From 3340289ddf29ca75c3acfb3a6b72f234b2f74d5c Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 6 Jan 2009 14:38:54 -0800 Subject: [PATCH] mm: report the MMU pagesize in /proc/pid/smaps The KernelPageSize entry in /proc/pid/smaps is the pagesize used by the kernel to back a VMA. This matches the size used by the MMU in the majority of cases. However, one counter-example occurs on PPC64 kernels whereby a kernel using 64K as a base pagesize may still use 4K pages for the MMU on older processor. To distinguish, this patch reports MMUPageSize as the pagesize used by the MMU in /proc/pid/smaps. Signed-off-by: Mel Gorman Cc: "KOSAKI Motohiro" Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/powerpc/include/asm/hugetlb.h | 6 ++++++ arch/powerpc/mm/hugetlbpage.c | 7 +++++++ fs/proc/task_mmu.c | 6 ++++-- include/linux/hugetlb.h | 3 +++ mm/hugetlb.c | 13 +++++++++++++ 5 files changed, 33 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h index 26f0d0ab27a..b1dafb6a974 100644 --- a/arch/powerpc/include/asm/hugetlb.h +++ b/arch/powerpc/include/asm/hugetlb.h @@ -17,6 +17,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep); +/* + * The version of vma_mmu_pagesize() in arch/powerpc/mm/hugetlbpage.c needs + * to override the version in mm/hugetlb.c + */ +#define vma_mmu_pagesize vma_mmu_pagesize + /* * If the arch doesn't supply something else, assume that hugepage * size aligned regions are ok without further preparation. diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 201c7a5486c..9920d6a7cf2 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -512,6 +512,13 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, return slice_get_unmapped_area(addr, len, flags, mmu_psize, 1, 0); } +unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) +{ + unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start); + + return 1UL << mmu_psize_to_shift(psize); +} + /* * Called by asm hashtable.S for doing lazy icache flush */ diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 41ef5f23e77..94063840832 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -397,7 +397,8 @@ static int show_smap(struct seq_file *m, void *v) "Private_Dirty: %8lu kB\n" "Referenced: %8lu kB\n" "Swap: %8lu kB\n" - "KernelPageSize: %8lu kB\n", + "KernelPageSize: %8lu kB\n" + "MMUPageSize: %8lu kB\n", (vma->vm_end - vma->vm_start) >> 10, mss.resident >> 10, (unsigned long)(mss.pss >> (10 + PSS_SHIFT)), @@ -407,7 +408,8 @@ static int show_smap(struct seq_file *m, void *v) mss.private_dirty >> 10, mss.referenced >> 10, mss.swap >> 10, - vma_kernel_pagesize(vma) >> 10); + vma_kernel_pagesize(vma) >> 10, + vma_mmu_pagesize(vma) >> 10); if (m->count < m->size) /* vma is copied successfully */ m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0; diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 648e1e25979..f1d2fba19ea 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -235,6 +235,8 @@ static inline unsigned long huge_page_size(struct hstate *h) extern unsigned long vma_kernel_pagesize(struct vm_area_struct *vma); +extern unsigned long vma_mmu_pagesize(struct vm_area_struct *vma); + static inline unsigned long huge_page_mask(struct hstate *h) { return h->mask; @@ -276,6 +278,7 @@ struct hstate {}; #define huge_page_size(h) PAGE_SIZE #define huge_page_mask(h) PAGE_MASK #define vma_kernel_pagesize(v) PAGE_SIZE +#define vma_mmu_pagesize(v) PAGE_SIZE #define huge_page_order(h) 0 #define huge_page_shift(h) PAGE_SHIFT static inline unsigned int pages_per_huge_page(struct hstate *h) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 5cb8bc7c80f..9595278b5ab 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -235,6 +235,19 @@ unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) return 1UL << (hstate->order + PAGE_SHIFT); } +/* + * Return the page size being used by the MMU to back a VMA. In the majority + * of cases, the page size used by the kernel matches the MMU size. On + * architectures where it differs, an architecture-specific version of this + * function is required. + */ +#ifndef vma_mmu_pagesize +unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) +{ + return vma_kernel_pagesize(vma); +} +#endif + /* * Flags for MAP_PRIVATE reservations. These are stored in the bottom * bits of the reservation map pointer, which are always clear due to -- 2.41.1