From: Matthew Wilcox <willy@infradead.org>
To: linux-mm@kvack.org
Cc: "Matthew Wilcox" <mawilcox@microsoft.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
"Christoph Lameter" <cl@linux.com>,
"Lai Jiangshan" <jiangshanlai@gmail.com>,
"Pekka Enberg" <penberg@kernel.org>,
"Vlastimil Babka" <vbabka@suse.cz>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Jérôme Glisse" <jglisse@redhat.com>
Subject: [PATCH v6 03/17] mm: Mark pages in use for page tables
Date: Fri, 18 May 2018 12:45:05 -0700 [thread overview]
Message-ID: <20180518194519.3820-4-willy@infradead.org> (raw)
In-Reply-To: <20180518194519.3820-1-willy@infradead.org>
From: Matthew Wilcox <mawilcox@microsoft.com>
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.
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>
---
fs/proc/page.c | 2 ++
include/linux/mm.h | 2 ++
include/linux/page-flags.h | 6 ++++++
include/uapi/linux/kernel-page-flags.h | 2 +-
tools/vm/page-types.c | 1 +
5 files changed, 12 insertions(+), 1 deletion(-)
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 bd6588479d36..d4e9286a6402 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1819,6 +1819,7 @@ 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;
}
@@ -1826,6 +1827,7 @@ 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",
--
2.17.0
next prev parent reply other threads:[~2018-05-18 19:45 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-18 19:45 [PATCH v6 00/17] Rearrange struct page Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 01/17] s390: Use _refcount for pgtables Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 02/17] mm: Split page_type out from _mapcount Matthew Wilcox
2018-05-18 19:45 ` Matthew Wilcox [this message]
2018-05-18 19:45 ` [PATCH v6 04/17] mm: Switch s_mem and slab_cache in struct page Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 05/17] mm: Move 'private' union within " Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 06/17] mm: Move _refcount out of struct page union Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 07/17] mm: Combine first three unions in struct page Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 08/17] mm: Use page->deferred_list Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 09/17] mm: Move lru union within struct page Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 10/17] mm: Combine LRU and main union in " Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 11/17] mm: Improve struct page documentation Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 12/17] mm: Add pt_mm to struct page Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 13/17] mm: Add hmm_data " Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 14/17] slab,slub: Remove rcu_head size checks Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 15/17] slub: Remove kmem_cache->reserved Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 16/17] slub: Remove 'reserved' file from sysfs Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 17/17] mm: Distinguish VMalloc pages Matthew Wilcox
2018-05-22 16:10 ` Andrey Ryabinin
2018-05-22 17:58 ` Matthew Wilcox
2018-05-22 19:49 ` Andrew Morton
2018-05-22 19:57 ` Andrey Ryabinin
2018-05-22 20:19 ` Matthew Wilcox
2018-05-22 20:48 ` Andrew Morton
2018-05-22 21:45 ` Matthew Wilcox
2018-05-22 23:02 ` Andrew Morton
2018-05-23 6:36 ` Michal Hocko
2018-05-23 6:34 ` Michal Hocko
2018-05-23 9:14 ` Andrey Ryabinin
2018-05-23 9:25 ` Michal Hocko
2018-05-23 9:28 ` Andrey Ryabinin
2018-05-23 9:52 ` Michal Hocko
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