mm: Bring sparc pte_index() semantics inline with other platforms.
Subsystems (2)
PATCH 1/1 mm: Bring sparc pte_index() semantics inline with other platforms.
From: Arjun Roy <[email protected]>
pte_index() on platforms other than sparc return a numerical index. On sparc, it returns a pte_t*. This presents an issue for vm_insert_pages(), which relies on pte_index() to find the offset for a pte within a pmd, for batched inserts.
This patch:
1. Modifies pte_index() for sparc to return a numerical index, like other platforms,
2. Defines pte_entry() for sparc which returns a pte_t*
(as pte_index() used to),
3. Converts existing sparc callers for pte_index() to use pte_entry().
--- arch/sparc/include/asm/pgtable_64.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
arch/sparc/include/asm/pgtable_64.h +6 -5
@@ -907,11 +907,12 @@ static inline unsigned long pud_pfn(pud_t pud) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)))/* Find an entry in the third-level page table.. */ -#define pte_index (dir, address) \ - ((pte_t *) __pmd_page(*(dir)) + \ - ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))) -#define pte_offset_kernel pte_index -#define pte_offset_map pte_index +#define pte_index (address) \ + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#define pte_entry (dir, address) \ + ((pte_t *) __pmd_page(*(dir)) + pte_index(address)) +#define pte_offset_kernel pte_entry +#define pte_offset_map pte_entry#define pte_unmap (pte) do { } while (0)/* We cannot include <linux/mm_types.h> at this point yet: */
Signature · 1 line
2.25.0.265.gbab2e86ba0-goog
David -
For full context, this is for a patchset I was working on within MM to reduce spinlock operations for TCP receive zerocopy - which is in and of itself a bit of a complicated situation since it spans mm and net-next - but this change specifically was to fix building on sparc for that patch set.
Stephen (cc'd) suggested that perhaps one route would be to get your ACK for this patch and have it merged into mm, rather than the sparc tree.
For that matter, I'm still curious as to the best process for merging the TCP portion of the patch set - would be happy to hear any ideas you have. I suggested one possibility may be to delay the TCP portion till net-next eventually picks up the rest of the changes, and just change TCP then, but am not sure whether that is the best approach.
Thanks,
-Arjun
Quoted 46 lines · Arjun Roy
From: Arjun Roy <[email protected]>
pte_index()on platforms other than sparc return a numerical index. On sparc, it returns a pte_t*. This presents an issue forvm_insert_pages(), which relies onpte_index()to find the offset for a pte within a pmd, for batched inserts.This patch:
1. Modifiespte_index()for sparc to return a numerical index, like other platforms,
2. Definespte_entry()for sparc which returns a pte_t*
(aspte_index()used to),
3. Converts existing sparc callers forpte_index()to usepte_entry().Signed-off-by Arjun Roy <[email protected]>--- arch/sparc/include/asm/pgtable_64.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)arch/sparc/include/asm/pgtable_64.h +6
-6@@ -907,11 +907,12 @@ static inline unsigned long pud_pfn(pud_t pud) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)))/* Find an entry in the third-level page table.. */ -#define pte_index (dir, address) \ - ((pte_t *) __pmd_page(*(dir)) + \ - ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))) -#define pte_offset_kernel pte_index -#define pte_offset_map pte_index +#define pte_index (address) \ + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#define pte_entry (dir, address) \ + ((pte_t *) __pmd_page(*(dir)) + pte_index(address)) +#define pte_offset_kernel pte_entry +#define pte_offset_map pte_entry#define pte_unmap (pte) do { } while (0)/* We cannot include <linux/mm_types.h> at this point yet: */ --2.25.0.265.gbab2e86ba0-goog
Hi Arjun,
Quoted 8 lines · On Fri, 21 Feb 2020 13:17:07 -0800 Arjun Roy <[email protected]> wrote:
From: Arjun Roy <[email protected]>
pte_index()on platforms other than sparc return a numerical index. On sparc, it returns a pte_t*. This presents an issue forvm_insert_pages(), which relies onpte_index()to find the offset for a pte within a pmd, for batched inserts.
