diff options
| -rw-r--r-- | include/linux/hugetlb.h | 16 | ||||
| -rw-r--r-- | mm/hugetlb.c | 22 | ||||
| -rw-r--r-- | mm/memory.c | 14 |
3 files changed, 27 insertions, 25 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 42cb7d70f9ac..d664330d900e 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -25,6 +25,8 @@ int is_hugepage_mem_enough(size_t); unsigned long hugetlb_total_pages(void); struct page *alloc_huge_page(void); void free_huge_page(struct page *); +int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long address, int write_access); extern unsigned long max_huge_pages; extern const unsigned long hugetlb_zero, hugetlb_infinity; @@ -99,6 +101,7 @@ static inline unsigned long hugetlb_total_pages(void) do { } while (0) #define alloc_huge_page() ({ NULL; }) #define free_huge_page(p) ({ (void)(p); BUG(); }) +#define hugetlb_fault(mm, vma, addr, write) ({ BUG(); 0; }) #ifndef HPAGE_MASK #define HPAGE_MASK 0 /* Keep the compiler happy */ @@ -155,24 +158,11 @@ static inline void set_file_hugepages(struct file *file) { file->f_op = &hugetlbfs_file_operations; } - -static inline int valid_hugetlb_file_off(struct vm_area_struct *vma, - unsigned long address) -{ - struct inode *inode = vma->vm_file->f_dentry->d_inode; - loff_t file_off = address - vma->vm_start; - - file_off += (vma->vm_pgoff << PAGE_SHIFT); - - return (file_off < inode->i_size); -} - #else /* !CONFIG_HUGETLBFS */ #define is_file_hugepages(file) 0 #define set_file_hugepages(file) BUG() #define hugetlb_zero_setup(size) ERR_PTR(-ENOSYS) -#define valid_hugetlb_file_off(vma, address) 0 #endif /* !CONFIG_HUGETLBFS */ diff --git a/mm/hugetlb.c b/mm/hugetlb.c index a1b30d45459e..61d380678030 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -394,6 +394,28 @@ out: return ret; } +/* + * On ia64 at least, it is possible to receive a hugetlb fault from a + * stale zero entry left in the TLB from earlier hardware prefetching. + * Low-level arch code should already have flushed the stale entry as + * part of its fault handling, but we do need to accept this minor fault + * and return successfully. Whereas the "normal" case is that this is + * an access to a hugetlb page which has been truncated off since mmap. + */ +int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long address, int write_access) +{ + int ret = VM_FAULT_SIGBUS; + pte_t *pte; + + spin_lock(&mm->page_table_lock); + pte = huge_pte_offset(mm, address); + if (pte && !pte_none(*pte)) + ret = VM_FAULT_MINOR; + spin_unlock(&mm->page_table_lock); + return ret; +} + int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page **pages, struct vm_area_struct **vmas, unsigned long *position, int *length, int i) diff --git a/mm/memory.c b/mm/memory.c index 8c88b973abc5..1db40e935e55 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2045,18 +2045,8 @@ int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct * vma, inc_page_state(pgfault); - if (unlikely(is_vm_hugetlb_page(vma))) { - if (valid_hugetlb_file_off(vma, address)) - /* We get here only if there was a stale(zero) TLB entry - * (because of HW prefetching). - * Low-level arch code (if needed) should have already - * purged the stale entry as part of this fault handling. - * Here we just return. - */ - return VM_FAULT_MINOR; - else - return VM_FAULT_SIGBUS; /* mapping truncation does this. */ - } + if (unlikely(is_vm_hugetlb_page(vma))) + return hugetlb_fault(mm, vma, address, write_access); /* * We need the page table lock to synchronize with kswapd |