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| author |   Matthew Wilcox <mawilcox@microsoft.com> | 2018-06-07 17:08:23 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-07 17:34:37 -0700 |
| commit | 1d40a5ea01d53251c23c7be541d3f4a656cfc537 (patch) | |
| tree | 9c969d32e9baec47e0c0db4592a6a5bfb9a7964c /include | |
| parent | mm: split page_type out from _mapcount (diff) | |
| download | wireguard-linux-1d40a5ea01d53251c23c7be541d3f4a656cfc537.tar.xz wireguard-linux-1d40a5ea01d53251c23c7be541d3f4a656cfc537.zip | |
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')
| -rw-r--r-- | include/linux/mm.h | 2 | ||||
| -rw-r--r-- | include/linux/page-flags.h | 6 | ||||
| -rw-r--r-- | include/uapi/linux/kernel-page-flags.h | 2 |
3 files changed, 9 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index d1dc618a56bf..1dd588b7c649 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1851,6 +1851,7 @@ static inline bool pgtable_page_ctor(struct page *page) { if (!ptlock_init(page)) return false; + __SetPageTable(page); inc_zone_page_state(page, NR_PAGETABLE); return true; } @@ -1858,6 +1859,7 @@ static inline bool pgtable_page_ctor(struct page *page) static inline void pgtable_page_dtor(struct page *page) { pte_lock_deinit(page); + __ClearPageTable(page); dec_zone_page_state(page, NR_PAGETABLE); } 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); diff --git a/include/uapi/linux/kernel-page-flags.h b/include/uapi/linux/kernel-page-flags.h index fa139841ec18..21b9113c69da 100644 --- a/include/uapi/linux/kernel-page-flags.h +++ b/include/uapi/linux/kernel-page-flags.h @@ -35,6 +35,6 @@ #define KPF_BALLOON 23 #define KPF_ZERO_PAGE 24 #define KPF_IDLE 25 - +#define KPF_PGTABLE 26 #endif /* _UAPILINUX_KERNEL_PAGE_FLAGS_H */ |