Quoted 5 lines
This patch:
1. Modifiespte_index()for sparc to return a numerical index, like other platforms,
2. Definespte_entry()for sparc which returns a pte_t* (aspte_index()used to),
I wonder if you should not just make pte_offset_kernel() do what the old pte_index() did (this seems to align with what other arches do) and then make pte_offset_map() be defined to be pte_offset_kernel.
arch/sparc/include/asm/pgtable_64.h static inline unsigned long pud_pfn(pud_t pud) · line 915
Quoted 11 lines
arch/sparc/include/asm/pgtable_64.h +6
-5-#define pte_index (dir, address) \ - ((pte_t *) __pmd_page(*(dir)) + \ - ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))) -#define pte_offset_kernel pte_index -#define pte_offset_map pte_index +#define pte_index (address) \ + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#define pte_entry (dir, address) \ + ((pte_t *) __pmd_page(*(dir)) + pte_index(address)) +#define pte_offset_kernel pte_entry +#define pte_offset_map pte_entry
#define pte_offset_kernel(dir, address) \ ((pte_t *) __pmd_page(*(dir)) + pte_index(address))
#define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
Signature · 2 lines
Cheers, Stephen Rothwell
Hi all,
Quoted 45 lines · On Fri, 21 Feb 2020 13:17:07 -0800 Arjun Roy <[email protected]> wrote:
From: Arjun Roy <[email protected]>
pte_index()on platforms other than sparc return a numerical index. On sparc, it returns a pte_t*. This presents an issue forvm_insert_pages(), which relies onpte_index()to find the offset for a pte within a pmd, for batched inserts.This patch:
1. Modifiespte_index()for sparc to return a numerical index, like other platforms,
2. Definespte_entry()for sparc which returns a pte_t*
(aspte_index()used to),
3. Converts existing sparc callers forpte_index()to usepte_entry().Signed-off-by Arjun Roy <[email protected]>--- arch/sparc/include/asm/pgtable_64.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)arch/sparc/include/asm/pgtable_64.h +6
-5@@ -907,11 +907,12 @@ static inline unsigned long pud_pfn(pud_t pud) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)))/* Find an entry in the third-level page table.. */ -#define pte_index (dir, address) \ - ((pte_t *) __pmd_page(*(dir)) + \ - ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))) -#define pte_offset_kernel pte_index -#define pte_offset_map pte_index +#define pte_index (address) \ + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#define pte_entry (dir, address) \ + ((pte_t *) __pmd_page(*(dir)) + pte_index(address)) +#define pte_offset_kernel pte_entry +#define pte_offset_map pte_entry#define pte_unmap (pte) do { } while (0)/* We cannot include <linux/mm_types.h> at this point yet: */ Signature · 1 line
2.25.0.265.gbab2e86ba0-goog
I have applied the following patch to the akpm tree today (just ahead of "mm/memory.c: add vm_insert_pages()") - this includes my suggested changes.
From: Arjun Roy <[email protected]>
Date: Fri, 21 Feb 2020 13:17:07 -0800
Subject: [PATCH] mm: Bring sparc pte_index() semantics inline with other platforms.
pte_index() on platforms other than sparc return a numerical index. On sparc, it returns a pte_t*. This presents an issue for vm_insert_pages(), which relies on pte_index() to find the offset for a pte within a pmd, for batched inserts.
This patch:
