The patch titled
Subject: mm: drop support of non-linear mapping from unmap/zap codepath
has been added to the -mm tree. Its filename is
mm-drop-support-of-non-linear-mapping-from-unmap-zap-codepath.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-drop-support-of-non-linear-mapping-from-unmap-zap-codepath.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-drop-support-of-non-linear-mapping-from-unmap-zap-codepath.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
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------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Subject: mm: drop support of non-linear mapping from unmap/zap codepath
We have remap_file_pages(2) emulation in -mm tree for few release cycles
and we plan to have it mainline in v3.20. This patchset removes rest of
VM_NONLINEAR infrastructure.
Patches 1-8 take care about generic code. They are pretty
straight-forward and can be applied without other of patches.
Rest patches removes pte_file()-related stuff from architecture-specific
code. It usually frees up one bit in non-present pte. I've tried to reuse
that bit for swap offset, where I was able to figure out how to do that.
For obvious reason I cannot test all that arch-specific code and would
like to see acks from maintainers.
In total, remap_file_pages(2) required about 1.4K lines of not-so-trivial
kernel code. That's too much for functionality nobody uses.
Tested-by: Felipe Balbi <balbi@xxxxxx>
This patch (of 38):
We don't create non-linear mappings anymore. Let's drop code which
handles them on unmap/zap.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 1
mm/madvise.c | 9 ----
mm/memory.c | 88 +++++++++++--------------------------------
3 files changed, 25 insertions(+), 73 deletions(-)
diff -puN include/linux/mm.h~mm-drop-support-of-non-linear-mapping-from-unmap-zap-codepath include/linux/mm.h
--- a/include/linux/mm.h~mm-drop-support-of-non-linear-mapping-from-unmap-zap-codepath
+++ a/include/linux/mm.h
@@ -1119,7 +1119,6 @@ extern void user_shm_unlock(size_t, stru
* Parameter block passed down to zap_pte_range in exceptional cases.
*/
struct zap_details {
- struct vm_area_struct *nonlinear_vma; /* Check page->index if set */
struct address_space *check_mapping; /* Check page->mapping if set */
pgoff_t first_index; /* Lowest page->index to unmap */
pgoff_t last_index; /* Highest page->index to unmap */
diff -puN mm/madvise.c~mm-drop-support-of-non-linear-mapping-from-unmap-zap-codepath mm/madvise.c
--- a/mm/madvise.c~mm-drop-support-of-non-linear-mapping-from-unmap-zap-codepath
+++ a/mm/madvise.c
@@ -278,14 +278,7 @@ static long madvise_dontneed(struct vm_a
if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP))
return -EINVAL;
- if (unlikely(vma->vm_flags & VM_NONLINEAR)) {
- struct zap_details details = {
- .nonlinear_vma = vma,
- .last_index = ULONG_MAX,
- };
- zap_page_range(vma, start, end - start, &details);
- } else
- zap_page_range(vma, start, end - start, NULL);
+ zap_page_range(vma, start, end - start, NULL);
return 0;
}
diff -puN mm/memory.c~mm-drop-support-of-non-linear-mapping-from-unmap-zap-codepath mm/memory.c
--- a/mm/memory.c~mm-drop-support-of-non-linear-mapping-from-unmap-zap-codepath
+++ a/mm/memory.c
@@ -1082,6 +1082,7 @@ static unsigned long zap_pte_range(struc
spinlock_t *ptl;
pte_t *start_pte;
pte_t *pte;
+ swp_entry_t entry;
again:
init_rss_vec(rss);
@@ -1107,28 +1108,12 @@ again:
if (details->check_mapping &&
details->check_mapping != page->mapping)
continue;
- /*
- * Each page->index must be checked when
- * invalidating or truncating nonlinear.
- */
- if (details->nonlinear_vma &&
- (page->index < details->first_index ||
- page->index > details->last_index))
- continue;
}
ptent = ptep_get_and_clear_full(mm, addr, pte,
tlb->fullmm);
tlb_remove_tlb_entry(tlb, pte, addr);
if (unlikely(!page))
continue;
- if (unlikely(details) && details->nonlinear_vma
- && linear_page_index(details->nonlinear_vma,
- addr) != page->index) {
- pte_t ptfile = pgoff_to_pte(page->index);
- if (pte_soft_dirty(ptent))
- ptfile = pte_file_mksoft_dirty(ptfile);
- set_pte_at(mm, addr, pte, ptfile);
- }
if (PageAnon(page))
rss[MM_ANONPAGES]--;
else {
@@ -1151,33 +1136,25 @@ again:
}
continue;
}
- /*
- * If details->check_mapping, we leave swap entries;
- * if details->nonlinear_vma, we leave file entries.
