From e1534ae95004d6a307839a44eed40389d608c935 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 15 Jan 2016 16:53:46 -0800 Subject: mm: differentiate page_mapped() from page_mapcount() for compound pages Let's define page_mapped() to be true for compound pages if any sub-pages of the compound page is mapped (with PMD or PTE). On other hand page_mapcount() return mapcount for this particular small page. This will make cases like page_get_anon_vma() behave correctly once we allow huge pages to be mapped with PTE. Most users outside core-mm should use page_mapcount() instead of page_mapped(). Signed-off-by: Kirill A. Shutemov Tested-by: Sasha Levin Tested-by: Aneesh Kumar K.V Acked-by: Jerome Marchand Cc: Vlastimil Babka Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Dave Hansen Cc: Mel Gorman Cc: Rik van Riel Cc: Naoya Horiguchi Cc: Steve Capper Cc: Johannes Weiner Cc: Michal Hocko Cc: Christoph Lameter Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/mips/mm/c-r4k.c | 3 ++- arch/mips/mm/cache.c | 2 +- arch/mips/mm/init.c | 6 +++--- 3 files changed, 6 insertions(+), 5 deletions(-) (limited to 'arch/mips/mm') diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c index 5d3a25e1cfae..caac3d747a90 100644 --- a/arch/mips/mm/c-r4k.c +++ b/arch/mips/mm/c-r4k.c @@ -587,7 +587,8 @@ static inline void local_r4k_flush_cache_page(void *args) * another ASID than the current one. */ map_coherent = (cpu_has_dc_aliases && - page_mapped(page) && !Page_dcache_dirty(page)); + page_mapcount(page) && + !Page_dcache_dirty(page)); if (map_coherent) vaddr = kmap_coherent(page, addr); else diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c index aab218c36e0d..3f159caf6dbc 100644 --- a/arch/mips/mm/cache.c +++ b/arch/mips/mm/cache.c @@ -106,7 +106,7 @@ void __flush_anon_page(struct page *page, unsigned long vmaddr) unsigned long addr = (unsigned long) page_address(page); if (pages_do_alias(addr, vmaddr)) { - if (page_mapped(page) && !Page_dcache_dirty(page)) { + if (page_mapcount(page) && !Page_dcache_dirty(page)) { void *kaddr; kaddr = kmap_coherent(page, vmaddr); diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index 8770e619185e..7e5fa0938c21 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -165,7 +165,7 @@ void copy_user_highpage(struct page *to, struct page *from, vto = kmap_atomic(to); if (cpu_has_dc_aliases && - page_mapped(from) && !Page_dcache_dirty(from)) { + page_mapcount(from) && !Page_dcache_dirty(from)) { vfrom = kmap_coherent(from, vaddr); copy_page(vto, vfrom); kunmap_coherent(); @@ -187,7 +187,7 @@ void copy_to_user_page(struct vm_area_struct *vma, unsigned long len) { if (cpu_has_dc_aliases && - page_mapped(page) && !Page_dcache_dirty(page)) { + page_mapcount(page) && !Page_dcache_dirty(page)) { void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK); memcpy(vto, src, len); kunmap_coherent(); @@ -205,7 +205,7 @@ void copy_from_user_page(struct vm_area_struct *vma, unsigned long len) { if (cpu_has_dc_aliases && - page_mapped(page) && !Page_dcache_dirty(page)) { + page_mapcount(page) && !Page_dcache_dirty(page)) { void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK); memcpy(dst, vfrom, len); kunmap_coherent(); -- cgit v1.2.3