Extents: Split out introspection functionality.

This isn't really part of the core extent allocation facilities.  Especially as
this module grows, having it in its own place may come in handy.

include/jemalloc/internal/extent2.h

@@ -17,28 +17,6 @@
  * particular reason.  This will also be changed, but much more immediately.
  */
 
-/*
- * The following two structs are for experimental purposes. See
- * experimental_utilization_query_ctl and
- * experimental_utilization_batch_query_ctl in src/ctl.c.
- */
-typedef struct extent_util_stats_s extent_util_stats_t;
-struct extent_util_stats_s {
-	size_t nfree;
-	size_t nregs;
-	size_t size;
-};
-
-typedef struct extent_util_stats_verbose_s extent_util_stats_verbose_t;
-struct extent_util_stats_verbose_s {
-	void *slabcur_addr;
-	size_t nfree;
-	size_t nregs;
-	size_t size;
-	size_t bin_nfree;
-	size_t bin_nregs;
-};
-
 /*
  * When reuse (and split) an active extent, (1U << opt_lg_extent_max_active_fit)
  * is the max ratio between the size of the active extent and the new extent.
@@ -83,10 +61,4 @@ bool extent_head_no_merge(extent_t *a, extent_t *b);
 
 bool extent_boot(void);
 
-void extent_util_stats_get(tsdn_t *tsdn, const void *ptr,
-    size_t *nfree, size_t *nregs, size_t *size);
-void extent_util_stats_verbose_get(tsdn_t *tsdn, const void *ptr,
-    size_t *nfree, size_t *nregs, size_t *size,
-    size_t *bin_nfree, size_t *bin_nregs, void **slabcur_addr);
-
 #endif /* JEMALLOC_INTERNAL_EXTENT2_H */

include/jemalloc/internal/inspect.h

@@ -0,0 +1,40 @@
+#ifndef JEMALLOC_INTERNAL_INSPECT_H
+#define JEMALLOC_INTERNAL_INSPECT_H
+
+/*
+ * This module contains the heap introspection capabilities.  For now they are
+ * exposed purely through mallctl APIs in the experimental namespace, but this
+ * may change over time.
+ */
+
+/*
+ * The following two structs are for experimental purposes. See
+ * experimental_utilization_query_ctl and
+ * experimental_utilization_batch_query_ctl in src/ctl.c.
+ */
+typedef struct inspect_extent_util_stats_s inspect_extent_util_stats_t;
+struct inspect_extent_util_stats_s {
+	size_t nfree;
+	size_t nregs;
+	size_t size;
+};
+
+typedef struct inspect_extent_util_stats_verbose_s
+    inspect_extent_util_stats_verbose_t;
+
+struct inspect_extent_util_stats_verbose_s {
+	void *slabcur_addr;
+	size_t nfree;
+	size_t nregs;
+	size_t size;
+	size_t bin_nfree;
+	size_t bin_nregs;
+};
+
+void inspect_extent_util_stats_get(tsdn_t *tsdn, const void *ptr,
+    size_t *nfree, size_t *nregs, size_t *size);
+void inspect_extent_util_stats_verbose_get(tsdn_t *tsdn, const void *ptr,
+    size_t *nfree, size_t *nregs, size_t *size,
+    size_t *bin_nfree, size_t *bin_nregs, void **slabcur_addr);
+
+#endif /* JEMALLOC_INTERNAL_INSPECT_H */