From 092b50bacd1cdbffef2643b7a46f2a215407919c Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Wed, 21 Mar 2012 16:33:59 -0700 Subject: [PATCH] pagemap: introduce data structure for pagemap entry Currently a local variable of pagemap entry in pagemap_pte_range() is named pfn and typed with u64, but it's not correct (pfn should be unsigned long.) This patch introduces special type for pagemap entries and replaces code with it. Signed-off-by: Naoya Horiguchi Cc: David Rientjes Cc: Andi Kleen Cc: Wu Fengguang Cc: Andrea Arcangeli Cc: KOSAKI Motohiro Reviewed-by: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/task_mmu.c | 69 +++++++++++++++++++++++++++++----------------------- 1 file changed, 38 insertions(+), 31 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 328843d..c7e3a16 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -594,9 +594,13 @@ const struct file_operations proc_clear_refs_operations = { .llseek = noop_llseek, }; +typedef struct { + u64 pme; +} pagemap_entry_t; + struct pagemapread { int pos, len; - u64 *buffer; + pagemap_entry_t *buffer; }; #define PAGEMAP_WALK_SIZE (PMD_SIZE) @@ -619,10 +623,15 @@ struct pagemapread { #define PM_NOT_PRESENT PM_PSHIFT(PAGE_SHIFT) #define PM_END_OF_BUFFER 1 -static int add_to_pagemap(unsigned long addr, u64 pfn, +static inline pagemap_entry_t make_pme(u64 val) +{ + return (pagemap_entry_t) { .pme = val }; +} + +static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme, struct pagemapread *pm) { - pm->buffer[pm->pos++] = pfn; + pm->buffer[pm->pos++] = *pme; if (pm->pos >= pm->len) return PM_END_OF_BUFFER; return 0; @@ -634,8 +643,10 @@ static int pagemap_pte_hole(unsigned long start, unsigned long end, struct pagemapread *pm = walk->private; unsigned long addr; int err = 0; + pagemap_entry_t pme = make_pme(PM_NOT_PRESENT); + for (addr = start; addr < end; addr += PAGE_SIZE) { - err = add_to_pagemap(addr, PM_NOT_PRESENT, pm); + err = add_to_pagemap(addr, &pme, pm); if (err) break; } @@ -648,36 +659,33 @@ static u64 swap_pte_to_pagemap_entry(pte_t pte) return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT); } -static u64 pte_to_pagemap_entry(pte_t pte) +static void pte_to_pagemap_entry(pagemap_entry_t *pme, pte_t pte) { - u64 pme = 0; if (is_swap_pte(pte)) - pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte)) - | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP; + *pme = make_pme(PM_PFRAME(swap_pte_to_pagemap_entry(pte)) + | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP); else if (pte_present(pte)) - pme = PM_PFRAME(pte_pfn(pte)) - | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; - return pme; + *pme = make_pme(PM_PFRAME(pte_pfn(pte)) + | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE -static u64 thp_pmd_to_pagemap_entry(pmd_t pmd, int offset) +static void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, + pmd_t pmd, int offset) { - u64 pme = 0; /* * Currently pmd for thp is always present because thp can not be * swapped-out, migrated, or HWPOISONed (split in such cases instead.) * This if-check is just to prepare for future implementation. */ if (pmd_present(pmd)) - pme = PM_PFRAME(pmd_pfn(pmd) + offset) - | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; - return pme; + *pme = make_pme(PM_PFRAME(pmd_pfn(pmd) + offset) + | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT); } #else -static inline u64 thp_pmd_to_pagemap_entry(pmd_t pmd, int offset) +static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, + pmd_t pmd, int offset) { - return 0; } #endif @@ -688,7 +696,7 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct pagemapread *pm = walk->private; pte_t *pte; int err = 0; - u64 pfn = PM_NOT_PRESENT; + pagemap_entry_t pme = make_pme(PM_NOT_PRESENT); if (pmd_trans_unstable(pmd)) return 0; @@ -702,8 +710,8 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, offset = (addr & ~PAGEMAP_WALK_MASK) >> PAGE_SHIFT; - pfn = thp_pmd_to_pagemap_entry(*pmd, offset); - err = add_to_pagemap(addr, pfn, pm); + thp_pmd_to_pagemap_entry(&pme, *pmd, offset); + err = add_to_pagemap(addr, &pme, pm); if (err) break; } @@ -723,11 +731,11 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, if (vma && (vma->vm_start <= addr) && !is_vm_hugetlb_page(vma)) { pte = pte_offset_map(pmd, addr); - pfn = pte_to_pagemap_entry(*pte); + pte_to_pagemap_entry(&pme, *pte); /* unmap before userspace copy */ pte_unmap(pte); } - err = add_to_pagemap(addr, pfn, pm); + err = add_to_pagemap(addr, &pme, pm); if (err) return err; } @@ -738,13 +746,12 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, } #ifdef CONFIG_HUGETLB_PAGE -static u64 huge_pte_to_pagemap_entry(pte_t pte, int offset) +static void huge_pte_to_pagemap_entry(pagemap_entry_t *pme, + pte_t pte, int offset) { - u64 pme = 0; if (pte_present(pte)) - pme = PM_PFRAME(pte_pfn(pte) + offset) - | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT; - return pme; + *pme = make_pme(PM_PFRAME(pte_pfn(pte) + offset) + | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT); } /* This function walks within one hugetlb entry in the single call */ @@ -754,12 +761,12 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask, { struct pagemapread *pm = walk->private; int err = 0; - u64 pfn; + pagemap_entry_t pme = make_pme(PM_NOT_PRESENT); for (; addr != end; addr += PAGE_SIZE) { int offset = (addr & ~hmask) >> PAGE_SHIFT; - pfn = huge_pte_to_pagemap_entry(*pte, offset); - err = add_to_pagemap(addr, pfn, pm); + huge_pte_to_pagemap_entry(&pme, *pte, offset); + err = add_to_pagemap(addr, &pme, pm); if (err) return err; } -- 1.7.10.4