In other page_ref_* functions all arguments and returns are traced, but
in page_ref_add_unless the 'u' argument which stands for unless boolean
is not traced. However, what is more confusing is that in the tracing
routine:
__page_ref_mod_unless(struct page *page, int v, int u);
The 'u' argument present, but instead a return value is passed into
this argument.
Add a new template specific for page_ref_add_unless(), and trace all
arguments and the return value.
Fixes: 95813b8faa0c ("mm/page_ref: add tracepoint to track down page reference manipulation")
Signed-off-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
---
include/linux/page_ref.h | 10 ++++----
include/trace/events/page_ref.h | 43 ++++++++++++++++++++++++++++++---
mm/debug_page_ref.c | 8 +++---
3 files changed, 49 insertions(+), 12 deletions(-)
diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h
index 2e677e6ad09f..1903af5fb087 100644
--- a/include/linux/page_ref.h
+++ b/include/linux/page_ref.h
@@ -11,7 +11,7 @@ DECLARE_TRACEPOINT(page_ref_set);
DECLARE_TRACEPOINT(page_ref_mod);
DECLARE_TRACEPOINT(page_ref_mod_and_test);
DECLARE_TRACEPOINT(page_ref_mod_and_return);
-DECLARE_TRACEPOINT(page_ref_mod_unless);
+DECLARE_TRACEPOINT(page_ref_add_unless);
DECLARE_TRACEPOINT(page_ref_freeze);
DECLARE_TRACEPOINT(page_ref_unfreeze);
@@ -30,7 +30,7 @@ extern void __page_ref_set(struct page *page, int v);
extern void __page_ref_mod(struct page *page, int v);
extern void __page_ref_mod_and_test(struct page *page, int v, int ret);
extern void __page_ref_mod_and_return(struct page *page, int v, int ret);
-extern void __page_ref_mod_unless(struct page *page, int v, int u);
+extern void __page_ref_add_unless(struct page *page, int v, int u, int ret);
extern void __page_ref_freeze(struct page *page, int v, int ret);
extern void __page_ref_unfreeze(struct page *page, int v);
@@ -50,7 +50,7 @@ static inline void __page_ref_mod_and_test(struct page *page, int v, int ret)
static inline void __page_ref_mod_and_return(struct page *page, int v, int ret)
{
}
-static inline void __page_ref_mod_unless(struct page *page, int v, int u)
+static inline void __page_ref_add_unless(struct page *page, int v, int u, int ret)
{
}
static inline void __page_ref_freeze(struct page *page, int v, int ret)
@@ -237,8 +237,8 @@ static inline bool page_ref_add_unless(struct page *page, int nr, int u)
{
bool ret = atomic_add_unless(&page->_refcount, nr, u);
- if (page_ref_tracepoint_active(page_ref_mod_unless))
- __page_ref_mod_unless(page, nr, ret);
+ if (page_ref_tracepoint_active(page_ref_add_unless))
+ __page_ref_add_unless(page, nr, u, ret);
return ret;
}
diff --git a/include/trace/events/page_ref.h b/include/trace/events/page_ref.h
index 8a99c1cd417b..c32d6d161cdb 100644
--- a/include/trace/events/page_ref.h
+++ b/include/trace/events/page_ref.h
@@ -94,6 +94,43 @@ DECLARE_EVENT_CLASS(page_ref_mod_and_test_template,
__entry->val, __entry->ret)
);
+DECLARE_EVENT_CLASS(page_ref_add_unless_template,
+
+ TP_PROTO(struct page *page, int v, int u, int ret),
+
+ TP_ARGS(page, v, u, ret),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, pfn)
+ __field(unsigned long, flags)
+ __field(int, count)
+ __field(int, mapcount)
+ __field(void *, mapping)
+ __field(int, mt)
+ __field(int, val)
+ __field(int, unless)
+ __field(int, ret)
+ ),
+
+ TP_fast_assign(
+ __entry->pfn = page_to_pfn(page);
+ __entry->flags = page->flags;
+ __entry->count = page_ref_count(page);
+ __entry->mapcount = page_mapcount(page);
+ __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 unless=%d ret=%d",
+ __entry->pfn,
+ show_page_flags(__entry->flags & PAGEFLAGS_MASK),
+ __entry->count,
+ __entry->mapcount, __entry->mapping, __entry->mt,
+ __entry->val, __entry->unless, __entry->ret)
+);
+
DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_mod_and_test,
TP_PROTO(struct page *page, int v, int ret),
@@ -108,11 +145,11 @@ DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_mod_and_return,
TP_ARGS(page, v, ret)
);
-DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_mod_unless,
+DEFINE_EVENT(page_ref_add_unless_template, page_ref_add_unless,
- TP_PROTO(struct page *page, int v, int ret),
+ TP_PROTO(struct page *page, int v, int u, int ret),
- TP_ARGS(page, v, ret)
+ TP_ARGS(page, v, u, ret)
);
DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_freeze,
diff --git a/mm/debug_page_ref.c b/mm/debug_page_ref.c
index f3b2c9d3ece2..1426d6887b01 100644
--- a/mm/debug_page_ref.c
+++ b/mm/debug_page_ref.c
@@ -33,12 +33,12 @@ void __page_ref_mod_and_return(struct page *page, int v, int ret)
EXPORT_SYMBOL(__page_ref_mod_and_return);
EXPORT_TRACEPOINT_SYMBOL(page_ref_mod_and_return);
-void __page_ref_mod_unless(struct page *page, int v, int u)
+void __page_ref_add_unless(struct page *page, int v, int u, int ret)
{
- trace_page_ref_mod_unless(page, v, u);
+ trace_page_ref_add_unless(page, v, u, ret);
}
-EXPORT_SYMBOL(__page_ref_mod_unless);
-EXPORT_TRACEPOINT_SYMBOL(page_ref_mod_unless);
+EXPORT_SYMBOL(__page_ref_add_unless);
+EXPORT_TRACEPOINT_SYMBOL(page_ref_add_unless);
void __page_ref_freeze(struct page *page, int v, int ret)
{
--
2.34.1.400.ga245620fadb-goog
