2019-05-02 13:20:09

by Anshuman Khandual

[permalink] [raw]
Subject: [PATCH] mm/pgtable: Drop pgtable_t variable from pte_fn_t functions

Drop the pgtable_t variable from all implementation for pte_fn_t as none of
them use it. apply_to_pte_range() should stop computing it as well. Should
help us save some cycles.

Signed-off-by: Anshuman Khandual <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Russell King <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Logan Gunthorpe <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
- Boot tested on arm64 and x86 platforms.
- Build tested on multiple platforms with their defconfig

arch/arm/kernel/efi.c | 3 +--
arch/arm/mm/dma-mapping.c | 3 +--
arch/arm/mm/pageattr.c | 3 +--
arch/arm64/kernel/efi.c | 3 +--
arch/arm64/mm/pageattr.c | 3 +--
arch/x86/xen/mmu_pv.c | 3 +--
drivers/gpu/drm/i915/i915_mm.c | 3 +--
drivers/xen/gntdev.c | 6 ++----
drivers/xen/privcmd.c | 6 ++----
drivers/xen/xlate_mmu.c | 3 +--
include/linux/mm.h | 3 +--
mm/memory.c | 5 +----
mm/vmalloc.c | 2 +-
13 files changed, 15 insertions(+), 31 deletions(-)

diff --git a/arch/arm/kernel/efi.c b/arch/arm/kernel/efi.c
index 9f43ba012d10..b1f142a01f2f 100644
--- a/arch/arm/kernel/efi.c
+++ b/arch/arm/kernel/efi.c
@@ -11,8 +11,7 @@
#include <asm/mach/map.h>
#include <asm/mmu_context.h>

-static int __init set_permissions(pte_t *ptep, pgtable_t token,
- unsigned long addr, void *data)
+static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
{
efi_memory_desc_t *md = data;
pte_t pte = *ptep;
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 43f46aa7ef33..739286511a18 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -496,8 +496,7 @@ void __init dma_contiguous_remap(void)
}
}

-static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr,
- void *data)
+static int __dma_update_pte(pte_t *pte, unsigned long addr, void *data)
{
struct page *page = virt_to_page(addr);
pgprot_t prot = *(pgprot_t *)data;
diff --git a/arch/arm/mm/pageattr.c b/arch/arm/mm/pageattr.c
index 1403cb4a0c3d..c8b500940e1f 100644
--- a/arch/arm/mm/pageattr.c
+++ b/arch/arm/mm/pageattr.c
@@ -22,8 +22,7 @@ struct page_change_data {
pgprot_t clear_mask;
};

-static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr,
- void *data)
+static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
{
struct page_change_data *cdata = data;
pte_t pte = *ptep;
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index 4f9acb5fbe97..230cff073a08 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -86,8 +86,7 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
return 0;
}

-static int __init set_permissions(pte_t *ptep, pgtable_t token,
- unsigned long addr, void *data)
+static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
{
efi_memory_desc_t *md = data;
pte_t pte = READ_ONCE(*ptep);
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index 6cd645edcf35..0be077628b21 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -27,8 +27,7 @@ struct page_change_data {

bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED);

-static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr,
- void *data)
+static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
{
struct page_change_data *cdata = data;
pte_t pte = READ_ONCE(*ptep);
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index a21e1734fc1f..308a6195fd26 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -2702,8 +2702,7 @@ struct remap_data {
struct mmu_update *mmu_update;
};

-static int remap_area_pfn_pte_fn(pte_t *ptep, pgtable_t token,
- unsigned long addr, void *data)
+static int remap_area_pfn_pte_fn(pte_t *ptep, unsigned long addr, void *data)
{
struct remap_data *rmd = data;
pte_t pte = pte_mkspecial(mfn_pte(*rmd->pfn, rmd->prot));
diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c
index e4935dd1fd37..c23bb29e6d3e 100644
--- a/drivers/gpu/drm/i915/i915_mm.c
+++ b/drivers/gpu/drm/i915/i915_mm.c
@@ -35,8 +35,7 @@ struct remap_pfn {
pgprot_t prot;
};

