Thread (6 messages) 6 messages, 2 authors, 2009-03-04

[patch 2/2] powerpc: replace isync with lwsync

STALE6424d

From: Nick Piggin <hidden>
Date: 2009-02-19 17:21:40 

OK, here is this patch again. You didn't think I'd let a 2% performance
improvement be forgotten? :)

Anyway, patch won't work well on architecture without lwsync, but I won't
bother fixing that kind of thing and making it merge worthy until you
guys say something positive about it.

20 runs of tbench on the G5

unpatched AVG=920.37 STD=2.36
  patched AVG=938.89 STD=3.33

(throughput in MB/s) This is a 1.9% throughput increase.

---

Index: linux-2.6/arch/powerpc/include/asm/atomic.h
===================================================================
--- linux-2.6.orig/arch/powerpc/include/asm/atomic.h	2009-02-20 01:50:20.000000000 +1100
+++ linux-2.6/arch/powerpc/include/asm/atomic.h	2009-02-20 02:13:22.000000000 +1100
@@ -55,7 +55,7 @@
 	PPC405_ERR77(0,%2)
 "	stwcx.	%0,0,%2 \n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (t)
 	: "r" (a), "r" (&v->counter)
 	: "cc", "memory");
@@ -91,7 +91,7 @@
 	PPC405_ERR77(0,%2)
 "	stwcx.	%0,0,%2 \n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (t)
 	: "r" (a), "r" (&v->counter)
 	: "cc", "memory");
@@ -125,7 +125,7 @@
 	PPC405_ERR77(0,%1)
 "	stwcx.	%0,0,%1 \n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (t)
 	: "r" (&v->counter)
 	: "cc", "xer", "memory");
@@ -169,7 +169,7 @@
 	PPC405_ERR77(0,%1)
 "	stwcx.	%0,0,%1\n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (t)
 	: "r" (&v->counter)
 	: "cc", "xer", "memory");
@@ -202,7 +202,7 @@
 	PPC405_ERR77(0,%2)
 "	stwcx.	%0,0,%1 \n\
 	bne-	1b \n"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 "	subf	%0,%2,%0 \n\
 2:"
 	: "=&r" (t)
@@ -235,7 +235,7 @@
 	PPC405_ERR77(0,%1)
 "	stwcx.	%0,0,%1\n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	"\n\
 2:"	: "=&b" (t)
 	: "r" (&v->counter)
@@ -291,7 +291,7 @@
 	add	%0,%1,%0\n\
 	stdcx.	%0,0,%2 \n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (t)
 	: "r" (a), "r" (&v->counter)
 	: "cc", "memory");
@@ -325,7 +325,7 @@
 	subf	%0,%1,%0\n\
 	stdcx.	%0,0,%2 \n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (t)
 	: "r" (a), "r" (&v->counter)
 	: "cc", "memory");
@@ -357,7 +357,7 @@
 	addic	%0,%0,1\n\
 	stdcx.	%0,0,%1 \n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (t)
 	: "r" (&v->counter)
 	: "cc", "xer", "memory");
@@ -399,7 +399,7 @@
 	addic	%0,%0,-1\n\
 	stdcx.	%0,0,%1\n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (t)
 	: "r" (&v->counter)
 	: "cc", "xer", "memory");
@@ -425,7 +425,7 @@
 	blt-	2f\n\
 	stdcx.	%0,0,%1\n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	"\n\
 2:"	: "=&r" (t)
 	: "r" (&v->counter)
@@ -458,7 +458,7 @@
 	add	%0,%2,%0 \n"
 "	stdcx.	%0,0,%1 \n\
 	bne-	1b \n"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 "	subf	%0,%2,%0 \n\
 2:"
 	: "=&r" (t)
Index: linux-2.6/arch/powerpc/include/asm/bitops.h
===================================================================
--- linux-2.6.orig/arch/powerpc/include/asm/bitops.h	2009-02-20 01:50:20.000000000 +1100
+++ linux-2.6/arch/powerpc/include/asm/bitops.h	2009-02-20 02:13:22.000000000 +1100
@@ -139,7 +139,7 @@
 	PPC405_ERR77(0,%3)
 	PPC_STLCX "%1,0,%3 \n"
 	"bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (old), "=&r" (t)
 	: "r" (mask), "r" (p)
 	: "cc", "memory");
@@ -160,7 +160,7 @@
 	PPC405_ERR77(0,%3)
 	PPC_STLCX "%1,0,%3 \n"
 	"bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (old), "=&r" (t)
 	: "r" (mask), "r" (p)
 	: "cc", "memory");
@@ -182,7 +182,7 @@
 	PPC405_ERR77(0,%3)
 	PPC_STLCX "%1,0,%3 \n"
 	"bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (old), "=&r" (t)
 	: "r" (mask), "r" (p)
 	: "cc", "memory");
@@ -204,7 +204,7 @@
 	PPC405_ERR77(0,%3)
 	PPC_STLCX "%1,0,%3 \n"
 	"bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (old), "=&r" (t)
 	: "r" (mask), "r" (p)
 	: "cc", "memory");
Index: linux-2.6/arch/powerpc/include/asm/futex.h
===================================================================
--- linux-2.6.orig/arch/powerpc/include/asm/futex.h	2009-02-20 01:50:20.000000000 +1100
+++ linux-2.6/arch/powerpc/include/asm/futex.h	2009-02-20 02:13:22.000000000 +1100
@@ -97,7 +97,7 @@
         PPC405_ERR77(0,%2)
 "2:     stwcx.  %4,0,%2\n\
         bne-    1b\n"
-        ISYNC_ON_SMP
+        LWSYNC_ON_SMP
 "3:	.section .fixup,\"ax\"\n\
 4:	li	%0,%5\n\
 	b	3b\n\
Index: linux-2.6/arch/powerpc/include/asm/spinlock.h
===================================================================
--- linux-2.6.orig/arch/powerpc/include/asm/spinlock.h	2009-02-20 01:50:20.000000000 +1100
+++ linux-2.6/arch/powerpc/include/asm/spinlock.h	2009-02-20 02:13:22.000000000 +1100
@@ -65,7 +65,7 @@
 	bne-		2f\n\
 	stwcx.		%1,0,%2\n\
 	bne-		1b\n\
-	isync\n\
+	lwsync\n\
 2:"	: "=&r" (tmp)
 	: "r" (token), "r" (&lock->slock)
 	: "cr0", "memory");
@@ -193,7 +193,7 @@
 	PPC405_ERR77(0,%1)
 "	stwcx.		%0,0,%1\n\
 	bne-		1b\n\
-	isync\n\
+	lwsync\n\
 2:"	: "=&r" (tmp)
 	: "r" (&rw->lock)
 	: "cr0", "xer", "memory");
@@ -217,7 +217,7 @@
 	PPC405_ERR77(0,%1)
 "	stwcx.		%1,0,%2\n\
 	bne-		1b\n\
-	isync\n\
+	lwsync\n\
 2:"	: "=&r" (tmp)
 	: "r" (token), "r" (&rw->lock)
 	: "cr0", "memory");
Index: linux-2.6/arch/powerpc/include/asm/system.h
===================================================================
--- linux-2.6.orig/arch/powerpc/include/asm/system.h	2009-02-20 02:09:41.000000000 +1100
+++ linux-2.6/arch/powerpc/include/asm/system.h	2009-02-20 02:13:22.000000000 +1100
@@ -246,7 +246,7 @@
 	PPC405_ERR77(0,%2)
 "	stwcx.	%3,0,%2 \n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (prev), "+m" (*(volatile unsigned int *)p)
 	: "r" (p), "r" (val)
 	: "cc", "memory");
@@ -289,7 +289,7 @@
 	PPC405_ERR77(0,%2)
 "	stdcx.	%3,0,%2 \n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (prev), "+m" (*(volatile unsigned long *)p)
 	: "r" (p), "r" (val)
 	: "cc", "memory");
@@ -382,7 +382,7 @@
 	PPC405_ERR77(0,%2)
 "	stwcx.	%4,0,%2\n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	"\n\
 2:"
 	: "=&r" (prev), "+m" (*p)
@@ -427,7 +427,7 @@
 	bne-	2f\n\
 	stdcx.	%4,0,%2\n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	"\n\
 2:"
 	: "=&r" (prev), "+m" (*p)
Index: linux-2.6/arch/powerpc/include/asm/synch.h
===================================================================
--- linux-2.6.orig/arch/powerpc/include/asm/synch.h	2009-02-20 01:50:20.000000000 +1100
+++ linux-2.6/arch/powerpc/include/asm/synch.h	2009-02-20 02:13:22.000000000 +1100
@@ -38,7 +38,7 @@
 