1. Modifies pte_index() for sparc to return a numerical index, like other platforms,
2. Defines pte_entry() for sparc which returns a pte_t*
(as pte_index() used to),
3. Converts existing sparc callers for pte_index() to use pte_entry().
sfr: removed pte_entry and just directly modified pte_offset_kernel instead
--- arch/sparc/include/asm/pgtable_64.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
arch/sparc/include/asm/pgtable_64.h +5 -5
@@ -907,11 +907,11 @@ static inline unsigned long pud_pfn(pud_t pud) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)))/* Find an entry in the third-level page table.. */ -#define pte_index (dir, address) \ - ((pte_t *) __pmd_page(*(dir)) + \ - ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))) -#define pte_offset_kernel pte_index -#define pte_offset_map pte_index +#define pte_index (address) \ + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#define pte_offset_kernel (dir, address) \ + ((pte_t *) __pmd_page(*(dir)) + pte_index(address)) +#define pte_offset_map (dir, address) pte_offset_kernel((dir), (address))#define pte_unmap (pte) do { } while (0)/* We cannot include <linux/mm_types.h> at this point yet: */
Signature · 5 lines
2.25.1 -- Cheers, Stephen Rothwell
Quoted 69 lines · Stephen Rothwell
Hi all,
Quoted 45 lines · On Fri, 21 Feb 2020 13:17:07 -0800 Arjun Roy <[email protected]> wrote:
From: Arjun Roy <[email protected]>
pte_index()on platforms other than sparc return a numerical index. On sparc, it returns a pte_t*. This presents an issue forvm_insert_pages(), which relies onpte_index()to find the offset for a pte within a pmd, for batched inserts.This patch:
1. Modifiespte_index()for sparc to return a numerical index, like other platforms,
2. Definespte_entry()for sparc which returns a pte_t*
(aspte_index()used to),
3. Converts existing sparc callers forpte_index()to usepte_entry().Signed-off-by Arjun Roy <[email protected]>--- arch/sparc/include/asm/pgtable_64.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)arch/sparc/include/asm/pgtable_64.h +6
-5@@ -907,11 +907,12 @@ static inline unsigned long pud_pfn(pud_t pud) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)))/* Find an entry in the third-level page table.. */ -#define pte_index (dir, address) \ - ((pte_t *) __pmd_page(*(dir)) + \ - ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))) -#define pte_offset_kernel pte_index -#define pte_offset_map pte_index +#define pte_index (address) \ + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#define pte_entry (dir, address) \ + ((pte_t *) __pmd_page(*(dir)) + pte_index(address)) +#define pte_offset_kernel pte_entry +#define pte_offset_map pte_entry#define pte_unmap (pte) do { } while (0)/* We cannot include <linux/mm_types.h> at this point yet: */ Signature · 1 line
2.25.0.265.gbab2e86ba0-googI have applied the following patch to the akpm tree today (just ahead of "
mm/memory.c: addvm_insert_pages()") - this includes my suggested changes.From: Arjun Roy <[email protected]>
Date: Fri, 21 Feb 2020 13:17:07 -0800
Subject: [PATCH] mm: Bring sparcpte_index()semantics inline with other platforms.
pte_index()on platforms other than sparc return a numerical index. On sparc, it returns a pte_t*. This presents an issue forvm_insert_pages(), which relies onpte_index()to find the offset for a pte within a pmd, for batched inserts.This patch:
1. Modifiespte_index()for sparc to return a numerical index, like other platforms,
2. Definespte_entry()for sparc which returns a pte_t*
(aspte_index()used to),
3. Converts existing sparc callers forpte_index()to usepte_entry().
Quoted 4 lines
sfr: removed
pte_entryand just directly modifiedpte_offset_kernelinsteadSigned-off-by Arjun Roy <[email protected]>Signed-off-by Stephen Rothwell <[email protected]>
FWIW: Reviewed-by: Mike Rapoport <[email protected]>
Quoted 31 lines
--- arch/sparc/include/asm/pgtable_64.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)arch/sparc/include/asm/pgtable_64.h +5
-5@@ -907,11 +907,11 @@ static inline unsigned long pud_pfn(pud_t pud) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)))/* Find an entry in the third-level page table.. */ -#define pte_index (dir, address) \ - ((pte_t *) __pmd_page(*(dir)) + \ - ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))) -#define pte_offset_kernel pte_index -#define pte_offset_map pte_index +#define pte_index (address) \ + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#define pte_offset_kernel (dir, address) \ + ((pte_t *) __pmd_page(*(dir)) + pte_index(address)) +#define pte_offset_map (dir, address) pte_offset_kernel((dir), (address))#define pte_unmap (pte) do { } while (0)/* We cannot include <linux/mm_types.h> at this point yet: */ Signature · 5 lines
2.25.1 -- Cheers, Stephen Rothwell
Signature · 2 lines
Sincerely yours, Mike.