-static int remap_pfn(pte_t *pte, pgtable_t token,
- unsigned long addr, void *data)
+static int remap_pfn(pte_t *pte, unsigned long addr, void *data)
{
struct remap_pfn *r = data;

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 7cf9c51318aa..f0df481e2697 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -264,8 +264,7 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map)

/* ------------------------------------------------------------------ */

-static int find_grant_ptes(pte_t *pte, pgtable_t token,
- unsigned long addr, void *data)
+static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data)
{
struct gntdev_grant_map *map = data;
unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
@@ -292,8 +291,7 @@ static int find_grant_ptes(pte_t *pte, pgtable_t token,
}

#ifdef CONFIG_X86
-static int set_grant_ptes_as_special(pte_t *pte, pgtable_t token,
- unsigned long addr, void *data)
+static int set_grant_ptes_as_special(pte_t *pte, unsigned long addr, void *data)
{
set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte));
return 0;
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index b24ddac1604b..4c7268869e2c 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -730,8 +730,7 @@ struct remap_pfn {
unsigned long i;
};

-static int remap_pfn_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
- void *data)
+static int remap_pfn_fn(pte_t *ptep, unsigned long addr, void *data)
{
struct remap_pfn *r = data;
struct page *page = r->pages[r->i];
@@ -965,8 +964,7 @@ static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
* on a per pfn/pte basis. Mapping calls that fail with ENOENT
* can be then retried until success.
*/
-static int is_mapped_fn(pte_t *pte, struct page *pmd_page,
- unsigned long addr, void *data)
+static int is_mapped_fn(pte_t *pte, unsigned long addr, void *data)
{
return pte_none(*pte) ? 0 : -EBUSY;
}
diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c
index e7df65d32c91..ba883a80b3c0 100644
--- a/drivers/xen/xlate_mmu.c
+++ b/drivers/xen/xlate_mmu.c
@@ -93,8 +93,7 @@ static void setup_hparams(unsigned long gfn, void *data)
info->fgfn++;
}

-static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
- void *data)
+static int remap_pte_fn(pte_t *ptep, unsigned long addr, void *data)
{
struct remap_data *info = data;
struct page *page = info->pages[info->index++];
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 6b10c21630f5..f9509d57edc6 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2595,8 +2595,7 @@ static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)
return 0;
}

-typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
- void *data);
+typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data);
extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
unsigned long size, pte_fn_t fn, void *data);

diff --git a/mm/memory.c b/mm/memory.c
index ab650c21bccd..dd0e64c94ddc 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1952,7 +1952,6 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
{
pte_t *pte;
int err;
- pgtable_t token;
spinlock_t *uninitialized_var(ptl);

pte = (mm == &init_mm) ?
@@ -1965,10 +1964,8 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,

arch_enter_lazy_mmu_mode();

- token = pmd_pgtable(*pmd);
-
do {
- err = fn(pte++, token, addr, data);
+ err = fn(pte++, addr, data);
if (err)
break;
} while (addr += PAGE_SIZE, addr != end);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index e86ba6e74b50..94533beb6b68 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2332,7 +2332,7 @@ void __weak vmalloc_sync_all(void)
}


-static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
+static int f(pte_t *pte, unsigned long addr, void *data)
{
pte_t ***p = data;

--
2.20.1


2019-05-02 13:47:57

by Matthew Wilcox

[permalink] [raw]
Subject: Re: [PATCH] mm/pgtable: Drop pgtable_t variable from pte_fn_t functions

On Thu, May 02, 2019 at 06:48:46PM +0530, Anshuman Khandual wrote:
> Drop the pgtable_t variable from all implementation for pte_fn_t as none of
> them use it. apply_to_pte_range() should stop computing it as well. Should
> help us save some cycles.

You didn't add Martin Schwidefsky for some reason. He introduced
it originally for s390 for sub-page page tables back in 2008 (commit
2f569afd9c). I think he should confirm that he no longer needs it.