 #ifdef CONFIG_SMP
 #define ISYNC_ON_SMP	"\n\tisync\n"
-#define LWSYNC_ON_SMP	stringify_in_c(LWSYNC) "\n"
+#define LWSYNC_ON_SMP	"\n\t" stringify_in_c(LWSYNC) "\n"
 #else
 #define ISYNC_ON_SMP
 #define LWSYNC_ON_SMP
Index: linux-2.6/arch/powerpc/include/asm/mutex.h
===================================================================
--- linux-2.6.orig/arch/powerpc/include/asm/mutex.h	2009-02-20 01:50:20.000000000 +1100
+++ linux-2.6/arch/powerpc/include/asm/mutex.h	2009-02-20 02:13:22.000000000 +1100
@@ -15,7 +15,7 @@
 	PPC405_ERR77(0,%1)
 "	stwcx.	%3,0,%1\n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	"\n\
 2:"
 	: "=&r" (t)
@@ -35,7 +35,7 @@
 	PPC405_ERR77(0,%1)
 "	stwcx.	%0,0,%1\n\
 	bne-	1b"
-	ISYNC_ON_SMP
+	LWSYNC_ON_SMP
 	: "=&r" (t)
 	: "r" (&v->counter)
 	: "cc", "memory");
Index: linux-2.6/arch/powerpc/mm/hash_low_64.S
===================================================================
--- linux-2.6.orig/arch/powerpc/mm/hash_low_64.S	2009-02-20 01:50:20.000000000 +1100
+++ linux-2.6/arch/powerpc/mm/hash_low_64.S	2009-02-20 02:13:22.000000000 +1100
@@ -110,7 +110,7 @@
 	/* Write the linux PTE atomically (setting busy) */
 	stdcx.	r30,0,r6
 	bne-	1b
-	isync
+	lwsync
 
 	/* Step 2:
 	 *
@@ -393,7 +393,7 @@
 	/* Write the linux PTE atomically (setting busy) */
 	stdcx.	r30,0,r6
 	bne-	1b
-	isync
+	lwsync
 
 	/* Step 2:
 	 *
@@ -734,7 +734,7 @@
 	/* Write the linux PTE atomically (setting busy) */
 	stdcx.	r30,0,r6
 	bne-	1b
-	isync
+	lwsync
 
 	/* Step 2:
 	 *
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