diff -urN linux-2.4.19-pre8-preempt/arch/mips/config.in linux/arch/mips/config.in
--- linux-2.4.19-pre8-preempt/arch/mips/config.in	Wed May  8 15:09:53 2002
+++ linux/arch/mips/config.in	Wed May  8 15:54:35 2002
@@ -468,6 +468,7 @@
 #	bool ' Access.Bus support' CONFIG_ACCESSBUS
 #    fi
 fi
+dep_bool 'Preemptible Kernel' CONFIG_PREEMPT $CONFIG_NEW_IRQ
 endmenu
 
 if [ "$CONFIG_ISA" = "y" ]; then
diff -urN linux-2.4.19-pre8-preempt/arch/mips/kernel/i8259.c linux/arch/mips/kernel/i8259.c
--- linux-2.4.19-pre8-preempt/arch/mips/kernel/i8259.c	Wed May  8 15:09:53 2002
+++ linux/arch/mips/kernel/i8259.c	Wed May  8 15:54:35 2002
@@ -8,6 +8,7 @@
  * Copyright (C) 1992 Linus Torvalds
  * Copyright (C) 1994 - 2000 Ralf Baechle
  */
+#include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
diff -urN linux-2.4.19-pre8-preempt/arch/mips/kernel/irq.c linux/arch/mips/kernel/irq.c
--- linux-2.4.19-pre8-preempt/arch/mips/kernel/irq.c	Wed May  8 15:09:53 2002
+++ linux/arch/mips/kernel/irq.c	Wed May  8 15:56:16 2002
@@ -8,6 +8,8 @@
  * Copyright (C) 1992 Linus Torvalds
  * Copyright (C) 1994 - 2000 Ralf Baechle
  */
+
+#include <linux/sched.h>
 #include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
@@ -19,11 +21,13 @@
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/random.h>
-#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/ptrace.h>
 
 #include <asm/atomic.h>
 #include <asm/system.h>
 #include <asm/uaccess.h>
+#include <asm/debug.h>
 
 /*
  * Controller mappings for all interrupt sources:
@@ -420,6 +424,8 @@
 	struct irqaction * action;
 	unsigned int status;
 
+	preempt_disable();
+
 	kstat.irqs[cpu][irq]++;
 	spin_lock(&desc->lock);
 	desc->handler->ack(irq);
@@ -481,6 +487,27 @@
 
 	if (softirq_pending(cpu))
 		do_softirq();
+
+#if defined(CONFIG_PREEMPT)
+	while (--current->preempt_count == 0) {
+		db_assert(intr_off());
+		db_assert(!in_interrupt());
+
+		if (current->need_resched == 0) {
+			break;
+		}
+
+		current->preempt_count ++;
+		sti();
+		if (user_mode(regs)) {
+			schedule();
+		} else {
+			preempt_schedule();
+		}
+		cli();
+	}
+#endif
+
 	return 1;
 }
 
diff -urN linux-2.4.19-pre8-preempt/arch/mips/mm/extable.c linux/arch/mips/mm/extable.c
--- linux-2.4.19-pre8-preempt/arch/mips/mm/extable.c	Wed May  8 15:09:53 2002
+++ linux/arch/mips/mm/extable.c	Wed May  8 15:54:35 2002
@@ -3,6 +3,7 @@
  */
 #include <linux/config.h>
 #include <linux/module.h>
+#include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <asm/uaccess.h>
 
diff -urN linux-2.4.19-pre8-preempt/include/asm-mips/smplock.h linux/include/asm-mips/smplock.h
--- linux-2.4.19-pre8-preempt/include/asm-mips/smplock.h	Wed May  8 15:09:11 2002
+++ linux/include/asm-mips/smplock.h	Wed May  8 15:57:41 2002
@@ -5,12 +5,21 @@
  *
  * Default SMP lock implementation
  */
+#include <linux/config.h>
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
 
 extern spinlock_t kernel_flag;
 
+#ifdef CONFIG_SMP
 #define kernel_locked()		spin_is_locked(&kernel_flag)
+#else
+#ifdef CONFIG_PREEMPT
+#define kernel_locked()         preempt_get_count()
+#else
+#define kernel_locked()         1
+#endif
+#endif
 
 /*
  * Release global kernel lock and global interrupt lock
@@ -42,8 +51,14 @@
  */
 extern __inline__ void lock_kernel(void)
 {
+#ifdef CONFIG_PREEMPT
+	if (current->lock_depth == -1)
+		spin_lock(&kernel_flag);
+	++current->lock_depth;
+#else
 	if (!++current->lock_depth)
 		spin_lock(&kernel_flag);
+#endif
 }
 
 extern __inline__ void unlock_kernel(void)
diff -urN linux-2.4.19-pre8-preempt/include/asm-mips/softirq.h linux/include/asm-mips/softirq.h
--- linux-2.4.19-pre8-preempt/include/asm-mips/softirq.h	Wed May  8 15:09:11 2002
+++ linux/include/asm-mips/softirq.h	Wed May  8 15:54:35 2002
@@ -15,6 +15,7 @@
 
 static inline void cpu_bh_disable(int cpu)
 {
+	preempt_disable();
 	local_bh_count(cpu)++;
 	barrier();
 }
@@ -23,6 +24,7 @@
 {
 	barrier();
 	local_bh_count(cpu)--;
+	preempt_enable();
 }
 
 
@@ -36,6 +38,7 @@
 	cpu = smp_processor_id();				\
 	if (!--local_bh_count(cpu) && softirq_pending(cpu))	\
 		do_softirq();					\
+	preempt_enable();                                       \
 } while (0)
 
 #define in_softirq() (local_bh_count(smp_processor_id()) != 0)
diff -urN linux-2.4.19-pre8-preempt/include/asm-mips/system.h linux/include/asm-mips/system.h
--- linux-2.4.19-pre8-preempt/include/asm-mips/system.h	Wed May  8 15:09:11 2002
+++ linux/include/asm-mips/system.h	Wed May  8 15:54:35 2002
@@ -285,4 +285,16 @@
 #define die_if_kernel(msg, regs)					\
 	__die_if_kernel(msg, regs, __FILE__ ":"__FUNCTION__, __LINE__)
 
+extern __inline__ int intr_on(void)
+{
+	unsigned long flags;
+	save_flags(flags);
+	return flags & 1;
+}
+
+extern __inline__ int intr_off(void)
+{
+	return ! intr_on();
+}
+
 #endif /* _ASM_SYSTEM_H */