> ---
> - Boot tested on arm64 and x86 platforms.
> - Build tested on multiple platforms with their defconfig
>
> arch/arm/kernel/efi.c | 3 +--
> arch/arm/mm/dma-mapping.c | 3 +--
> arch/arm/mm/pageattr.c | 3 +--
> arch/arm64/kernel/efi.c | 3 +--
> arch/arm64/mm/pageattr.c | 3 +--
> arch/x86/xen/mmu_pv.c | 3 +--
> drivers/gpu/drm/i915/i915_mm.c | 3 +--
> drivers/xen/gntdev.c | 6 ++----
> drivers/xen/privcmd.c | 6 ++----
> drivers/xen/xlate_mmu.c | 3 +--
> include/linux/mm.h | 3 +--
> mm/memory.c | 5 +----
> mm/vmalloc.c | 2 +-
> 13 files changed, 15 insertions(+), 31 deletions(-)
>
> diff --git a/arch/arm/kernel/efi.c b/arch/arm/kernel/efi.c
> index 9f43ba012d10..b1f142a01f2f 100644
> --- a/arch/arm/kernel/efi.c
> +++ b/arch/arm/kernel/efi.c
> @@ -11,8 +11,7 @@
> #include <asm/mach/map.h>
> #include <asm/mmu_context.h>
>
> -static int __init set_permissions(pte_t *ptep, pgtable_t token,
> - unsigned long addr, void *data)
> +static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
> {
> efi_memory_desc_t *md = data;
> pte_t pte = *ptep;
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index 43f46aa7ef33..739286511a18 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -496,8 +496,7 @@ void __init dma_contiguous_remap(void)
> }
> }
>
> -static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr,
> - void *data)
> +static int __dma_update_pte(pte_t *pte, unsigned long addr, void *data)
> {
> struct page *page = virt_to_page(addr);
> pgprot_t prot = *(pgprot_t *)data;
> diff --git a/arch/arm/mm/pageattr.c b/arch/arm/mm/pageattr.c
> index 1403cb4a0c3d..c8b500940e1f 100644
> --- a/arch/arm/mm/pageattr.c
> +++ b/arch/arm/mm/pageattr.c
> @@ -22,8 +22,7 @@ struct page_change_data {
> pgprot_t clear_mask;
> };
>
> -static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr,
> - void *data)
> +static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
> {
> struct page_change_data *cdata = data;
> pte_t pte = *ptep;
> diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
> index 4f9acb5fbe97..230cff073a08 100644
> --- a/arch/arm64/kernel/efi.c
> +++ b/arch/arm64/kernel/efi.c
> @@ -86,8 +86,7 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
> return 0;
> }
>
> -static int __init set_permissions(pte_t *ptep, pgtable_t token,
> - unsigned long addr, void *data)
> +static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
> {
> efi_memory_desc_t *md = data;
> pte_t pte = READ_ONCE(*ptep);
> diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
> index 6cd645edcf35..0be077628b21 100644
> --- a/arch/arm64/mm/pageattr.c
> +++ b/arch/arm64/mm/pageattr.c
> @@ -27,8 +27,7 @@ struct page_change_data {
>
> bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED);
>
> -static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr,
> - void *data)
> +static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
> {
> struct page_change_data *cdata = data;
> pte_t pte = READ_ONCE(*ptep);
> diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
> index a21e1734fc1f..308a6195fd26 100644
> --- a/arch/x86/xen/mmu_pv.c
> +++ b/arch/x86/xen/mmu_pv.c
> @@ -2702,8 +2702,7 @@ struct remap_data {
> struct mmu_update *mmu_update;
> };
>
> -static int remap_area_pfn_pte_fn(pte_t *ptep, pgtable_t token,
> - unsigned long addr, void *data)
> +static int remap_area_pfn_pte_fn(pte_t *ptep, unsigned long addr, void *data)
> {
> struct remap_data *rmd = data;
> pte_t pte = pte_mkspecial(mfn_pte(*rmd->pfn, rmd->prot));
> diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c
> index e4935dd1fd37..c23bb29e6d3e 100644
> --- a/drivers/gpu/drm/i915/i915_mm.c
> +++ b/drivers/gpu/drm/i915/i915_mm.c
> @@ -35,8 +35,7 @@ struct remap_pfn {
> pgprot_t prot;
> };
>
> -static int remap_pfn(pte_t *pte, pgtable_t token,
> - unsigned long addr, void *data)
> +static int remap_pfn(pte_t *pte, unsigned long addr, void *data)
> {
> struct remap_pfn *r = data;
>
> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> index 7cf9c51318aa..f0df481e2697 100644
> --- a/drivers/xen/gntdev.c
> +++ b/drivers/xen/gntdev.c
> @@ -264,8 +264,7 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map)
>
> /* ------------------------------------------------------------------ */
>
> -static int find_grant_ptes(pte_t *pte, pgtable_t token,
> - unsigned long addr, void *data)
> +static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data)
> {
> struct gntdev_grant_map *map = data;
> unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
> @@ -292,8 +291,7 @@ static int find_grant_ptes(pte_t *pte, pgtable_t token,
> }
>
> #ifdef CONFIG_X86
> -static int set_grant_ptes_as_special(pte_t *pte, pgtable_t token,
> - unsigned long addr, void *data)
> +static int set_grant_ptes_as_special(pte_t *pte, unsigned long addr, void *data)
> {
> set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte));
> return 0;
> diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
> index b24ddac1604b..4c7268869e2c 100644
> --- a/drivers/xen/privcmd.c
> +++ b/drivers/xen/privcmd.c
> @@ -730,8 +730,7 @@ struct remap_pfn {
> unsigned long i;
> };
>
> -static int remap_pfn_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
> - void *data)
> +static int remap_pfn_fn(pte_t *ptep, unsigned long addr, void *data)
> {
> struct remap_pfn *r = data;
> struct page *page = r->pages[r->i];
> @@ -965,8 +964,7 @@ static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
> * on a per pfn/pte basis. Mapping calls that fail with ENOENT
> * can be then retried until success.
> */
> -static int is_mapped_fn(pte_t *pte, struct page *pmd_page,
> - unsigned long addr, void *data)
> +static int is_mapped_fn(pte_t *pte, unsigned long addr, void *data)
> {
> return pte_none(*pte) ? 0 : -EBUSY;
> }
> diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c
> index e7df65d32c91..ba883a80b3c0 100644
> --- a/drivers/xen/xlate_mmu.c
> +++ b/drivers/xen/xlate_mmu.c
> @@ -93,8 +93,7 @@ static void setup_hparams(unsigned long gfn, void *data)
> info->fgfn++;
> }
>
> -static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
> - void *data)
> +static int remap_pte_fn(pte_t *ptep, unsigned long addr, void *data)
> {
> struct remap_data *info = data;
> struct page *page = info->pages[info->index++];
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 6b10c21630f5..f9509d57edc6 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2595,8 +2595,7 @@ static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)
> return 0;
> }
>
> -typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
> - void *data);
> +typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data);
> extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
> unsigned long size, pte_fn_t fn, void *data);
>
> diff --git a/mm/memory.c b/mm/memory.c
> index ab650c21bccd..dd0e64c94ddc 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1952,7 +1952,6 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
> {
> pte_t *pte;
> int err;
> - pgtable_t token;
> spinlock_t *uninitialized_var(ptl);
>
> pte = (mm == &init_mm) ?
> @@ -1965,10 +1964,8 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
>
> arch_enter_lazy_mmu_mode();
>
> - token = pmd_pgtable(*pmd);
> -
> do {
> - err = fn(pte++, token, addr, data);
> + err = fn(pte++, addr, data);
> if (err)
> break;
> } while (addr += PAGE_SIZE, addr != end);
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index e86ba6e74b50..94533beb6b68 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -2332,7 +2332,7 @@ void __weak vmalloc_sync_all(void)
> }
>
>
> -static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
> +static int f(pte_t *pte, unsigned long addr, void *data)
> {
> pte_t ***p = data;
>
> --
> 2.20.1
>

