Re: [patch] Real-Time Preemption, -RT-2.6.12-rc6-V0.7.48-00

[Michal Schmidt <xschmi00@stud.feec.vutbr.cz>]

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Hi,

I've made the soft IRQ flag feature work on x86_64. It compiles and 
boots for me.
Attached is the patch against -RT-2.6.12-rc6-V0.7.48-01.

Michal

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diff -Nurp -X linux-RT/Documentation/dontdiff linux-RT/arch/x86_64/kernel/apic.c linux-RT.mich/arch/x86_64/kernel/apic.c
--- linux-RT/arch/x86_64/kernel/apic.c	2005-06-07 14:05:16.000000000 +0200
+++ linux-RT.mich/arch/x86_64/kernel/apic.c	2005-06-08 18:51:21.000000000 +0200
@@ -478,10 +478,9 @@ static int lapic_suspend(struct sys_devi
 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
 	apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
-	local_save_flags(flags);
-	local_irq_disable();
+	raw_local_irq_save(flags);
 	disable_local_APIC();
-	local_irq_restore(flags);
+	raw_local_irq_restore(flags);
 	return 0;
 }
 
@@ -496,7 +495,7 @@ static int lapic_resume(struct sys_devic
 	/* XXX: Pavel needs this for S3 resume, but can't explain why */
 	set_fixmap_nocache(FIX_APIC_BASE, APIC_DEFAULT_PHYS_BASE);
 
-	local_irq_save(flags);
+	raw_local_irq_save(flags);
 	rdmsr(MSR_IA32_APICBASE, l, h);
 	l &= ~MSR_IA32_APICBASE_BASE;
 	l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
@@ -519,7 +518,7 @@ static int lapic_resume(struct sys_devic
 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
 	apic_write(APIC_ESR, 0);
 	apic_read(APIC_ESR);
-	local_irq_restore(flags);
+	raw_local_irq_restore(flags);
 	return 0;
 }
 
@@ -676,7 +675,7 @@ static void setup_APIC_timer(unsigned in
 {
 	unsigned long flags;
 
-	local_irq_save(flags);
+	raw_local_irq_save(flags);
 
 	/* For some reasons this doesn't work on Simics, so fake it for now */ 
 	if (!strstr(boot_cpu_data.x86_model_id, "Screwdriver")) { 
@@ -706,7 +705,7 @@ static void setup_APIC_timer(unsigned in
 
 	__setup_APIC_LVTT(clocks);
 
-	local_irq_restore(flags);
+	raw_local_irq_restore(flags);
 }
 
 /*
@@ -763,7 +762,7 @@ void __init setup_boot_APIC_clock (void)
 	printk(KERN_INFO "Using local APIC timer interrupts.\n");
 	using_apic_timer = 1;
 
-	local_irq_disable();
+	raw_local_irq_disable();
 
 	calibration_result = calibrate_APIC_clock();
 	/*
@@ -771,14 +770,14 @@ void __init setup_boot_APIC_clock (void)
 	 */
 	setup_APIC_timer(calibration_result);
 
-	local_irq_enable();
+	raw_local_irq_enable();
 }
 
 void __init setup_secondary_APIC_clock(void)
 {
-	local_irq_disable(); /* FIXME: Do we need this? --RR */
+	raw_local_irq_disable(); /* FIXME: Do we need this? --RR */
 	setup_APIC_timer(calibration_result);
-	local_irq_enable();
+	raw_local_irq_enable();
 }
 
 void __init disable_APIC_timer(void)
diff -Nurp -X linux-RT/Documentation/dontdiff linux-RT/arch/x86_64/kernel/irq.c linux-RT.mich/arch/x86_64/kernel/irq.c
--- linux-RT/arch/x86_64/kernel/irq.c	2005-03-02 08:38:07.000000000 +0100
+++ linux-RT.mich/arch/x86_64/kernel/irq.c	2005-06-08 19:13:26.000000000 +0200
@@ -43,7 +43,8 @@ int show_interrupts(struct seq_file *p, 
 	}
 
 	if (i < NR_IRQS) {
-		spin_lock_irqsave(&irq_desc[i].lock, flags);
+		raw_local_irq_save(flags);
+		spin_lock(&irq_desc[i].lock);
 		action = irq_desc[i].action;
 		if (!action) 
 			goto skip;
@@ -63,7 +64,8 @@ int show_interrupts(struct seq_file *p, 
 			seq_printf(p, ", %s", action->name);
 		seq_putc(p, '\n');
 skip:
-		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
+		spin_unlock(&irq_desc[i].lock);
+		raw_local_irq_restore(flags);
 	} else if (i == NR_IRQS) {
 		seq_printf(p, "NMI: ");
 		for (j = 0; j < NR_CPUS; j++)
diff -Nurp -X linux-RT/Documentation/dontdiff linux-RT/arch/x86_64/kernel/process.c linux-RT.mich/arch/x86_64/kernel/process.c
--- linux-RT/arch/x86_64/kernel/process.c	2005-06-08 19:28:13.000000000 +0200
+++ linux-RT.mich/arch/x86_64/kernel/process.c	2005-06-08 19:01:05.000000000 +0200
@@ -85,13 +85,13 @@ EXPORT_SYMBOL(enable_hlt);
 void default_idle(void)
 {
 	if (!atomic_read(&hlt_counter)) {
-		local_irq_disable();
+		raw_local_irq_disable();
 		if (!need_resched())
-			safe_halt();
+			raw_safe_halt();
 		else
-			local_irq_enable();
+			raw_local_irq_enable();
 	} else
-		local_irq_enable();
+		raw_local_irq_enable();
 }
 
