From: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>
We don't create non-linear mappings anymore. Let's drop code which handles them on page fault. Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> https://jira.sw.ru/browse/PSBM-52992 (cherry picked from commit 9b4bdd2ffab9557ac43af7dff02e7dab1c8c58bd) Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> --- include/linux/mm.h | 16 +++++++--------- mm/memory.c | 52 +++++++--------------------------------------------- 2 files changed, 14 insertions(+), 54 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 2acaa83..6d49c59 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -194,21 +194,19 @@ extern unsigned int kobjsize(const void *objp); extern pgprot_t protection_map[16]; #define FAULT_FLAG_WRITE 0x01 /* Fault was a write access */ -#define FAULT_FLAG_NONLINEAR 0x02 /* Fault was via a nonlinear mapping */ -#define FAULT_FLAG_MKWRITE 0x04 /* Fault was mkwrite of existing pte */ -#define FAULT_FLAG_ALLOW_RETRY 0x08 /* Retry fault if blocking */ -#define FAULT_FLAG_RETRY_NOWAIT 0x10 /* Don't drop mmap_sem and wait when retrying */ -#define FAULT_FLAG_KILLABLE 0x20 /* The fault task is in SIGKILL killable region */ -#define FAULT_FLAG_TRIED 0x40 /* second try */ -#define FAULT_FLAG_USER 0x80 /* The fault originated in userspace */ +#define FAULT_FLAG_MKWRITE 0x02 /* Fault was mkwrite of existing pte */ +#define FAULT_FLAG_ALLOW_RETRY 0x04 /* Retry fault if blocking */ +#define FAULT_FLAG_RETRY_NOWAIT 0x08 /* Don't drop mmap_sem and wait when retrying */ +#define FAULT_FLAG_KILLABLE 0x10 /* The fault task is in SIGKILL killable region */ +#define FAULT_FLAG_TRIED 0x20 /* Second try */ +#define FAULT_FLAG_USER 0x40 /* The fault originated in userspace */ /* * vm_fault is filled by the the pagefault handler and passed to the vma's * ->fault function. The vma's ->fault is responsible for returning a bitmask * of VM_FAULT_xxx flags that give details about how the fault was handled. * - * pgoff should be used in favour of virtual_address, if possible. If pgoff - * is used, one may implement ->remap_pages to get nonlinear mapping support. + * pgoff should be used in favour of virtual_address, if possible. */ struct vm_fault { unsigned int flags; /* FAULT_FLAG_xxx flags */ diff --git a/mm/memory.c b/mm/memory.c index 59c8701..e93aa91 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2729,12 +2729,11 @@ int apply_to_page_range(struct mm_struct *mm, unsigned long addr, EXPORT_SYMBOL_GPL(apply_to_page_range); /* - * handle_pte_fault chooses page fault handler according to an entry - * which was read non-atomically. Before making any commitment, on - * those architectures or configurations (e.g. i386 with PAE) which - * might give a mix of unmatched parts, do_swap_page and do_nonlinear_fault - * must check under lock before unmapping the pte and proceeding - * (but do_wp_page is only called after already making such a check; + * handle_pte_fault chooses page fault handler according to an entry which was + * read non-atomically. Before making any commitment, on those architectures + * or configurations (e.g. i386 with PAE) which might give a mix of unmatched + * parts, do_swap_page must check under lock before unmapping the pte and + * proceeding (but do_wp_page is only called after already making such a check; * and do_anonymous_page can safely check later on). */ static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd, @@ -3627,8 +3626,6 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, entry = mk_pte(page, vma->vm_page_prot); if (flags & FAULT_FLAG_WRITE) entry = maybe_mkwrite(pte_mkdirty(entry), vma); - else if (pte_file(orig_pte) && pte_file_soft_dirty(orig_pte)) - entry = pte_mksoft_dirty(entry); if (anon) { inc_mm_counter_fast(mm, MM_ANONPAGES); page_add_new_anon_rmap(page, vma, address); @@ -3694,7 +3691,7 @@ uncharge_out: return ret; } -static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma, +static int do_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *page_table, pmd_t *pmd, unsigned int flags, pte_t orig_pte) { @@ -3708,38 +3705,6 @@ static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma, return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte); } -/* - * Fault of a previously existing named mapping. Repopulate the pte - * from the encoded file_pte if possible. This enables swappable - * nonlinear vmas. - * - * We enter with non-exclusive mmap_sem (to exclude vma changes, - * but allow concurrent faults), and pte mapped but not yet locked. - * We return with mmap_sem still held, but pte unmapped and unlocked. - */ -static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long address, pte_t *page_table, pmd_t *pmd, - unsigned int flags, pte_t orig_pte) -{ - pgoff_t pgoff; - - flags |= FAULT_FLAG_NONLINEAR; - - if (!pte_unmap_same(mm, pmd, page_table, orig_pte)) - return 0; - - if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) { - /* - * Page table corrupted: show pte and kill process. - */ - print_bad_pte(vma, address, orig_pte, NULL); - return VM_FAULT_SIGBUS; - } - - pgoff = pte_to_pgoff(orig_pte); - return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte); -} - int numa_migrate_prep(struct page *page, struct vm_area_struct *vma, unsigned long addr, int page_nid, int *flags) @@ -3854,14 +3819,11 @@ static int handle_pte_fault(struct mm_struct *mm, if (!pte_present(entry)) { if (pte_none(entry)) { if (vma->vm_ops) - return do_linear_fault(mm, vma, address, + return do_fault(mm, vma, address, pte, pmd, flags, entry); return do_anonymous_page(mm, vma, address, pte, pmd, flags); } - if (pte_file(entry)) - return do_nonlinear_fault(mm, vma, address, - pte, pmd, flags, entry); return do_swap_page(mm, vma, address, pte, pmd, flags, entry); } -- 2.7.3 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
