The patch titled Subject: mm: drop support of non-linear mapping from fault codepath has been added to the -mm tree. Its filename is mm-drop-support-of-non-linear-mapping-from-fault-codepath.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-drop-support-of-non-linear-mapping-from-fault-codepath.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-drop-support-of-non-linear-mapping-from-fault-codepath.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Subject: mm: drop support of non-linear mapping from fault codepath 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.shutemov@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mm.h | 16 ++++------ mm/memory.c | 65 +++++-------------------------------------- 2 files changed, 16 insertions(+), 65 deletions(-) diff -puN include/linux/mm.h~mm-drop-support-of-non-linear-mapping-from-fault-codepath include/linux/mm.h --- a/include/linux/mm.h~mm-drop-support-of-non-linear-mapping-from-fault-codepath +++ a/include/linux/mm.h @@ -206,21 +206,19 @@ extern unsigned int kobjsize(const void 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 -puN mm/memory.c~mm-drop-support-of-non-linear-mapping-from-fault-codepath mm/memory.c --- a/mm/memory.c~mm-drop-support-of-non-linear-mapping-from-fault-codepath +++ a/mm/memory.c @@ -1899,12 +1899,11 @@ int apply_to_page_range(struct mm_struct 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, @@ -2710,8 +2709,6 @@ void do_set_pte(struct vm_area_struct *v entry = mk_pte(page, vma->vm_page_prot); if (write) entry = maybe_mkwrite(pte_mkdirty(entry), vma); - else if (pte_file(*pte) && pte_file_soft_dirty(*pte)) - entry = pte_mksoft_dirty(entry); if (anon) { inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); page_add_new_anon_rmap(page, vma, address); @@ -2846,8 +2843,7 @@ static int do_read_fault(struct mm_struc * if page by the offset is not ready to be mapped (cold cache or * something). */ - if (vma->vm_ops->map_pages && !(flags & FAULT_FLAG_NONLINEAR) && - fault_around_bytes >> PAGE_SHIFT > 1) { + if (vma->vm_ops->map_pages && fault_around_bytes >> PAGE_SHIFT > 1) { pte = pte_offset_map_lock(mm, pmd, address, &ptl); do_fault_around(vma, address, pte, pgoff, flags); if (!pte_same(*pte, orig_pte)) @@ -2992,7 +2988,7 @@ static int do_shared_fault(struct mm_str * The mmap_sem may have been released depending on flags and our * return value. See filemap_fault() and __lock_page_or_retry(). */ -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) { @@ -3009,46 +3005,6 @@ static int do_linear_fault(struct mm_str return do_shared_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 pte unmapped and unlocked. - * The mmap_sem may have been released depending on flags and our - * return value. See filemap_fault() and __lock_page_or_retry(). - */ -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); - if (!(flags & FAULT_FLAG_WRITE)) - return do_read_fault(mm, vma, address, pmd, pgoff, flags, - orig_pte); - if (!(vma->vm_flags & VM_SHARED)) - return do_cow_fault(mm, vma, address, pmd, pgoff, flags, - orig_pte); - return do_shared_fault(mm, vma, address, pmd, pgoff, flags, orig_pte); -} - static int numa_migrate_prep(struct page *page, struct vm_area_struct *vma, unsigned long addr, int page_nid, int *flags) @@ -3176,15 +3132,12 @@ static int handle_pte_fault(struct mm_st if (pte_none(entry)) { if (vma->vm_ops) { if (likely(vma->vm_ops->fault)) - return do_linear_fault(mm, vma, address, - pte, pmd, flags, entry); + 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); } _ Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx are mm-protect-set_page_dirty-from-ongoing-truncation.patch mm-replace-remap_file_pages-syscall-with-emulation.patch mm-drop-support-of-non-linear-mapping-from-unmap-zap-codepath.patch mm-drop-support-of-non-linear-mapping-from-fault-codepath.patch mm-drop-vm_ops-remap_pages-and-generic_file_remap_pages-stub.patch proc-drop-handling-non-linear-mappings.patch rmap-drop-support-of-non-linear-mappings.patch mm-replace-vma-shareadlinear-with-vma-shared.patch mm-remove-rest-usage-of-vm_nonlinear-and-pte_file.patch asm-generic-drop-unused-pte_file-helpers.patch alpha-drop-_page_file-and-pte_file-related-helpers.patch arc-drop-_page_file-and-pte_file-related-helpers.patch arm64-drop-pte_file-and-pte_file-related-helpers.patch arm-drop-l_pte_file-and-pte_file-related-helpers.patch avr32-drop-_page_file-and-pte_file-related-helpers.patch blackfin-drop-pte_file.patch c6x-drop-pte_file.patch cris-drop-_page_file-and-pte_file-related-helpers.patch frv-drop-_page_file-and-pte_file-related-helpers.patch hexagon-drop-_page_file-and-pte_file-related-helpers.patch ia64-drop-_page_file-and-pte_file-related-helpers.patch m32r-drop-_page_file-and-pte_file-related-helpers.patch m68k-drop-_page_file-and-pte_file-related-helpers.patch metag-drop-_page_file-and-pte_file-related-helpers.patch microblaze-drop-_page_file-and-pte_file-related-helpers.patch mips-drop-_page_file-and-pte_file-related-helpers.patch mn10300-drop-_page_file-and-pte_file-related-helpers.patch nios2-drop-_page_file-and-pte_file-related-helpers.patch openrisc-drop-_page_file-and-pte_file-related-helpers.patch parisc-drop-_page_file-and-pte_file-related-helpers.patch powerpc-drop-_page_file-and-pte_file-related-helpers.patch s390-drop-pte_file-related-helpers.patch score-drop-_page_file-and-pte_file-related-helpers.patch sh-drop-_page_file-and-pte_file-related-helpers.patch sparc-drop-pte_file-related-helpers.patch tile-drop-pte_file-related-helpers.patch um-drop-_page_file-and-pte_file-related-helpers.patch unicore32-drop-pte_file-related-helpers.patch x86-drop-_page_file-and-pte_file-related-helpers.patch xtensa-drop-_page_file-and-pte_file-related-helpers.patch mm-memory-remove-vm_file-check-on-shared-writable-vmas.patch mm-memory-merge-shared-writable-dirtying-branches-in-do_wp_page.patch mm-add-fields-for-compound-destructor-and-order-into-struct-page.patch mm-add-vm_bug_on_page-for-page_mapcount.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html