 /*
@@ -103,7 +103,7 @@ static void poll_idle (void)
 {
 	int oldval;
 
-	local_irq_enable();
+	raw_local_irq_enable();
 
 	/*
 	 * Deal with another CPU just having chosen a thread to
@@ -164,6 +164,8 @@ void cpu_idle (void)
 {
 	/* endless idle loop with no priority at all */
 	while (1) {
+		BUG_ON(raw_irqs_disabled());
+
 		while (!need_resched()) {
 			void (*idle)(void);
 
@@ -178,7 +180,9 @@ void cpu_idle (void)
 			propagate_preempt_locks_value();
 			idle();
 		}
+		raw_local_irq_disable();
 		__schedule();
+		raw_local_irq_enable();
 	}
 }
 
@@ -191,7 +195,7 @@ void cpu_idle (void)
  */
 static void mwait_idle(void)
 {
-	local_irq_enable();
+	raw_local_irq_enable();
 
 	if (!need_resched()) {
 		set_thread_flag(TIF_POLLING_NRFLAG);
diff -Nurp -X linux-RT/Documentation/dontdiff linux-RT/arch/x86_64/kernel/signal.c linux-RT.mich/arch/x86_64/kernel/signal.c
--- linux-RT/arch/x86_64/kernel/signal.c	2005-06-07 14:05:16.000000000 +0200
+++ linux-RT.mich/arch/x86_64/kernel/signal.c	2005-06-08 18:53:24.000000000 +0200
@@ -411,6 +411,13 @@ int do_signal(struct pt_regs *regs, sigs
 	siginfo_t info;
 	int signr;
 
+#ifdef CONFIG_PREEMPT_RT
+	/*
+	 * Fully-preemptible kernel does not need interrupts disabled:
+	 */
+	raw_local_irq_enable();
+	preempt_check_resched();
+#endif
 	/*
 	 * We want the common case to go fast, which
 	 * is why we may in certain cases get here from
diff -Nurp -X linux-RT/Documentation/dontdiff linux-RT/arch/x86_64/kernel/smpboot.c linux-RT.mich/arch/x86_64/kernel/smpboot.c
--- linux-RT/arch/x86_64/kernel/smpboot.c	2005-06-07 14:05:16.000000000 +0200
+++ linux-RT.mich/arch/x86_64/kernel/smpboot.c	2005-06-08 19:23:36.000000000 +0200
@@ -207,7 +207,7 @@ static __cpuinit void sync_master(void *
 
 	go[MASTER] = 0;
 
-	local_irq_save(flags);
+	raw_local_irq_save(flags);
 	{
 		for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) {
 			while (!go[MASTER])
@@ -216,7 +216,7 @@ static __cpuinit void sync_master(void *
 			rdtscll(go[SLAVE]);
 		}
 	}
-	local_irq_restore(flags);
+	raw_local_irq_restore(flags);
 }
 
 /*
diff -Nurp -X linux-RT/Documentation/dontdiff linux-RT/arch/x86_64/kernel/smp.c linux-RT.mich/arch/x86_64/kernel/smp.c
--- linux-RT/arch/x86_64/kernel/smp.c	2005-06-08 19:28:13.000000000 +0200
+++ linux-RT.mich/arch/x86_64/kernel/smp.c	2005-06-08 19:10:50.000000000 +0200
@@ -359,9 +359,9 @@ void smp_stop_cpu(void)
 	 * Remove this CPU:
 	 */
 	cpu_clear(smp_processor_id(), cpu_online_map);
-	local_irq_disable();
+	raw_local_irq_disable();
 	disable_local_APIC();
-	local_irq_enable(); 
+	raw_local_irq_enable(); 
 }
 
 static void smp_really_stop_cpu(void *dummy)
@@ -385,9 +385,9 @@ void smp_send_stop(void)
 	if (!nolock)
 		spin_unlock(&call_lock);
 
-	local_irq_disable();
+	raw_local_irq_disable();
 	disable_local_APIC();
-	local_irq_enable();
+	raw_local_irq_enable();
 }
 