- */
+ /* If details->check_mapping, we leave swap entries. */
if (unlikely(details))
continue;
- if (pte_file(ptent)) {
- if (unlikely(!(vma->vm_flags & VM_NONLINEAR)))
- print_bad_pte(vma, addr, ptent, NULL);
- } else {
- swp_entry_t entry = pte_to_swp_entry(ptent);
-
- if (!non_swap_entry(entry))
- rss[MM_SWAPENTS]--;
- else if (is_migration_entry(entry)) {
- struct page *page;
-
- page = migration_entry_to_page(entry);
-
- if (PageAnon(page))
- rss[MM_ANONPAGES]--;
- else
- rss[MM_FILEPAGES]--;
- }
- if (unlikely(!free_swap_and_cache(entry)))
- print_bad_pte(vma, addr, ptent, NULL);
+
+ entry = pte_to_swp_entry(ptent);
+ if (!non_swap_entry(entry))
+ rss[MM_SWAPENTS]--;
+ else if (is_migration_entry(entry)) {
+ struct page *page;
+
+ page = migration_entry_to_page(entry);
+
+ if (PageAnon(page))
+ rss[MM_ANONPAGES]--;
+ else
+ rss[MM_FILEPAGES]--;
}
+ if (unlikely(!free_swap_and_cache(entry)))
+ print_bad_pte(vma, addr, ptent, NULL);
pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);
} while (pte++, addr += PAGE_SIZE, addr != end);
@@ -1277,7 +1254,7 @@ static void unmap_page_range(struct mmu_
pgd_t *pgd;
unsigned long next;
- if (details && !details->check_mapping && !details->nonlinear_vma)
+ if (details && !details->check_mapping)
details = NULL;
BUG_ON(addr >= end);
@@ -1371,7 +1348,7 @@ void unmap_vmas(struct mmu_gather *tlb,
* @vma: vm_area_struct holding the applicable pages
* @start: starting address of pages to zap
* @size: number of bytes to zap
- * @details: details of nonlinear truncation or shared cache invalidation
+ * @details: details of shared cache invalidation
*
* Caller must protect the VMA list
*/
@@ -1397,7 +1374,7 @@ void zap_page_range(struct vm_area_struc
* @vma: vm_area_struct holding the applicable pages
* @address: starting address of pages to zap
* @size: number of bytes to zap
- * @details: details of nonlinear truncation or shared cache invalidation
+ * @details: details of shared cache invalidation
*
* The range must fit into one VMA.
*/
@@ -2331,25 +2308,11 @@ static inline void unmap_mapping_range_t
}
}
-static inline void unmap_mapping_range_list(struct list_head *head,
- struct zap_details *details)
-{
- struct vm_area_struct *vma;
-
- /*
- * In nonlinear VMAs there is no correspondence between virtual address
- * offset and file offset. So we must perform an exhaustive search
- * across *all* the pages in each nonlinear VMA, not just the pages
- * whose virtual address lies outside the file truncation point.
- */
- list_for_each_entry(vma, head, shared.nonlinear) {
- details->nonlinear_vma = vma;
- unmap_mapping_range_vma(vma, vma->vm_start, vma->vm_end, details);
- }
-}
-
/**
- * unmap_mapping_range - unmap the portion of all mmaps in the specified address_space corresponding to the specified page range in the underlying file.
+ * unmap_mapping_range - unmap the portion of all mmaps in the specified
+ * address_space corresponding to the specified page range in the underlying
+ * file.
+ *
* @mapping: the address space containing mmaps to be unmapped.
* @holebegin: byte in first page to unmap, relative to the start of
* the underlying file. This will be rounded down to a PAGE_SIZE
@@ -2378,7 +2341,6 @@ void unmap_mapping_range(struct address_
}
details.check_mapping = even_cows? NULL: mapping;
- details.nonlinear_vma = NULL;
details.first_index = hba;
details.last_index = hba + hlen - 1;
if (details.last_index < details.first_index)
@@ -2388,8 +2350,6 @@ void unmap_mapping_range(struct address_
i_mmap_lock_write(mapping);
if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap)))
unmap_mapping_range_tree(&mapping->i_mmap, &details);
- if (unlikely(!list_empty(&mapping->i_mmap_nonlinear)))
- unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details);
i_mmap_unlock_write(mapping);
}
EXPORT_SYMBOL(unmap_mapping_range);
_
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
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