

Patch from me and "Martin J. Bligh" <mbligh@aracnet.com>

Adds a config option which permits the out-of-line spinlock spinning code to
be moved inline.  So when a kernel is profiled, the cost of the spin appears
in the right function, not in .text.lock.foo.


---

 25-akpm/arch/i386/Kconfig           |    9 ++
 25-akpm/include/asm-i386/rwlock.h   |  135 ++++++++++++++++++++++++------------
 25-akpm/include/asm-i386/spinlock.h |   39 +++++++---
 3 files changed, 128 insertions(+), 55 deletions(-)

diff -puN arch/i386/Kconfig~config_spinline arch/i386/Kconfig
--- 25/arch/i386/Kconfig~config_spinline	Mon May 10 15:30:37 2004
+++ 25-akpm/arch/i386/Kconfig	Mon May 10 15:30:37 2004
@@ -1255,6 +1255,15 @@ config DEBUG_PAGEALLOC
 	  This results in a large slowdown, but helps to find certain types
 	  of memory corruptions.
 
+config SPINLINE
+	bool "Spinlock inlining"
+	depends on DEBUG_KERNEL
+	help
+	  This will change spinlocks from out of line to inline, making them
+	  account cost to the callers in readprofile, rather than the lock
+	  itself (as ".text.lock.filename"). This can be helpful for finding
+	  the callers of locks.
+
 config DEBUG_HIGHMEM
 	bool "Highmem debugging"
 	depends on DEBUG_KERNEL && HIGHMEM
diff -puN include/asm-i386/rwlock.h~config_spinline include/asm-i386/rwlock.h
--- 25/include/asm-i386/rwlock.h~config_spinline	Mon May 10 15:30:37 2004
+++ 25-akpm/include/asm-i386/rwlock.h	Mon May 10 15:30:37 2004
@@ -20,28 +20,52 @@
 #define RW_LOCK_BIAS		 0x01000000
 #define RW_LOCK_BIAS_STR	"0x01000000"
 
-#define __build_read_lock_ptr(rw, helper)   \
-	asm volatile(LOCK "subl $1,(%0)\n\t" \
-		     "js 2f\n" \
-		     "1:\n" \
-		     LOCK_SECTION_START("") \
-		     "2:\tcall " helper "\n\t" \
-		     "jmp 1b\n" \
-		     LOCK_SECTION_END \
-		     ::"a" (rw) : "memory")
-
-#define __build_read_lock_const(rw, helper)   \
-	asm volatile(LOCK "subl $1,%0\n\t" \
-		     "js 2f\n" \
-		     "1:\n" \
-		     LOCK_SECTION_START("") \
-		     "2:\tpushl %%eax\n\t" \
-		     "leal %0,%%eax\n\t" \
-		     "call " helper "\n\t" \
-		     "popl %%eax\n\t" \
-		     "jmp 1b\n" \
-		     LOCK_SECTION_END \
-		     :"=m" (*(volatile int *)rw) : : "memory")
+#ifdef CONFIG_SPINLINE
+
+	#define __build_read_lock_ptr(rw, helper)   \
+		asm volatile(LOCK "subl $1,(%0)\n\t" \
+			     "jns 1f\n\t" \
+			     "call " helper "\n\t" \
+			     "1:\t" \
+			     ::"a" (rw) : "memory")
+
+	#define __build_read_lock_const(rw, helper)   \
+		asm volatile(LOCK "subl $1,%0\n\t" \
+			     "jns 1f\n\t" \
+			     "pushl %%eax\n\t" \
+			     "leal %0,%%eax\n\t" \
+			     "call " helper "\n\t" \
+			     "popl %%eax\n\t" \
+			     "1:\t" \
+			     :"=m" (*(volatile int *)rw) : : "memory")
+
+#else /* !CONFIG_SPINLINE */
+
+	#define __build_read_lock_ptr(rw, helper)   \
+		asm volatile(LOCK "subl $1,(%0)\n\t" \
+			     "js 2f\n" \
+			     "1:\n" \
+			     LOCK_SECTION_START("") \
+			     "2:\tcall " helper "\n\t" \
+			     "jmp 1b\n" \
+			     LOCK_SECTION_END \
+			     ::"a" (rw) : "memory")
+
+	#define __build_read_lock_const(rw, helper)   \
+		asm volatile(LOCK "subl $1,%0\n\t" \
+			     "js 2f\n" \
+			     "1:\n" \
+			     LOCK_SECTION_START("") \
+			     "2:\tpushl %%eax\n\t" \
+			     "leal %0,%%eax\n\t" \
+			     "call " helper "\n\t" \
+			     "popl %%eax\n\t" \
+			     "jmp 1b\n" \
+			     LOCK_SECTION_END \
+			     :"=m" (*(volatile int *)rw) : : "memory")
+
+#endif /* CONFIG_SPINLINE */
+
 
