Make memset() detect the special-case of clear-to-zero and call __bzero() in that case.

arch/ia64/kernel/ia64_ksyms.c

@@ -6,7 +6,11 @@
 #include <linux/module.h>
 
 #include <linux/string.h>
-EXPORT_SYMBOL_NOVERS(memset);
+#undef memset
+extern void *memset (void *, int, size_t);
+EXPORT_SYMBOL_NOVERS(memset);			/* gcc generates direct calls to memset()... */
+EXPORT_SYMBOL_NOVERS(__memset_generic);
+EXPORT_SYMBOL_NOVERS(__bzero);
 EXPORT_SYMBOL(memchr);
 EXPORT_SYMBOL(memcmp);
 EXPORT_SYMBOL_NOVERS(memcpy);

arch/ia64/kernel/traps.c

@@ -214,7 +214,8 @@ ia64_ni_syscall (unsigned long arg0, unsigned long arg1, unsigned long arg2, uns
 {
 	struct pt_regs *regs = (struct pt_regs *) &stack;
 
-	printk("<sc%ld(%lx,%lx,%lx,%lx)>\n", regs->r15, arg0, arg1, arg2, arg3);
+	printk("%s(%d): <sc%ld(%lx,%lx,%lx,%lx)>\n", current->comm, current->pid,
+	       regs->r15, arg0, arg1, arg2, arg3);
 	return -ENOSYS;
 }
 

arch/ia64/lib/memset.S

@@ -9,8 +9,8 @@
  * 	in1:	byte value to use for storing
  *	in2:	length of the buffer
  *
- * Copyright (C) 1999, 2001 Hewlett-Packard Co
- * Copyright (C) 1999 Stephane Eranian <eranian@hpl.hp.com>
+ * Copyright (C) 1999, 2001, 2002 Hewlett-Packard Co
+ *	Stephane Eranian <eranian@hpl.hp.com>
  */
 
 #include <asm/asmmacro.h>
@@ -30,7 +30,19 @@
 #define saved_lc	r20
 #define tmp		r21
 
-GLOBAL_ENTRY(memset)
+GLOBAL_ENTRY(__bzero)
+	.prologue
+	.save ar.pfs, saved_pfs
+	alloc saved_pfs=ar.pfs,0,0,3,0
+	mov out2=out1
+	mov out1=0
+	/* FALL THROUGH (explicit NOPs so that next alloc is preceded by stop bit!) */
+	nop.m 0
+	nop.f 0
+	nop.i 0
+	;;
+END(__bzero)
+GLOBAL_ENTRY(__memset_generic)
 	.prologue
 	.save ar.pfs, saved_pfs
  	alloc saved_pfs=ar.pfs,3,0,0,0	// cnt is sink here
@@ -105,4 +117,7 @@ GLOBAL_ENTRY(memset)
 	;;
 (p6)	st1 [buf]=val		// only 1 byte left
 	br.ret.sptk.many rp
-END(memset)
+END(__memset_generic)
+
+	.global memset
+memset = __memset_generic		// alias needed for gcc

include/asm-ia64/string.h

@@ -5,8 +5,8 @@
  * Here is where we want to put optimized versions of the string
  * routines.
  *
- * Copyright (C) 1998-2000 Hewlett-Packard Co
- * Copyright (C) 1998-2000 David Mosberger-Tang <davidm@hpl.hp.com>
+ * Copyright (C) 1998-2000, 2002 Hewlett-Packard Co
+ *	David Mosberger-Tang <davidm@hpl.hp.com>
  */
 
 #include <linux/config.h>	/* remove this once we remove the A-step workaround... */
@@ -17,7 +17,21 @@
 #define __HAVE_ARCH_BCOPY	1 /* see arch/ia64/lib/memcpy.S */
 
 extern __kernel_size_t strlen (const char *);
-extern void *memset (void *, int, __kernel_size_t);
 extern void *memcpy (void *, const void *, __kernel_size_t);
 
+extern void *__memset_generic (void *, int, __kernel_size_t);
+extern void __bzero (void *, __kernel_size_t);
+
+#define memset(s, c, count)				\
+({							\
+	void *_s = (s);					\
+	int _c = (c);					\
+	__kernel_size_t _count = (count);		\
+							\
+	if (__builtin_constant_p(_c) && _c == 0)	\
+		__bzero(_s, _count);			\
+	else						\
+		__memset_generic(_s, _c, _count);	\
+})
+
 #endif /* _ASM_IA64_STRING_H */