[RFC v2 2/3] mm: introduce show_page_types() to provide human-readable page_type

[Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>]

Some page flags are not actually set in 'flags' field. To provide
better understanding of tracepoint output, introduce show_page_types()
that shows page flags from page_type.

Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Vasily Averin <vasily.averin@xxxxxxxxx>
Cc: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
---
 include/trace/events/mmflags.h  | 12 ++++++++++++
 include/trace/events/page_ref.h | 10 ++++++++--
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 72c11a16f771..a8dfb98a4dd6 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -136,6 +136,18 @@ IF_HAVE_PG_SKIP_KASAN_POISON(PG_skip_kasan_poison, "skip_kasan_poison")
 	__def_pageflag_names						\
 	) : "none"
 
+#define __def_pagetype_names						\
+	{PG_slab,			"slab"		},		\
+	{PG_offline,			"offline"	},		\
+	{PG_guard,			"guard"		},		\
+	{PG_table,			"table"		},		\
+	{PG_buddy,			"buddy"		}
+
+#define show_page_types(page_type)					\
+	page_type_has_type(page_type) ?					\
+		__print_flags((~page_type), "|", __def_pagetype_names)	\
+	: "none"
+
 #if defined(CONFIG_X86)
 #define __VM_ARCH_SPECIFIC_1 {VM_PAT,     "pat"           }
 #elif defined(CONFIG_PPC)
diff --git a/include/trace/events/page_ref.h b/include/trace/events/page_ref.h
index 8a99c1cd417b..b00d23e90e93 100644
--- a/include/trace/events/page_ref.h
+++ b/include/trace/events/page_ref.h
@@ -21,6 +21,7 @@ DECLARE_EVENT_CLASS(page_ref_mod_template,
 		__field(unsigned long, flags)
 		__field(int, count)
 		__field(int, mapcount)
+		__field(unsigned int, page_type)
 		__field(void *, mapping)
 		__field(int, mt)
 		__field(int, val)
@@ -31,14 +32,16 @@ DECLARE_EVENT_CLASS(page_ref_mod_template,
 		__entry->flags = page->flags;
 		__entry->count = page_ref_count(page);
 		__entry->mapcount = page_mapcount(page);
+		__entry->page_type = page->page_type;
 		__entry->mapping = page->mapping;
 		__entry->mt = get_pageblock_migratetype(page);
 		__entry->val = v;
 	),
 
-	TP_printk("pfn=0x%lx flags=%s count=%d mapcount=%d mapping=%p mt=%d val=%d",
+	TP_printk("pfn=0x%lx flags=%s page_type=%s count=%d mapcount=%d mapping=%p mt=%d val=%d",
 		__entry->pfn,
 		show_page_flags(__entry->flags & PAGEFLAGS_MASK),
+		show_page_types(__entry->page_type & PAGE_TYPE_MASK),
 		__entry->count,
 		__entry->mapcount, __entry->mapping, __entry->mt,
 		__entry->val)
@@ -69,6 +72,7 @@ DECLARE_EVENT_CLASS(page_ref_mod_and_test_template,
 		__field(unsigned long, flags)
 		__field(int, count)
 		__field(int, mapcount)
+		__field(unsigned int, page_type)
 		__field(void *, mapping)
 		__field(int, mt)
 		__field(int, val)
@@ -80,15 +84,17 @@ DECLARE_EVENT_CLASS(page_ref_mod_and_test_template,
 		__entry->flags = page->flags;
 		__entry->count = page_ref_count(page);
 		__entry->mapcount = page_mapcount(page);
+		__entry->page_type = page->page_type;
 		__entry->mapping = page->mapping;
 		__entry->mt = get_pageblock_migratetype(page);
 		__entry->val = v;
 		__entry->ret = ret;
 	),
 
-	TP_printk("pfn=0x%lx flags=%s count=%d mapcount=%d mapping=%p mt=%d val=%d ret=%d",
+	TP_printk("pfn=0x%lx flags=%s page_type=%s count=%d mapcount=%d mapping=%p mt=%d val=%d ret=%d",
 		__entry->pfn,
 		show_page_flags(__entry->flags & PAGEFLAGS_MASK),
+		show_page_types(__entry->page_type & PAGE_TYPE_MASK),
 		__entry->count,
 		__entry->mapcount, __entry->mapping, __entry->mt,
 		__entry->val, __entry->ret)
-- 
2.32.0