MINOR: debug/memstats: permit to pass the size to free()
Right now the free() call is not intercepted since all this is done
using macros and that would break a lot of stuff. Instead a __free()
macro was provided but never used. In addition it used to only report
a zero size, which is not very convenient.
With this patch comes a better solution. Instead it provides a new
will_free() macro that can be prepended before a call to free(). It
only keeps the counters up to date, and also supports being passed a
size. The pool_free_area() command now uses it, which finally allows
the stats to look correct:
pool-os.h:38 MALLOC size: 5802127832 calls: 3868044 size/call: 1500
pool-os.h:47 FREE size: 5800041576 calls: 3867444 size/call: 1499
The few other places directly calling free() could now be instrumented to
use this and to pass the correct sizeof() when known.
diff --git a/include/haproxy/bug.h b/include/haproxy/bug.h
index f4cc71b..d65c156 100644
--- a/include/haproxy/bug.h
+++ b/include/haproxy/bug.h
@@ -265,11 +265,14 @@
})
/* note: we can't redefine free() because we have a few variables and struct
- * members called like this.
+ * members called like this. This one may be used before a call to free(),
+ * and when known, the size should be indicated, otherwise pass zero. The
+ * pointer is used to know whether the call should be accounted for (null is
+ * ignored).
*/
-#undef __free
-#define __free(x) ({ \
- void *__x = (x); \
+#undef will_free
+#define will_free(x, y) ({ \
+ void *__x = (x); size_t __y = (y); \
static struct mem_stats _ __attribute__((used,__section__("mem_stats"),__aligned__(sizeof(void*)))) = { \
.file = __FILE__, .line = __LINE__, \
.type = MEM_STATS_TYPE_FREE, \
@@ -277,9 +280,10 @@
}; \
HA_WEAK("__start_mem_stats"); \
HA_WEAK("__stop_mem_stats"); \
- if (__x) \
+ if (__x) { \
_HA_ATOMIC_INC(&_.calls); \
- free(__x); \
+ _HA_ATOMIC_ADD(&_.size, __y); \
+ } \
})
#undef ha_free
@@ -345,6 +349,10 @@
_HA_ATOMIC_ADD(&_.size, __y); \
strdup(__x); \
})
+#else // DEBUG_MEM_STATS
+
+#define will_free(x, y) do { } while (0)
+
#endif /* DEBUG_MEM_STATS*/
#endif /* _HAPROXY_BUG_H */
diff --git a/include/haproxy/pool-os.h b/include/haproxy/pool-os.h
index ef3c935..d6612e8 100644
--- a/include/haproxy/pool-os.h
+++ b/include/haproxy/pool-os.h
@@ -44,6 +44,7 @@
*/
static forceinline void pool_free_area(void *area, size_t __maybe_unused size)
{
+ will_free(area, size);
free(area);
}