 #define __build_read_lock(rw, helper)	do { \
 						if (__builtin_constant_p(rw)) \
@@ -50,28 +74,51 @@
 							__build_read_lock_ptr(rw, helper); \
 					} while (0)
 
-#define __build_write_lock_ptr(rw, helper) \
-	asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
-		     "jnz 2f\n" \
-		     "1:\n" \
-		     LOCK_SECTION_START("") \
-		     "2:\tcall " helper "\n\t" \
-		     "jmp 1b\n" \
-		     LOCK_SECTION_END \
-		     ::"a" (rw) : "memory")
-
-#define __build_write_lock_const(rw, helper) \
-	asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",%0\n\t" \
-		     "jnz 2f\n" \
-		     "1:\n" \
-		     LOCK_SECTION_START("") \
-		     "2:\tpushl %%eax\n\t" \
-		     "leal %0,%%eax\n\t" \
-		     "call " helper "\n\t" \
-		     "popl %%eax\n\t" \
-		     "jmp 1b\n" \
-		     LOCK_SECTION_END \
-		     :"=m" (*(volatile int *)rw) : : "memory")
+#ifdef CONFIG_SPINLINE
+
+	#define __build_write_lock_ptr(rw, helper) \
+		asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
+			     "jz 1f\n\t" \
+			     "call " helper "\n\t" \
+			     "1:\n" \
+			     ::"a" (rw) : "memory")
+
+	#define __build_write_lock_const(rw, helper) \
+		asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",%0\n\t" \
+			     "jz 1f\n\t" \
+			     "pushl %%eax\n\t" \
+			     "leal %0,%%eax\n\t" \
+			     "call " helper "\n\t" \
+			     "popl %%eax\n\t" \
+			     "1:\n" \
+			     :"=m" (*(volatile int *)rw) : : "memory")
+
+#else /* !CONFIG_SPINLINE */
+
+	#define __build_write_lock_ptr(rw, helper) \
+		asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
+			     "jnz 2f\n" \
+			     "1:\n" \
+			     LOCK_SECTION_START("") \
+			     "2:\tcall " helper "\n\t" \
+			     "jmp 1b\n" \
+			     LOCK_SECTION_END \
+			     ::"a" (rw) : "memory")
+
+	#define __build_write_lock_const(rw, helper) \
+		asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",%0\n\t" \
+			     "jnz 2f\n" \
+			     "1:\n" \
+			     LOCK_SECTION_START("") \
+			     "2:\tpushl %%eax\n\t" \
+			     "leal %0,%%eax\n\t" \
+			     "call " helper "\n\t" \
+			     "popl %%eax\n\t" \
+			     "jmp 1b\n" \
+			     LOCK_SECTION_END \
+			     :"=m" (*(volatile int *)rw) : : "memory")
+
+#endif /* CONFIG_SPINLINE */
 
 #define __build_write_lock(rw, helper)	do { \
 						if (__builtin_constant_p(rw)) \
diff -puN include/asm-i386/spinlock.h~config_spinline include/asm-i386/spinlock.h
--- 25/include/asm-i386/spinlock.h~config_spinline	Mon May 10 15:30:37 2004
+++ 25-akpm/include/asm-i386/spinlock.h	Mon May 10 15:30:37 2004
@@ -44,18 +44,35 @@ typedef struct {
 #define spin_unlock_wait(x)	do { barrier(); } while(spin_is_locked(x))
 #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
 
-#define spin_lock_string \
-	"\n1:\t" \
-	"lock ; decb %0\n\t" \
-	"js 2f\n" \
-	LOCK_SECTION_START("") \
-	"2:\t" \
-	"rep;nop\n\t" \
-	"cmpb $0,%0\n\t" \
-	"jle 2b\n\t" \
-	"jmp 1b\n" \
-	LOCK_SECTION_END
+#ifdef CONFIG_SPINLINE
 
+	#define spin_lock_string \
+		"\n1:\t" \
+		"lock ; decb %0\n\t" \
+		"js 2f\n" \
+		"jmp 3f\n" \
+		"2:\t" \
+		"rep;nop\n\t" \
+		"cmpb $0,%0\n\t" \
+		"jle 2b\n\t" \
+		"jmp 1b\n" \
+		"3:\t"
+
+#else /* !CONFIG_SPINLINE */
+
+	#define spin_lock_string \
+		"\n1:\t" \
+		"lock ; decb %0\n\t" \
+		"js 2f\n" \
+		LOCK_SECTION_START("") \
+		"2:\t" \
+		"rep;nop\n\t" \
+		"cmpb $0,%0\n\t" \
+		"jle 2b\n\t" \
+		"jmp 1b\n" \
+		LOCK_SECTION_END
+
+#endif /* CONFIG_SPINLINE */
 /*
  * This works. Despite all the confusion.
  * (except on PPro SMP or if we are using OOSTORE)

_
