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 6058b53dcb89..5cb8bc7c80f7 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 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 --- mm/hugetlb.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'mm/hugetlb.c') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 5cb8bc7c80f7..9595278b5ab4 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 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 9595278b5ab4..82321da23cc3 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 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 82321da23cc3..618e98304080 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