diff options
Diffstat (limited to 'patches/linux-2.6.11/i386-cpu-hotplug-updated-for-mm.patch')
-rw-r--r-- | patches/linux-2.6.11/i386-cpu-hotplug-updated-for-mm.patch | 656 |
1 files changed, 656 insertions, 0 deletions
diff --git a/patches/linux-2.6.11/i386-cpu-hotplug-updated-for-mm.patch b/patches/linux-2.6.11/i386-cpu-hotplug-updated-for-mm.patch new file mode 100644 index 0000000000..ec39143743 --- /dev/null +++ b/patches/linux-2.6.11/i386-cpu-hotplug-updated-for-mm.patch @@ -0,0 +1,656 @@ + +From: Zwane Mwaikambo <zwane@linuxpower.ca> + +Find attached the i386 cpu hotplug patch updated for Ingo's latest round of +goodies. In order to avoid dumping cpu hotplug code into kernel/irq/* i +dropped the cpu_online check in do_IRQ() by modifying fixup_irqs(). The +difference being that on cpu offline, fixup_irqs() is called before we +clear the cpu from cpu_online_map and a long delay in order to ensure that +we never have any queued external interrupts on the APICs. Due to my usual +test victims being in boxes a continent away this hasn't been tested, but +i'll cover bug reports (nudge, Nathan! ;) + +1) Add CONFIG_HOTPLUG_CPU +2) disable local APIC timer on dead cpus. +3) Disable preempt around irq balancing to prevent CPUs going down. +4) Print irq stats for all possible cpus. +5) Debugging check for interrupts on offline cpus. +6) Hacky fixup_irqs() to redirect irqs when cpus go off/online. +7) play_dead() for offline cpus to spin inside. +8) Handle offline cpus set in flush_tlb_others(). +9) Grab lock earlier in smp_call_function() to prevent CPUs going down. +10) Implement __cpu_disable() and __cpu_die(). +11) Enable local interrupts in cpu_enable() after fixup_irqs() +12) Don't fiddle with NMI on dead cpu, but leave intact on other cpus. +13) Program IRQ affinity whilst cpu is still in cpu_online_map on offline. + +Signed-off-by: Zwane Mwaikambo <zwane@linuxpower.ca> +DESC +ppc64: fix hotplug cpu +EDESC +From: Zwane Mwaikambo <zwane@fsmlabs.com> + +I seem to have broken this when I moved the clearing of the dying cpu to +arch specific code. + +Signed-off-by: Zwane Mwaikambo <zwane@fsmlabs.com> +Signed-off-by: Andrew Morton <akpm@osdl.org> +--- + + 25-akpm/arch/i386/Kconfig | 9 ++ + 25-akpm/arch/i386/kernel/apic.c | 3 + 25-akpm/arch/i386/kernel/io_apic.c | 2 + 25-akpm/arch/i386/kernel/irq.c | 66 +++++++++++++++++---- + 25-akpm/arch/i386/kernel/msr.c | 2 + 25-akpm/arch/i386/kernel/process.c | 35 +++++++++++ + 25-akpm/arch/i386/kernel/smp.c | 25 +++++--- + 25-akpm/arch/i386/kernel/smpboot.c | 98 ++++++++++++++++++++++++++++++-- + 25-akpm/arch/i386/kernel/traps.c | 8 ++ + 25-akpm/arch/ia64/kernel/smpboot.c | 3 + 25-akpm/arch/ppc64/kernel/pSeries_smp.c | 5 + + 25-akpm/arch/s390/kernel/smp.c | 4 - + 25-akpm/include/asm-i386/cpu.h | 2 + 25-akpm/include/asm-i386/irq.h | 4 + + 25-akpm/include/asm-i386/smp.h | 3 + 25-akpm/kernel/cpu.c | 14 +--- + arch/ppc64/kernel/smp.c | 0 + 17 files changed, 242 insertions(+), 41 deletions(-) + +diff -puN arch/i386/Kconfig~i386-cpu-hotplug-updated-for-mm arch/i386/Kconfig +--- 25/arch/i386/Kconfig~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/i386/Kconfig 2005-02-23 02:20:06.000000000 -0800 +@@ -1205,6 +1205,15 @@ config SCx200 + This support is also available as a module. If compiled as a + module, it will be called scx200. + ++config HOTPLUG_CPU ++ bool "Support for hot-pluggable CPUs (EXPERIMENTAL)" ++ depends on SMP && HOTPLUG && EXPERIMENTAL ++ ---help--- ++ Say Y here to experiment with turning CPUs off and on. CPUs ++ can be controlled through /sys/devices/system/cpu. ++ ++ Say N. ++ + source "drivers/pcmcia/Kconfig" + + source "drivers/pci/hotplug/Kconfig" +diff -puN arch/i386/kernel/apic.