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authorMatthew Wilcox <mawilcox@microsoft.com>2018-06-08 03:08:23 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-06-08 03:34:37 +0300
commit1d40a5ea01d53251c23c7be541d3f4a656cfc537 (patch)
tree9c969d32e9baec47e0c0db4592a6a5bfb9a7964c /include/linux/page-flags.h
parent6e292b9be7f4358985ce33ae1f59ab30a8c09e08 (diff)
downloadlinux-1d40a5ea01d53251c23c7be541d3f4a656cfc537.tar.xz
mm: mark pages in use for page tables
Define a new PageTable bit in the page_type and use it to mark pages in use as page tables. This can be helpful when debugging crashdumps or analysing memory fragmentation. Add a KPF flag to report these pages to userspace and update page-types.c to interpret that flag. Note that only pages currently accounted as NR_PAGETABLES are tracked as PageTable; this does not include pgd/p4d/pud/pmd pages. Those will be the subject of a later patch. Link: http://lkml.kernel.org/r/20180518194519.3820-4-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/page-flags.h')
-rw-r--r--include/linux/page-flags.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 8c25b28a35aa..901943e4754b 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -655,6 +655,7 @@ PAGEFLAG_FALSE(DoubleMap)
#define PG_buddy 0x00000080
#define PG_balloon 0x00000100
#define PG_kmemcg 0x00000200
+#define PG_table 0x00000400
#define PageType(page, flag) \
((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
@@ -693,6 +694,11 @@ PAGE_TYPE_OPS(Balloon, balloon)
*/
PAGE_TYPE_OPS(Kmemcg, kmemcg)
+/*
+ * Marks pages in use as page tables.
+ */
+PAGE_TYPE_OPS(Table, table)
+
extern bool is_free_buddy_page(struct page *page);
__PAGEFLAG(Isolated, isolated, PF_ANY);