Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e1534ae9 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds
Browse files

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: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: default avatarSasha Levin <sasha.levin@oracle.com>
Tested-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: default avatarJerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 53f9263b

arch/arc/mm/cache.c

+2 −2
Original line number Diff line number Diff line
@@ -617,7 +617,7 @@ void flush_dcache_page(struct page *page) 
	 */

	if (!mapping_mapped(mapping)) {

		clear_bit(PG_dc_clean, &page->flags);

	} else if (page_mapped(page)) {

	} else if (page_mapcount(page)) {



		/* kernel reading from page with U-mapping */

		phys_addr_t paddr = (unsigned long)page_address(page);
@@ -857,7 +857,7 @@ void copy_user_highpage(struct page *to, struct page *from, 
	 * For !VIPT cache, all of this gets compiled out as

	 * addr_not_cache_congruent() is 0

	 */

	if (page_mapped(from) && addr_not_cache_congruent(kfrom, u_vaddr)) {

	if (page_mapcount(from) && addr_not_cache_congruent(kfrom, u_vaddr)) {

		__flush_dcache_page((unsigned long)kfrom, u_vaddr);

		clean_src_k_mappings = 1;

	}

arch/arm/mm/flush.c

+1 −1
Original line number Diff line number Diff line
@@ -330,7 +330,7 @@ void flush_dcache_page(struct page *page) 
	mapping = page_mapping(page);



	if (!cache_ops_need_broadcast() &&

	    mapping && !page_mapped(page))

	    mapping && !page_mapcount(page))

		clear_bit(PG_dcache_clean, &page->flags);

	else {

		__flush_dcache_page(mapping, page);

arch/mips/mm/c-r4k.c

+2 −1
Original line number Diff line number Diff line
@@ -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

arch/mips/mm/cache.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

arch/mips/mm/init.c

+3 −3
Original line number Diff line number Diff line
@@ -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();