From 54a8eb31f55854ea40e1b07fef86b80b3652e37a Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <schoebel@bell.site>
Date: Fri, 26 Apr 2013 21:05:35 +0200
Subject: [PATCH] infra: add CONFIG_MARS_CHECKS

---
 kernel/Kconfig          | 18 +++++++++++++++++-
 kernel/brick_checking.h | 12 ++++++++++--
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/kernel/Kconfig b/kernel/Kconfig
index 135f5271..0327bc14 100644
--- a/kernel/Kconfig
+++ b/kernel/Kconfig
@@ -9,11 +9,27 @@ config MARS
 	---help---
 	Experimental storage System. Only compile as a module!
 
+config MARS_CHECKS
+	bool "enable simple runtime checks in MARS"
+	depends on MARS
+	default y
+	---help---
+	These checks should be rather lightweight. Use them
+	for beta testing and for production systems where
+	safety is more important than performance.
+	In case of bugs in the reference counting, an automatic	repair
+	is attempted, which lowers the risk of memory corruptions.
+	Disable only if you need the absolutely last grain of
+	performance.
+	If unsure, say Y here.
+
 config MARS_DEBUG
-	bool "enable runtime checks in MARS"
+	bool "enable full runtime checks and some tracing in MARS"
 	depends on MARS
 	default n
 	---help---
+	Some of these checks and some additional error tracing may
+	consume noticable amounts of memory.
 	OFF for production systems. ON for testing!
 
 config MARS_DEBUG_DEFAULT
diff --git a/kernel/brick_checking.h b/kernel/brick_checking.h
index 2ef09117..1014007a 100644
--- a/kernel/brick_checking.h
+++ b/kernel/brick_checking.h
@@ -6,7 +6,7 @@
 
 // checking
 
-#ifdef CONFIG_MARS_DEBUG
+#if defined(CONFIG_MARS_DEBUG) || defined(CONFIG_MARS_CHECKS)
 #define BRICK_CHECKING true
 #else
 #define BRICK_CHECKING false
@@ -16,7 +16,7 @@
 do {									\
 	if (BRICK_CHECKING) {						\
 		int __test = atomic_read(atom);				\
-		if (__test OP (minval)) {				\
+		if (unlikely(__test OP (minval))) {			\
 			atomic_set(atom, minval);			\
 			BRICK_ERR("%d: atomic " #atom " " #OP " " #minval " (%d)\n", __LINE__, __test); \
 		}							\
@@ -34,6 +34,7 @@ do {									\
 	}								\
 } while (0)
 
+#ifdef CONFIG_MARS_DEBUG_MEM
 #define CHECK_PTR_DEAD(ptr,label)					\
 do {									\
 	if (BRICK_CHECKING && unlikely((ptr) == (void*)0x5a5a5a5a5a5a5a5a)) { \
@@ -41,6 +42,9 @@ do {									\
 		goto label;						\
 	}								\
 } while (0)
+#else
+#define CHECK_PTR_DEAD(ptr,label) /*empty*/
+#endif
 
 #define CHECK_PTR_NULL(ptr,label)					\
 do {									\
@@ -51,6 +55,7 @@ do {									\
 	}								\
 } while (0)
 
+#ifdef CONFIG_MARS_DEBUG
 #define CHECK_PTR(ptr,label)						\
 do {									\
 	CHECK_PTR_NULL(ptr, label);					\
@@ -59,6 +64,9 @@ do {									\
 		goto label;						\
 	}								\
 } while (0)
+#else
+#define CHECK_PTR(ptr,label) CHECK_PTR_NULL(ptr,label)
+#endif
 
 #define CHECK_ASPECT(a_ptr, o_ptr,label)				\
   do {								        \