From 08fba69986e20c1c9e5fe2e6064d146cc4f42480 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 6 Jan 2009 14:38:53 -0800 Subject: mm: report the pagesize backing a VMA in /proc/pid/smaps It is useful to verify a hugepage-aware application is using the expected pagesizes for its memory regions. This patch creates an entry called KernelPageSize in /proc/pid/smaps that is the size of page used by the kernel to back a VMA. The entry is not called PageSize as it is possible the MMU uses a different size. This extension should not break any sensible parser that skips lines containing unrecognised information. Signed-off-by: Mel Gorman Acked-by: "KOSAKI Motohiro" Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'mm/hugetlb.c') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 6058b53dcb8..5cb8bc7c80f 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -219,6 +219,22 @@ static pgoff_t vma_hugecache_offset(struct hstate *h, (vma->vm_pgoff >> huge_page_order(h)); } +/* + * Return the size of the pages allocated when backing a VMA. In the majority + * cases this will be same size as used by the page table entries. + */ +unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) +{ + struct hstate *hstate; + + if (!is_vm_hugetlb_page(vma)) + return PAGE_SIZE; + + hstate = hstate_vma(vma); + + return 1UL << (hstate->order + PAGE_SHIFT); +} + /* * Flags for MAP_PRIVATE reservations. These are stored in the bottom * bits of the reservation map pointer, which are always clear due to -- cgit v1.2.3-70-g09d2 From 3340289ddf29ca75c3acfb3a6b72f234b2f74d5c Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 6 Jan 2009 14:38:54 -0800 Subject: 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(-) (limited to 'mm/hugetlb.c') 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 -- cgit v1.2.3-70-g09d2 From ebdd4aea8d736e3b5ce27ab0a26860c9fded341b Mon Sep 17 00:00:00 2001 From: Hannes Eder Date: Tue, 6 Jan 2009 14:39:58 -0800 Subject: hugetlb: fix sparse warnings Fix the following sparse warnings: mm/hugetlb.c:375:3: warning: returning void-valued expression mm/hugetlb.c:408:3: warning: returning void-valued expression Signed-off-by: Hannes Eder Acked-by: Nishanth Aravamudan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'mm/hugetlb.c') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 9595278b5ab..82321da23cc 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -400,8 +400,10 @@ static void clear_huge_page(struct page *page, { int i; - if (unlikely(sz > MAX_ORDER_NR_PAGES)) - return clear_gigantic_page(page, addr, sz); + if (unlikely(sz > MAX_ORDER_NR_PAGES)) { + clear_gigantic_page(page, addr, sz); + return; + } might_sleep(); for (i = 0; i < sz/PAGE_SIZE; i++) { @@ -433,8 +435,10 @@ static void copy_huge_page(struct page *dst, struct page *src, int i; struct hstate *h = hstate_vma(vma); - if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) - return copy_gigantic_page(dst, src, addr, vma); + if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) { + copy_gigantic_page(dst, src, addr, vma); + return; + } might_sleep(); for (i = 0; i < pages_per_huge_page(h); i++) { -- cgit v1.2.3-70-g09d2 From 91f47662dfaa5b459aebe13284c6c38db27350dc Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Tue, 6 Jan 2009 14:40:33 -0800 Subject: mm: hugetlb: remove redundant `if' operation At this point we already know that 'addr' is not NULL so get rid of redundant 'if'. Probably gcc eliminate it by optimization pass. [akpm@linux-foundation.org: use __weak, too] Signed-off-by: Cyrill Gorcunov Reviewed-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'mm/hugetlb.c') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 82321da23cc..618e9830408 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1005,7 +1005,7 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma, return page; } -__attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h) +int __weak alloc_bootmem_huge_page(struct hstate *h) { struct huge_bootmem_page *m; int nr_nodes = nodes_weight(node_online_map); @@ -1024,8 +1024,7 @@ __attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h) * puts them into the mem_map). */ m = addr; - if (m) - goto found; + goto found; } hstate_next_node(h); nr_nodes--; -- cgit v1.2.3-70-g09d2