util/ralloc: add total_size helper

It's useful to determine how much memory a nir_shader consumes for debugging
memory bloat, particularly for persistent NIR library. Add a helper that lets us
compute this.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31892>

src/util/ralloc.c

@@ -264,6 +264,31 @@ ralloc_free(void *ptr)
    unsafe_free(info);
 }
 
+#ifndef NDEBUG
+static size_t
+ralloc_total_size_internal(const ralloc_header *info)
+{
+   /* Count the block itself. This requires NDEBUG for the statistic. */
+   unsigned sum = align64(info->size + sizeof(ralloc_header),
+                          alignof(ralloc_header));
+
+   /* Recursively count children */
+   ralloc_header *it = info->child;
+   while (it != NULL) {
+      sum += ralloc_total_size_internal(it);
+      it = it->next;
+   }
+
+   return sum;
+}
+
+size_t
+ralloc_total_size(const void *ptr)
+{
+   return ralloc_total_size_internal(get_header(ptr));
+}
+#endif
+
 static void
 unlink_block(ralloc_header *info)
 {

src/util/ralloc.h

@@ -483,6 +483,16 @@ bool ralloc_asprintf_append (char **str, const char *fmt, ...)
 bool ralloc_vasprintf_append(char **str, const char *fmt, va_list args);
 /// @}
 
+/**
+ * Estimate the memory usage in bytes of a ralloc context, recursively including
+ * all of its child counts. This is only available in debug builds as release
+ * builds do not track size information. It is providing as a aid for debugging
+ * memory bloat.
+ */
+#ifndef NDEBUG
+size_t ralloc_total_size(const void *ptr);
+#endif
+
 typedef struct gc_ctx gc_ctx;
 
 /**