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author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-09 09:39:13 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-09 09:39:13 +0200 |
commit | 10ee08292028d3d22d201a34ba7d24a085818cb3 (patch) | |
tree | cf3bff48a7eab154574355f00a4b4f27dc85ff11 /include/linux/page-flags.h | |
parent | 7da4b8b7378790dd1e4af1bb7522863127fa1438 (diff) | |
parent | 44549e8f5eea4e0a41b487b63e616cb089922b99 (diff) | |
download | linux-stable-10ee08292028d3d22d201a34ba7d24a085818cb3.tar.gz linux-stable-10ee08292028d3d22d201a34ba7d24a085818cb3.tar.bz2 linux-stable-10ee08292028d3d22d201a34ba7d24a085818cb3.zip |
Merge 4.6-rc7 into tty-next
We want the pty fixes in here as well so that patches can build on it.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/page-flags.h')
-rw-r--r-- | include/linux/page-flags.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index f4ed4f1b0c77..6b052aa7b5b7 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -517,6 +517,27 @@ static inline int PageTransCompound(struct page *page) } /* + * 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 < 0 false + * positives. + */ +static inline int PageTransCompoundMap(struct page *page) +{ + return PageTransCompound(page) && atomic_read(&page->_mapcount) < 0; +} + +/* * 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. @@ -559,6 +580,7 @@ static inline int TestClearPageDoubleMap(struct page *page) #else TESTPAGEFLAG_FALSE(TransHuge) TESTPAGEFLAG_FALSE(TransCompound) +TESTPAGEFLAG_FALSE(TransCompoundMap) TESTPAGEFLAG_FALSE(TransTail) TESTPAGEFLAG_FALSE(DoubleMap) TESTSETFLAG_FALSE(DoubleMap) |