diff -urN 2.4.5ac4/arch/i386/kernel/entry.S 2.4.5ac5/arch/i386/kernel/entry.S
--- 2.4.5ac4/arch/i386/kernel/entry.S	Tue Nov 28 18:39:59 2000
+++ 2.4.5ac5/arch/i386/kernel/entry.S	Wed May 30 22:04:04 2001
@@ -106,10 +106,14 @@
 	popl %edi;	\
 	popl %ebp;	\
 	popl %eax;	\
+	cmpl $__KERNEL_DS,(%esp); \
+	je 4f ; \
 1:	popl %ds;	\
 2:	popl %es;	\
 	addl $4,%esp;	\
 3:	iret;		\
+4:	addl $12,%esp;	\
+	iret; \
 .section .fixup,"ax";	\
 4:	movl $0,(%esp);	\
 	jmp 1b;		\
@@ -313,9 +317,11 @@
 	pushl %esi			# push the error code
 	pushl %edx			# push the pt_regs pointer
 	movl $(__KERNEL_DS),%edx
+	cmpl %edx,%ecx
+	jz	1f
 	movl %edx,%ds
 	movl %edx,%es
-	GET_CURRENT(%ebx)
+1:	GET_CURRENT(%ebx)
 	call *%edi
 	addl $8,%esp
 	jmp ret_from_exception
diff -urN 2.4.5ac4/include/asm-i386/hw_irq.h 2.4.5ac5/include/asm-i386/hw_irq.h
--- 2.4.5ac4/include/asm-i386/hw_irq.h	Tue May 29 18:26:59 2001
+++ 2.4.5ac5/include/asm-i386/hw_irq.h	Wed May 30 22:04:16 2001
@@ -95,6 +95,10 @@
 #define __STR(x) #x
 #define STR(x) __STR(x)
 
+/* 
+ * A segment register reload is rather expensive. Try to avoid it 
+ * if possible. 
+ */ 
 #define SAVE_ALL \
 	"cld\n\t" \
 	"pushl %es\n\t" \
@@ -106,9 +110,12 @@
 	"pushl %edx\n\t" \
 	"pushl %ecx\n\t" \
 	"pushl %ebx\n\t" \
-	"movl $" STR(__KERNEL_DS) ",%edx\n\t" \
-	"movl %edx,%ds\n\t" \
-	"movl %edx,%es\n\t"
+	"movl $" STR(__KERNEL_DS) ",%eax\n\t" \
+	"cmpl %eax,7*4(%esp)\n\t"  \
+	"je 1f\n\t"  \
+	"movl %eax,%ds\n\t" \
+	"movl %eax,%es\n\t" \
+	"1:\n\t"
 
 #define IRQ_NAME2(nr) nr##_interrupt(void)
 #define IRQ_NAME(nr) IRQ_NAME2(IRQ##nr)