The patch titled
Subject: mm-thp-handle-page-cache-thp-correctly-in-pagetranscompoundmap-v4
has been removed from the -mm tree. Its filename was
mm-thp-handle-page-cache-thp-correctly-in-pagetranscompoundmap-v4.patch
This patch was dropped because it was folded into mm-thp-handle-page-cache-thp-correctly-in-pagetranscompoundmap.patch
------------------------------------------------------
From: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Subject: mm-thp-handle-page-cache-thp-correctly-in-pagetranscompoundmap-v4
Link: http://lkml.kernel.org/r/1571865575-42913-1-git-send-email-yang.shi@xxxxxxxxxxxxxxxxx
Fixes: dd78fedde4b9 ("rmap: support file thp")
Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Reported-by: Gang Deng <gavin.dg@xxxxxxxxxxxxxxxxx>
Tested-by: Gang Deng <gavin.dg@xxxxxxxxxxxxxxxxx>
Suggested-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 5 --
include/linux/mm_types.h | 5 ++
include/linux/page-flags.h | 70 ++++++++++++++++++-----------------
3 files changed, 42 insertions(+), 38 deletions(-)
--- a/include/linux/mm.h~mm-thp-handle-page-cache-thp-correctly-in-pagetranscompoundmap-v4
+++ a/include/linux/mm.h
@@ -695,11 +695,6 @@ static inline void *kvcalloc(size_t n, s
extern void kvfree(const void *addr);
-static inline atomic_t *compound_mapcount_ptr(struct page *page)
-{
- return &page[1].compound_mapcount;
-}
-
static inline int compound_mapcount(struct page *page)
{
VM_BUG_ON_PAGE(!PageCompound(page), page);
--- a/include/linux/mm_types.h~mm-thp-handle-page-cache-thp-correctly-in-pagetranscompoundmap-v4
+++ a/include/linux/mm_types.h
@@ -221,6 +221,11 @@ struct page {
#endif
} _struct_page_alignment;
+static inline atomic_t *compound_mapcount_ptr(struct page *page)
+{
+ return &page[1].compound_mapcount;
+}
+
/*
* Used for sizing the vmemmap region on some architectures
*/
--- a/include/linux/page-flags.h~mm-thp-handle-page-cache-thp-correctly-in-pagetranscompoundmap-v4
+++ a/include/linux/page-flags.h
@@ -610,6 +610,43 @@ static inline int PageTransCompound(stru
}
/*
+ * PageTransCompoundMap is the same as PageTransCompound, but it also
+ * guarantees the primary MMU has the entire compound page mapped
+ * through pmd_trans_huge, which in turn guarantees the secondary MMUs
+ * can also map the entire compound page. This allows the secondary
+ * MMUs to call get_user_pages() only once for each compound page and
+ * to immediately map the entire compound page with a single secondary
+ * MMU fault. If there will be a pmd split later, the secondary MMUs
+ * will get an update through the MMU notifier invalidation through
+ * split_huge_pmd().
+ *
+ * Unlike PageTransCompound, this is safe to be called only while
+ * split_huge_pmd() cannot run from under us, like if protected by the
+ * MMU notifier, otherwise it may result in page->_mapcount check false
+ * positives.
+ *
+ * We have to treat page cache THP differently since every subpage of it
+ * would get _mapcount inc'ed once it is PMD mapped. But, it may be PTE
+ * mapped in the current process so comparing subpage's _mapcount to
+ * compound_mapcount to filter out PTE mapped case.
+ */
+static inline int PageTransCompoundMap(struct page *page)
+{
+ struct page *head;
+
+ if (!PageTransCompound(page))
+ return 0;
+
+ if (PageAnon(page))
+ return atomic_read(&page->_mapcount) < 0;
+
+ head = compound_head(page);
+ /* File THP is PMD mapped and not PTE mapped */
+ return atomic_read(&page->_mapcount) ==
+ atomic_read(compound_mapcount_ptr(head));
+}
+
+/*
* PageTransTail returns true for both transparent huge pages
* and hugetlbfs pages, so it should only be called when it's known
* that hugetlbfs pages aren't involved.
@@ -660,39 +697,6 @@ static inline int TestClearPageDoubleMap
return test_and_clear_bit(PG_double_map, &page[1].flags);
}
-/*
- * PageTransCompoundMap is the same as PageTransCompound, but it also
- * guarantees the primary MMU has the entire compound page mapped
- * through pmd_trans_huge, which in turn guarantees the secondary MMUs
- * can also map the entire compound page. This allows the secondary
- * MMUs to call get_user_pages() only once for each compound page and
- * to immediately map the entire compound page with a single secondary
- * MMU fault. If there will be a pmd split later, the secondary MMUs
- * will get an update through the MMU notifier invalidation through
- * split_huge_pmd().
- *
- * Unlike PageTransCompound, this is safe to be called only while
- * split_huge_pmd() cannot run from under us, like if protected by the
- * MMU notifier, otherwise it may result in page->_mapcount check false
- * positives.
- *
- * We have to treat page cache THP differently since every subpage of it
- * would get _mapcount inc'ed once it is PMD mapped. But, it may be PTE
- * mapped in the current process so checking PageDoubleMap flag to rule
- * this out.
- */
-static inline int PageTransCompoundMap(struct page *page)
-{
- bool pmd_mapped;
-
- if (PageAnon(page))
- pmd_mapped = atomic_read(&page->_mapcount) < 0;
- else
- pmd_mapped = atomic_read(&page->_mapcount) >= 0 &&
- !PageDoubleMap(compound_head(page));
-
- return PageTransCompound(page) && pmd_mapped;
-}
#else
TESTPAGEFLAG_FALSE(TransHuge)
TESTPAGEFLAG_FALSE(TransCompound)
_
Patches currently in -mm which might be from yang.shi@xxxxxxxxxxxxxxxxx are
mm-thp-handle-page-cache-thp-correctly-in-pagetranscompoundmap.patch
mm-mempolicy-fix-the-wrong-return-value-and-potential-pages-leak-of-mbind.patch
mm-rmap-use-vm_bug_on-in-__page_check_anon_rmap.patch
mm-vmscan-remove-unused-scan_control-parameter-from-pageout.patch
