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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 | |
| parent | 6e292b9be7f4358985ce33ae1f59ab30a8c09e08 (diff) | |
| download | linux-1d40a5ea01d53251c23c7be541d3f4a656cfc537.tar.gz | |
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>
| -rw-r--r-- | fs/proc/page.c | 2 | ||||
| -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 | ||||
| -rw-r--r-- | tools/vm/page-types.c | 1 |
5 files changed, 12 insertions, 1 deletions
diff --git a/fs/proc/page.c b/fs/proc/page.c index 1491918a33c3..792c78a49174 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -154,6 +154,8 @@ u64 stable_page_flags(struct page *page) if (PageBalloon(page)) u |= 1 << KPF_BALLOON; + if (PageTable(page)) + u |= 1 << KPF_PGTABLE; if (page_is_idle(page)) u |= 1 << KPF_IDLE; 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 */ diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c index a8783f48f77f..cce853dca691 100644 --- a/tools/vm/page-types.c +++ b/tools/vm/page-types.c @@ -131,6 +131,7 @@ static const char * const page_flag_names[] = { [KPF_KSM] = "x:ksm", [KPF_THP] = "t:thp", [KPF_BALLOON] = "o:balloon", + [KPF_PGTABLE] = "g:pgtable", [KPF_ZERO_PAGE] = "z:zero_page", [KPF_IDLE] = "i:idle_page", |