2019-05-02 14:06:33

by Anshuman Khandual

[permalink] [raw]
Subject: Re: [PATCH] mm/pgtable: Drop pgtable_t variable from pte_fn_t functions



On 05/02/2019 07:16 PM, Matthew Wilcox wrote:
> On Thu, May 02, 2019 at 06:48:46PM +0530, Anshuman Khandual wrote:
>> Drop the pgtable_t variable from all implementation for pte_fn_t as none of
>> them use it. apply_to_pte_range() should stop computing it as well. Should
>> help us save some cycles.
> You didn't add Martin Schwidefsky for some reason. He introduced

scripts/get_maintainer.pl did not list the email but anyways I should have
added it from git blame. Thanks for adding his email to the thread.

2019-05-02 14:16:52

by Martin Schwidefsky

[permalink] [raw]
Subject: Re: [PATCH] mm/pgtable: Drop pgtable_t variable from pte_fn_t functions

On Thu, 2 May 2019 06:46:23 -0700
Matthew Wilcox <[email protected]> wrote:

> On Thu, May 02, 2019 at 06:48:46PM +0530, Anshuman Khandual wrote:
> > Drop the pgtable_t variable from all implementation for pte_fn_t as none of
> > them use it. apply_to_pte_range() should stop computing it as well. Should
> > help us save some cycles.
>
> You didn't add Martin Schwidefsky for some reason. He introduced
> it originally for s390 for sub-page page tables back in 2008 (commit
> 2f569afd9c). I think he should confirm that he no longer needs it.

With its 2K pte tables s390 can not deal with a (struct page *) as a reference
to a page table. But if there are no user of the apply_to_page_range() API
left which actually make use of the token argument we can safely drop it.

