Re: [PATCH 2/2] mm/page_ref: add tracepoint to track down page reference manipulation
From: Steven Rostedt <hidden>
Date: 2016-02-18 14:29:31
Also in:
linux-mm, lkml
On Mon, 15 Feb 2016 12:04:50 +0900 js1304-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote:
quoted hunk ↗ jump to hunk
diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h index 534249c..fd6d9a5 100644 --- a/include/linux/page_ref.h +++ b/include/linux/page_ref.h@@ -1,6 +1,54 @@ #include <linux/atomic.h> #include <linux/mm_types.h> #include <linux/page-flags.h> +#include <linux/tracepoint-defs.h> + +extern struct tracepoint __tracepoint_page_ref_set; +extern struct tracepoint __tracepoint_page_ref_mod; +extern struct tracepoint __tracepoint_page_ref_mod_and_test; +extern struct tracepoint __tracepoint_page_ref_mod_and_return; +extern struct tracepoint __tracepoint_page_ref_mod_unless; +extern struct tracepoint __tracepoint_page_ref_freeze; +extern struct tracepoint __tracepoint_page_ref_unfreeze; + +#ifdef CONFIG_DEBUG_PAGE_REF
Please add a comment here. Something to the effect of: /* * Ideally we would want to use the trace_<tracepoint>_enabled() helper * functions. But due to include header file issues, that is not * feasible. Instead we have to open code the static key functions. * * See trace_##name##_enabled(void) in include/linux/tracepoint.h */ I may have to work on something that lets these helpers be defined in headers. I have some ideas on how to do that. But for now, this solution is fine. -- Steve
+#define page_ref_tracepoint_active(t) static_key_false(&(t).key)
+
+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_freeze(struct page *page, int v, int ret);
+extern void __page_ref_unfreeze(struct page *page, int v);
+
+#else
+
+#define page_ref_tracepoint_active(t) false
+
+static inline void __page_ref_set(struct page *page, int v)
+{
+}
+static inline void __page_ref_mod(struct page *page, int v)
+{
+}
+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_freeze(struct page *page, int v, int ret)
+{
+}
+static inline void __page_ref_unfreeze(struct page *page, int v)
+{
+}
+
+#endif