 /*
diff -Nurp -X linux-RT/Documentation/dontdiff linux-RT/arch/x86_64/kernel/traps.c linux-RT.mich/arch/x86_64/kernel/traps.c
--- linux-RT/arch/x86_64/kernel/traps.c	2005-06-08 19:28:13.000000000 +0200
+++ linux-RT.mich/arch/x86_64/kernel/traps.c	2005-06-08 19:09:25.000000000 +0200
@@ -90,7 +90,7 @@ int register_die_notifier(struct notifie
 static inline void conditional_sti(struct pt_regs *regs)
 {
 	if (regs->eflags & X86_EFLAGS_IF)
-		local_irq_enable();
+		raw_local_irq_enable();
 }
 
 static int kstack_depth_to_print = 10;
@@ -347,7 +347,7 @@ void oops_begin(void)
 {
 	int cpu = safe_smp_processor_id(); 
 	/* racy, but better than risking deadlock. */ 
-	local_irq_disable();
+	raw_local_irq_disable();
 	if (!spin_trylock(&die_lock)) { 
 		if (cpu == die_owner) 
 			/* nested oops. should stop eventually */;
diff -Nurp -X linux-RT/Documentation/dontdiff linux-RT/arch/x86_64/mm/fault.c linux-RT.mich/arch/x86_64/mm/fault.c
--- linux-RT/arch/x86_64/mm/fault.c	2005-06-08 19:28:13.000000000 +0200
+++ linux-RT.mich/arch/x86_64/mm/fault.c	2005-06-08 18:47:49.000000000 +0200
@@ -327,7 +327,7 @@ asmlinkage void do_page_fault(struct pt_
 		return;
 
 	if (likely(regs->eflags & X86_EFLAGS_IF))
-		local_irq_enable();
+		raw_local_irq_enable();
 
 	if (unlikely(page_fault_trace))
 		printk("pagefault rip:%lx rsp:%lx cs:%lu ss:%lu address %lx error %lx\n",
diff -Nurp -X linux-RT/Documentation/dontdiff linux-RT/include/asm-x86_64/system.h linux-RT.mich/include/asm-x86_64/system.h
--- linux-RT/include/asm-x86_64/system.h	2005-06-08 19:28:13.000000000 +0200
+++ linux-RT.mich/include/asm-x86_64/system.h	2005-06-08 19:22:44.000000000 +0200
@@ -309,27 +309,31 @@ static inline unsigned long __cmpxchg(vo
 #define warn_if_not_ulong(x) do { unsigned long foo; (void) (&(x) == &foo); } while (0)
 
 /* interrupt control.. */
-#define local_save_flags(x)	do { warn_if_not_ulong(x); __asm__ __volatile__("# save_flags \n\t pushfq ; popq %q0":"=g" (x): /* no input */ :"memory"); } while (0)
-#define local_irq_restore(x) 	__asm__ __volatile__("# restore_flags \n\t pushq %0 ; popfq": /* no output */ :"g" (x):"memory", "cc")
-#define local_irq_disable() 	__asm__ __volatile__("cli": : :"memory")
-#define local_irq_enable()	__asm__ __volatile__("sti": : :"memory")
+#define __raw_local_save_flags(x)	do { warn_if_not_ulong(x); __asm__ __volatile__("# save_flags \n\t pushfq ; popq %q0":"=g" (x): /* no input */ :"memory"); } while (0)
+#define __raw_local_irq_restore(x) 	__asm__ __volatile__("# restore_flags \n\t pushq %0 ; popfq": /* no output */ :"g" (x):"memory", "cc")
+#define __raw_local_irq_disable() 	__asm__ __volatile__("cli": : :"memory")
+#define __raw_local_irq_enable()	__asm__ __volatile__("sti": : :"memory")
 /* used in the idle loop; sti takes one instruction cycle to complete */
-#define safe_halt()		__asm__ __volatile__("sti; hlt": : :"memory")
+#define __raw_safe_halt()		__asm__ __volatile__("sti; hlt": : :"memory")
 
-#define irqs_disabled_flags(flags)	\
-({					\
-	!(flags & (1<<9));		\
+#define __raw_irqs_disabled_flags(flags)	\
+({						\
+	!(flags & (1<<9));			\
 })
 
-#define irqs_disabled()			\
-({					\
-	unsigned long flags;		\
-	local_save_flags(flags);	\
-	irqs_disabled_flags(flags);	\
+#define __raw_irqs_disabled()			\
+({						\
+	unsigned long flags;			\
+	__raw_local_save_flags(flags);		\
+	__raw_irqs_disabled_flags(flags);		\
 })
 
 /* For spinlocks etc */
-#define local_irq_save(x) 	do { warn_if_not_ulong(x); __asm__ __volatile__("# local_irq_save \n\t pushfq ; popq %0 ; cli":"=g" (x): /* no input */ :"memory"); } while (0)
+#define __raw_local_irq_save(x) 	do { warn_if_not_ulong(x); __asm__ __volatile__("# local_irq_save \n\t pushfq ; popq %0 ; cli":"=g" (x): /* no input */ :"memory"); } while (0)
+
+#include <linux/rt_irq.h>
+
+#define safe_halt()	do { local_irq_enable(); __asm__ __volatile__("hlt": : :"memory"); } while (0)
 
 void cpu_idle_wait(void);