> > ---
> > - Boot tested on arm64 and x86 platforms.
> > - Build tested on multiple platforms with their defconfig
> >
> > arch/arm/kernel/efi.c | 3 +--
> > arch/arm/mm/dma-mapping.c | 3 +--
> > arch/arm/mm/pageattr.c | 3 +--
> > arch/arm64/kernel/efi.c | 3 +--
> > arch/arm64/mm/pageattr.c | 3 +--
> > arch/x86/xen/mmu_pv.c | 3 +--
> > drivers/gpu/drm/i915/i915_mm.c | 3 +--
> > drivers/xen/gntdev.c | 6 ++----
> > drivers/xen/privcmd.c | 6 ++----
> > drivers/xen/xlate_mmu.c | 3 +--
> > include/linux/mm.h | 3 +--
> > mm/memory.c | 5 +----
> > mm/vmalloc.c | 2 +-
> > 13 files changed, 15 insertions(+), 31 deletions(-)
> >
> > diff --git a/arch/arm/kernel/efi.c b/arch/arm/kernel/efi.c
> > index 9f43ba012d10..b1f142a01f2f 100644
> > --- a/arch/arm/kernel/efi.c
> > +++ b/arch/arm/kernel/efi.c
> > @@ -11,8 +11,7 @@
> > #include <asm/mach/map.h>
> > #include <asm/mmu_context.h>
> >
> > -static int __init set_permissions(pte_t *ptep, pgtable_t token,
> > - unsigned long addr, void *data)
> > +static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
> > {
> > efi_memory_desc_t *md = data;
> > pte_t pte = *ptep;
> > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> > index 43f46aa7ef33..739286511a18 100644
> > --- a/arch/arm/mm/dma-mapping.c
> > +++ b/arch/arm/mm/dma-mapping.c
> > @@ -496,8 +496,7 @@ void __init dma_contiguous_remap(void)
> > }
> > }
> >
> > -static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr,
> > - void *data)
> > +static int __dma_update_pte(pte_t *pte, unsigned long addr, void *data)
> > {
> > struct page *page = virt_to_page(addr);
> > pgprot_t prot = *(pgprot_t *)data;
> > diff --git a/arch/arm/mm/pageattr.c b/arch/arm/mm/pageattr.c
> > index 1403cb4a0c3d..c8b500940e1f 100644
> > --- a/arch/arm/mm/pageattr.c
> > +++ b/arch/arm/mm/pageattr.c
> > @@ -22,8 +22,7 @@ struct page_change_data {
> > pgprot_t clear_mask;
> > };
> >
> > -static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr,
> > - void *data)
> > +static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
> > {
> > struct page_change_data *cdata = data;
> > pte_t pte = *ptep;
> > diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
> > index 4f9acb5fbe97..230cff073a08 100644
> > --- a/arch/arm64/kernel/efi.c
> > +++ b/arch/arm64/kernel/efi.c
> > @@ -86,8 +86,7 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
> > return 0;
> > }
> >
> > -static int __init set_permissions(pte_t *ptep, pgtable_t token,
> > - unsigned long addr, void *data)
> > +static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
> > {
> > efi_memory_desc_t *md = data;
> > pte_t pte = READ_ONCE(*ptep);
> > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
> > index 6cd645edcf35..0be077628b21 100644
> > --- a/arch/arm64/mm/pageattr.c
> > +++ b/arch/arm64/mm/pageattr.c
> > @@ -27,8 +27,7 @@ struct page_change_data {
> >
> > bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED);
> >
> > -static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr,
> > - void *data)
> > +static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
> > {
> > struct page_change_data *cdata = data;
> > pte_t pte = READ_ONCE(*ptep);
> > diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
> > index a21e1734fc1f..308a6195fd26 100644
> > --- a/arch/x86/xen/mmu_pv.c
> > +++ b/arch/x86/xen/mmu_pv.c
> > @@ -2702,8 +2702,7 @@ struct remap_data {
> > struct mmu_update *mmu_update;
> > };
> >
> > -static int remap_area_pfn_pte_fn(pte_t *ptep, pgtable_t token,
> > - unsigned long addr, void *data)
> > +static int remap_area_pfn_pte_fn(pte_t *ptep, unsigned long addr, void *data)
> > {
> > struct remap_data *rmd = data;
> > pte_t pte = pte_mkspecial(mfn_pte(*rmd->pfn, rmd->prot));
> > diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c
> > index e4935dd1fd37..c23bb29e6d3e 100644
> > --- a/drivers/gpu/drm/i915/i915_mm.c
> > +++ b/drivers/gpu/drm/i915/i915_mm.c
> > @@ -35,8 +35,7 @@ struct remap_pfn {
> > pgprot_t prot;
> > };
> >
> > -static int remap_pfn(pte_t *pte, pgtable_t token,
> > - unsigned long addr, void *data)
> > +static int remap_pfn(pte_t *pte, unsigned long addr, void *data)
