_entry(entry))
mpfn |= MIGRATE_PFN_WRITE;
} else {
--
2.20.1

2019-07-30 09:03:24

by Ralph Campbell

Subject: Re: [PATCH 8/9] mm: remove the unused MIGRATE_PFN_DEVICE flag

On 7/29/19 7:28 AM, Christoph Hellwig wrote:
> No one ever checks this flag, and we could easily get that information
> from the page if needed.
>
> Signed-off-by: Christoph Hellwig <[email protected]>

Reviewed-by: Ralph Campbell <[email protected]>

> ---
> drivers/gpu/drm/nouveau/nouveau_dmem.c | 3 +--
> include/linux/migrate.h | 1 -
> mm/migrate.c | 4 ++--
> 3 files changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
> index 6cb930755970..f04686a2c21f 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
> @@ -582,8 +582,7 @@ static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm,
> *dma_addr))
> goto out_dma_unmap;
>
> - return migrate_pfn(page_to_pfn(dpage)) |
> - MIGRATE_PFN_LOCKED | MIGRATE_PFN_DEVICE;
> + return migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
>
> out_dma_unmap:
> dma_unmap_page(dev, *dma_addr, PAGE_SIZE, DMA_BIDIRECTIONAL);
> diff --git a/include/linux/migrate.h b/include/linux/migrate.h
> index 229153c2c496..8b46cfdb1a0e 100644
> --- a/include/linux/migrate.h
> +++ b/include/linux/migrate.h
> @@ -166,7 +166,6 @@ static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
> #define MIGRATE_PFN_MIGRATE (1UL << 1)
> #define MIGRATE_PFN_LOCKED (1UL << 2)
> #define MIGRATE_PFN_WRITE (1UL << 3)
> -#define MIGRATE_PFN_DEVICE (1UL << 4)
> #define MIGRATE_PFN_SHIFT 6
>
> static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
> diff --git a/mm/migrate.c b/mm/migrate.c
> index dc4e60a496f2..74735256e260 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -2237,8 +2237,8 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
> goto next;
>
> page = device_private_entry_to_page(entry);
> - mpfn = migrate_pfn(page_to_pfn(page))|
> - MIGRATE_PFN_DEVICE | MIGRATE_PFN_MIGRATE;
> + mpfn = migrate_pfn(page_to_pfn(page)) |
> + MIGRATE_PFN_MIGRATE;
> if (is_write_device_private_entry(entry))
> mpfn |= MIGRATE_PFN_WRITE;
> } else {
>