[Qemu-devel] [PATCH 4/5] trace: Trace qemu_malloc() and qemu_vmalloc()

[Stefan Hajnoczi]

It is often useful to instrument memory management functions in order to
find leaks or performance problems.  This patch adds trace events for
the memory allocation primitives.

Signed-off-by: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com>
---
An example of adding trace events.

 osdep.c       |    9 +++++++++
 qemu-malloc.c |    4 ++++
 trace-events  |   10 ++++++++++
 3 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/osdep.c b/osdep.c
index abbc8a2..8e4b8ea 100644
--- a/osdep.c
+++ b/osdep.c
@@ -50,6 +50,7 @@
 #endif
 
 #include "qemu-common.h"
+#include "trace.h"
 #include "sysemu.h"
 #include "qemu_socket.h"
 
@@ -71,6 +72,8 @@ static void *oom_check(void *ptr)
 #if defined(_WIN32)
 void *qemu_memalign(size_t alignment, size_t size)
 {
+    trace_qemu_memalign(alignment, size);
+
     if (!size) {
         abort();
     }
@@ -79,6 +82,8 @@ void *qemu_memalign(size_t alignment, size_t size)
 
 void *qemu_vmalloc(size_t size)
 {
+    trace_qemu_vmalloc(size);
+
     /* FIXME: this is not exactly optimal solution since VirtualAlloc
        has 64Kb granularity, but at least it guarantees us that the
        memory is page aligned. */
@@ -90,6 +95,7 @@ void *qemu_vmalloc(size_t size)
 
 void qemu_vfree(void *ptr)
 {
+    trace_qemu_vfree(ptr);
     VirtualFree(ptr, 0, MEM_RELEASE);
 }
 
@@ -97,6 +103,8 @@ void qemu_vfree(void *ptr)
 
 void *qemu_memalign(size_t alignment, size_t size)
 {
+    trace_qemu_memalign(alignment, size);
+
 #if defined(_POSIX_C_SOURCE) && !defined(__sun__)
     int ret;
     void *ptr;
@@ -122,6 +130,7 @@ void *qemu_vmalloc(size_t size)
 
 void qemu_vfree(void *ptr)
 {
+    trace_qemu_vfree(ptr);
     free(ptr);
 }
 
diff --git a/qemu-malloc.c b/qemu-malloc.c
index 6cdc5de..69fc3cf 100644
--- a/qemu-malloc.c
+++ b/qemu-malloc.c
@@ -22,6 +22,7 @@
  * THE SOFTWARE.
  */
 #include "qemu-common.h"
+#include "trace.h"
 #include <stdlib.h>
 
 static void *oom_check(void *ptr)
@@ -39,6 +40,7 @@ void *get_mmap_addr(unsigned long size)
 
 void qemu_free(void *ptr)
 {
+    trace_qemu_free(ptr);
     free(ptr);
 }
 
@@ -53,6 +55,7 @@ static int allow_zero_malloc(void)
 
 void *qemu_malloc(size_t size)
 {
+    trace_qemu_malloc(size);
     if (!size && !allow_zero_malloc()) {
         abort();
     }
@@ -61,6 +64,7 @@ void *qemu_malloc(size_t size)
 
 void *qemu_realloc(void *ptr, size_t size)
 {
+    trace_qemu_realloc(ptr, size);
     if (!size && !allow_zero_malloc()) {
         abort();
     }
diff --git a/trace-events b/trace-events
index a37d3cc..a93ea29 100644
--- a/trace-events
+++ b/trace-events
@@ -22,3 +22,13 @@
 # system may not have the necessary headers included.
 #
 # The <format-string> should be a sprintf()-compatible format string.
+
+# qemu-malloc.c
+qemu_malloc(size_t size) "size %zu"
+qemu_realloc(void *ptr, size_t size) "ptr %p size %zu"
+qemu_free(void *ptr) "ptr %p"
+
+# osdep.c
+qemu_memalign(size_t alignment, size_t size) "alignment %zu size %zu"
+qemu_valloc(size_t size) "size %zu"
+qemu_vfree(void *ptr) "ptr %p"
-- 
1.7.1