> > {
> > struct remap_pfn *r = data;
> >
> > diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> > index 7cf9c51318aa..f0df481e2697 100644
> > --- a/drivers/xen/gntdev.c
> > +++ b/drivers/xen/gntdev.c
> > @@ -264,8 +264,7 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map)
> >
> > /* ------------------------------------------------------------------ */
> >
> > -static int find_grant_ptes(pte_t *pte, pgtable_t token,
> > - unsigned long addr, void *data)
> > +static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data)
> > {
> > struct gntdev_grant_map *map = data;
> > unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
> > @@ -292,8 +291,7 @@ static int find_grant_ptes(pte_t *pte, pgtable_t token,
> > }
> >
> > #ifdef CONFIG_X86
> > -static int set_grant_ptes_as_special(pte_t *pte, pgtable_t token,
> > - unsigned long addr, void *data)
> > +static int set_grant_ptes_as_special(pte_t *pte, unsigned long addr, void *data)
> > {
> > set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte));
> > return 0;
> > diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
> > index b24ddac1604b..4c7268869e2c 100644
> > --- a/drivers/xen/privcmd.c
> > +++ b/drivers/xen/privcmd.c
> > @@ -730,8 +730,7 @@ struct remap_pfn {
> > unsigned long i;
> > };
> >
> > -static int remap_pfn_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
> > - void *data)
> > +static int remap_pfn_fn(pte_t *ptep, unsigned long addr, void *data)
> > {
> > struct remap_pfn *r = data;
> > struct page *page = r->pages[r->i];
> > @@ -965,8 +964,7 @@ static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
> > * on a per pfn/pte basis. Mapping calls that fail with ENOENT
> > * can be then retried until success.
> > */
> > -static int is_mapped_fn(pte_t *pte, struct page *pmd_page,
> > - unsigned long addr, void *data)
> > +static int is_mapped_fn(pte_t *pte, unsigned long addr, void *data)
> > {
> > return pte_none(*pte) ? 0 : -EBUSY;
> > }
> > diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c
> > index e7df65d32c91..ba883a80b3c0 100644
> > --- a/drivers/xen/xlate_mmu.c
> > +++ b/drivers/xen/xlate_mmu.c
> > @@ -93,8 +93,7 @@ static void setup_hparams(unsigned long gfn, void *data)
> > info->fgfn++;
> > }
> >
> > -static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
> > - void *data)
> > +static int remap_pte_fn(pte_t *ptep, unsigned long addr, void *data)
> > {
> > struct remap_data *info = data;
> > struct page *page = info->pages[info->index++];
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index 6b10c21630f5..f9509d57edc6 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -2595,8 +2595,7 @@ static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)
> > return 0;
> > }
> >
> > -typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
> > - void *data);
> > +typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data);
> > extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
> > unsigned long size, pte_fn_t fn, void *data);
> >
> > diff --git a/mm/memory.c b/mm/memory.c
> > index ab650c21bccd..dd0e64c94ddc 100644
> > --- a/mm/memory.c
> > +++ b/mm/memory.c
> > @@ -1952,7 +1952,6 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
> > {
> > pte_t *pte;
> > int err;
> > - pgtable_t token;
> > spinlock_t *uninitialized_var(ptl);
> >
> > pte = (mm == &init_mm) ?
> > @@ -1965,10 +1964,8 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
> >
> > arch_enter_lazy_mmu_mode();
> >
> > - token = pmd_pgtable(*pmd);
> > -
> > do {
> > - err = fn(pte++, token, addr, data);
> > + err = fn(pte++, addr, data);
> > if (err)
> > break;
> > } while (addr += PAGE_SIZE, addr != end);
> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> > index e86ba6e74b50..94533beb6b68 100644
> > --- a/mm/vmalloc.c
> > +++ b/mm/vmalloc.c
> > @@ -2332,7 +2332,7 @@ void __weak vmalloc_sync_all(void)
> > }
> >
> >
> > -static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
> > +static int f(pte_t *pte, unsigned long addr, void *data)
> > {
> > pte_t ***p = data;
> >
> > --
> > 2.20.1
> >
>


