[PATCH] mm: cma: add trace events for CMA allocations and freeings

* [PATCH] mm: cma: add trace events for CMA allocations and freeings
@ 2015-04-01 13:31 Stefan Strogin
  2015-04-02  7:33 ` Joonsoo Kim
  0 siblings, 1 reply; 4+ messages in thread
From: Stefan Strogin @ 2015-04-01 13:31 UTC (permalink / raw)
  To: linux-mm, linux-kernel
  Cc: Stefan Strogin, Steven Rostedt, Ingo Molnar, Joonsoo Kim,
	Andrew Morton, Marek Szyprowski, Michal Nazarewicz, aneesh.kumar,
	Laurent Pinchart, Sasha Levin, Dmitry Safonov, Pintu Kumar,
	Laura Abbott, Dyasly Sergey, Vyacheslav Tyrtov,
	Aleksei Mateosian, gioh.kim, stefan.strogin

Add trace events for cma_alloc() and cma_release().

The cma_alloc tracepoint is used both for successful and failed allocations,
in case of allocation failure pfn=-1UL is stored and printed.

Signed-off-by: Stefan Strogin <stefan.strogin@gmail.com>
---

Took out from the patch set "mm: cma: add some debug information for CMA" v4
(http://thread.gmane.org/gmane.linux.kernel.mm/129903) because of probable
uselessness of the rest of the patches.

Changes from the version from the patch set:
- Constify the struct page * parameter passed to the tracepoints.
- Pass both pfn and struct page * to the tracepoints to decrease unnecessary
  pfn_to_page() and page_to_pfn() calls and avoid using them in TP_printk.
- Store and print pfn=-1UL instead of pfn=0, because 0th pfn can truly exist
  on some architectures.

 include/trace/events/cma.h | 63 ++++++++++++++++++++++++++++++++++++++++++++++
 mm/cma.c                   |  5 ++++
 2 files changed, 68 insertions(+)
 create mode 100644 include/trace/events/cma.h

diff --git a/include/trace/events/cma.h b/include/trace/events/cma.h
new file mode 100644
index 0000000..e01b35d
--- /dev/null
+++ b/include/trace/events/cma.h
@@ -0,0 +1,63 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM cma
+
+#if !defined(_TRACE_CMA_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_CMA_H
+
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(cma_alloc,
+
+	TP_PROTO(unsigned long pfn, const struct page *page,
+		 unsigned int count),
+
+	TP_ARGS(pfn, page, count),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, pfn)
+		__field(const struct page *, page)
+		__field(unsigned int, count)
+	),
+
+	TP_fast_assign(
+		__entry->pfn = pfn;
+		__entry->page = page;
+		__entry->count = count;
+	),
+
+	TP_printk("pfn=%lx page=%p count=%u",
+		  __entry->pfn,
+		  __entry->page,
+		  __entry->count)
+);
+
+TRACE_EVENT(cma_release,
+
+	TP_PROTO(unsigned long pfn, const struct page *page,
+		 unsigned int count),
+
+	TP_ARGS(pfn, page, count),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, pfn)
+		__field(const struct page *, page)
+		__field(unsigned int, count)
+	),
+
+	TP_fast_assign(
+		__entry->pfn = pfn;
+		__entry->page = page;
+		__entry->count = count;
+	),
+
+	TP_printk("pfn=%lx page=%p count=%u",
+		  __entry->pfn,
+		  __entry->page,
+		  __entry->count)
+);
+
+#endif /* _TRACE_CMA_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/mm/cma.c b/mm/cma.c
index 47203fa..e9410b7c 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -23,6 +23,7 @@
 #  define DEBUG
 #endif
 #endif
+#define CREATE_TRACE_POINTS
 
 #include <linux/memblock.h>
 #include <linux/err.h>
@@ -34,6 +35,7 @@
 #include <linux/cma.h>
 #include <linux/highmem.h>
 #include <linux/io.h>
+#include <trace/events/cma.h>
 
 #include "cma.h"
 
@@ -414,6 +416,8 @@ struct page *cma_alloc(struct cma *cma, unsigned int count, unsigned int align)
 		start = bitmap_no + mask + 1;
 	}
 
+	trace_cma_alloc(page ? pfn : -1UL, page, count);
+
 	pr_debug("%s(): returned %p\n", __func__, page);
 	return page;
 }
@@ -446,6 +450,7 @@ bool cma_release(struct cma *cma, const struct page *pages, unsigned int count)
 
 	free_contig_range(pfn, count);
 	cma_clear_bitmap(cma, pfn, count);
+	trace_cma_release(pfn, pages, count);
 
 	return true;
 }
-- 
2.1.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread