Add more temporary code to record stack usage at server process exit.

After a look at preliminary results from commit 88cf37d2,
I realized it'd be a good idea to spew out the maximum depth measurement
seen by check_stack_depth.  So add some quick-n-dirty code to do that.
Like the previous commit, this will be reverted once we've gathered
a set of buildfarm runs with it.

src/backend/storage/ipc/ipc.c

@@ -35,6 +35,9 @@
 #include "storage/ipc.h"
 #include "tcop/tcopprot.h"
 
+extern long max_measured_stack_depth;
+extern long max_measured_register_stack_depth;
+
 
 /*
  * This flag is set during proc_exit() to change ereport()'s behavior,
@@ -121,6 +124,15 @@ report_stack_size(void)
 			 (int) getpid());
 	(void) system(sysbuf);
 #endif
+
+#if defined(__ia64__) || defined(__ia64)
+	fprintf(stderr, "max measured stack depths %ldkB, %ldkB\n",
+			(max_measured_stack_depth + 1023) / 1024,
+			(max_measured_register_stack_depth + 1023) / 1024);
+#else
+	fprintf(stderr, "max measured stack depth %ldkB\n",
+			(max_measured_stack_depth + 1023) / 1024);
+#endif
 }
 
 

src/backend/tcop/postgres.c

@@ -96,6 +96,9 @@ int			max_stack_depth = 100;
 /* wait N seconds to allow attach from a debugger */
 int			PostAuthDelay = 0;
 
+/* Exported for use by proc_exit */
+long		max_measured_stack_depth = 0;
+long		max_measured_register_stack_depth = 0;
 
 
 /* ----------------
@@ -3137,6 +3140,11 @@ stack_is_too_deep(void)
 	if (stack_depth < 0)
 		stack_depth = -stack_depth;
 
+	/* Track max measured depth for reporting by proc_exit */
+	if (stack_depth > max_measured_stack_depth &&
+		stack_base_ptr != NULL)
+		max_measured_stack_depth = stack_depth;
+
 	/*
 	 * Trouble?
 	 *
@@ -3160,6 +3168,10 @@ stack_is_too_deep(void)
 #if defined(__ia64__) || defined(__ia64)
 	stack_depth = (long) (ia64_get_bsp() - register_stack_base_ptr);
 
+	if (stack_depth > max_measured_register_stack_depth &&
+		register_stack_base_ptr != NULL)
+		max_measured_register_stack_depth = stack_depth;
+
 	if (stack_depth > max_stack_depth_bytes &&
 		register_stack_base_ptr != NULL)
 		return true;