--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.

2019-05-03 13:32:10

by Matthew Wilcox

[permalink] [raw]
Subject: Re: [PATCH] mm/pgtable: Drop pgtable_t variable from pte_fn_t functions

On Thu, May 02, 2019 at 04:14:57PM +0200, Martin Schwidefsky wrote:
> On Thu, 2 May 2019 06:46:23 -0700
> Matthew Wilcox <[email protected]> wrote:
>
> > On Thu, May 02, 2019 at 06:48:46PM +0530, Anshuman Khandual wrote:
> > > Drop the pgtable_t variable from all implementation for pte_fn_t as none of
> > > them use it. apply_to_pte_range() should stop computing it as well. Should
> > > help us save some cycles.
> >
> > You didn't add Martin Schwidefsky for some reason. He introduced
> > it originally for s390 for sub-page page tables back in 2008 (commit
> > 2f569afd9c). I think he should confirm that he no longer needs it.
>
> With its 2K pte tables s390 can not deal with a (struct page *) as a reference
> to a page table. But if there are no user of the apply_to_page_range() API
> left which actually make use of the token argument we can safely drop it.

Interestingly, I don't think there ever was a user which used that
argument. Looking at your 2f56 patch, you only converted one function
(presumably there was only one caller of apply_to_page_range() at the
time), and it didn't u se any of the arguments. Xen was the initial user,
and the two other functions they added also didn't use that argument.

Looking at a quick sample of users added since, none of them appear to
have ever used that argument. So removing it seems best.

Acked-by: Matthew Wilcox <[email protected]>