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/apic.c +--- 25/arch/i386/kernel/apic.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/i386/kernel/apic.c 2005-02-23 02:20:06.000000000 -0800 +@@ -26,6 +26,7 @@ + #include <linux/mc146818rtc.h> + #include <linux/kernel_stat.h> + #include <linux/sysdev.h> ++#include <linux/cpu.h> + + #include <asm/atomic.h> + #include <asm/smp.h> +@@ -1048,7 +1049,7 @@ void __init setup_secondary_APIC_clock(v + setup_APIC_timer(calibration_result); + } + +-void __init disable_APIC_timer(void) ++void __devinit disable_APIC_timer(void) + { + if (using_apic_timer) { + unsigned long v; +diff -puN arch/i386/kernel/io_apic.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/io_apic.c +--- 25/arch/i386/kernel/io_apic.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/i386/kernel/io_apic.c 2005-02-23 02:20:06.000000000 -0800 +@@ -576,9 +576,11 @@ static int balanced_irq(void *unused) + try_to_freeze(PF_FREEZE); + if (time_after(jiffies, + prev_balance_time+balanced_irq_interval)) { ++ preempt_disable(); + do_irq_balance(); + prev_balance_time = jiffies; + time_remaining = balanced_irq_interval; ++ preempt_enable(); + } + } + return 0; +diff -puN arch/i386/kernel/irq.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/irq.c +--- 25/arch/i386/kernel/irq.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/i386/kernel/irq.c 2005-02-23 02:20:06.000000000 -0800 +@@ -15,6 +15,9 @@ + #include <linux/seq_file.h> + #include <linux/interrupt.h> + #include <linux/kernel_stat.h> ++#include <linux/notifier.h> ++#include <linux/cpu.h> ++#include <linux/delay.h> + + #ifndef CONFIG_X86_LOCAL_APIC + /* +@@ -209,9 +212,8 @@ int show_interrupts(struct seq_file *p, + + if (i == 0) { + seq_printf(p, " "); +- for (j=0; j<NR_CPUS; j++) +- if (cpu_online(j)) +- seq_printf(p, "CPU%d ",j); ++ for_each_cpu(j) ++ seq_printf(p, "CPU%d ",j); + seq_putc(p, '\n'); + } + +@@ -224,9 +226,8 @@ int show_interrupts(struct seq_file *p, + #ifndef CONFIG_SMP + seq_printf(p, "%10u ", kstat_irqs(i)); + #else +- for (j = 0; j < NR_CPUS; j++) +- if (cpu_online(j)) +- seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); ++ for_each_cpu(j) ++ seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); + #endif + seq_printf(p, " %14s", irq_desc[i].handler->typename); + seq_printf(p, " %s", action->name); +@@ -239,16 +240,13 @@ skip: + spin_unlock_irqrestore(&irq_desc[i].lock, flags); + } else if (i == NR_IRQS) { + seq_printf(p, "NMI: "); +- for (j = 0; j < NR_CPUS; j++) +- if (cpu_online(j)) +- seq_printf(p, "%10u ", nmi_count(j)); ++ for_each_cpu(j) ++ seq_printf(p, "%10u ", nmi_count(j)); + seq_putc(p, '\n'); + #ifdef CONFIG_X86_LOCAL_APIC + seq_printf(p, "LOC: "); +- for (j = 0; j < NR_CPUS; j++) +- if (cpu_online(j)) +- seq_printf(p, "%10u ", +- irq_stat[j].apic_timer_irqs); ++ for_each_cpu(j) ++ seq_printf(p, "%10u ", irq_stat[j].apic_timer_irqs); + seq_putc(p, '\n'); + #endif + seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); +@@ -258,3 +256,45 @@ skip: + } + return 0; + } ++ ++#ifdef CONFIG_HOTPLUG_CPU ++#include <mach_apic.h> ++ ++void fixup_irqs(cpumask_t map) ++{ ++ unsigned int irq; ++ static int warned; ++ ++ for (irq = 0; irq < NR_IRQS; irq++) { ++ cpumask_t mask; ++ if (irq == 2) ++ continue; ++ ++ cpus_and(mask, irq_affinity[irq], map); ++ if (any_online_cpu(mask) == NR_CPUS) { ++ printk("Breaking affinity for irq %i\n", irq); ++ mask = map; ++ } ++ if (irq_desc[irq].handler->set_affinity) ++ irq_desc[irq].handler->set_affinity(irq, mask); ++ else if (irq_desc[irq].action && !(warned++)) ++ printk("Cannot set affinity for irq %i\n", irq); ++ } ++ ++#if 0 ++ barrier(); ++ /* Ingo Molnar says: "after the IO-APIC masks have been redirected ++ [note the nop - the interrupt-enable boundary on x86 is two ++ instructions from sti] - to flush out pending hardirqs and ++ IPIs. After this point nothing is supposed to reach this CPU." */ ++ __asm__ __volatile__("sti; nop; cli"); ++ barrier(); ++#else ++ /* That doesn't seem sufficient. Give it 1ms. */ ++ local_irq_enable(); ++ mdelay(1); ++ local_irq_disable(); ++#endif ++} ++#endif ++ +diff -puN arch/i386/kernel/msr.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/msr.c +--- 25/arch/i386/kernel/msr.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/i386/kernel/msr.c 2005-02-23 02:20:06.000000000 -0800 +@@ -260,7 +260,7 @@ static struct file_operations msr_fops = + .open = msr_open, + }; + +-static int msr_class_simple_device_add(int i) ++static int __devinit msr_class_simple_device_add(int i) + { + int err = 0; + struct class_device *class_err; +diff -puN arch/i386/kernel/process.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/process.c +--- 25/arch/i386/kernel/process.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/i386/kernel/process.c 2005-02-23 02:20:06.000000000 -0800 +@@ -13,6 +13,7 @@ + + #include <stdarg.h> + ++#include <linux/cpu.h> + #include <linux/errno.h> + #include <linux/sched.h> + #include <linux/fs.h> +@@ -55,6 +56,9 @@ + #include <linux/irq.h> + #include <linux/err.h> + ++#include <asm/tlbflush.h> ++#include <asm/cpu.h> ++ + asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); + + int hlt_counter; +@@ -139,6 +143,34 @@ static void poll_idle (void) + } + } + ++#ifdef CONFIG_HOTPLUG_CPU ++#include <asm/nmi.h> ++/* We don't actually take CPU down, just spin without interrupts. */ ++static inline void play_dead(void) ++{ ++ /* Ack it */ ++ __get_cpu_var(cpu_state) = CPU_DEAD; ++ ++ /* We shouldn't have to disable interrupts while dead, but ++ * some interrupts just don't seem to go away, and this makes ++ * it "work" for testing purposes. */ ++ /* Death loop */ ++ while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE) ++ cpu_relax(); ++ ++ local_irq_disable(); ++ __flush_tlb_all(); ++ cpu_set(smp_processor_id(), cpu_online_map); ++ enable_APIC_timer(); ++ local_irq_enable(); ++} ++#else ++static inline void play_dead(void) ++{ ++ BUG(); ++} ++#endif /* CONFIG_HOTPLUG_CPU */ ++ + /* + * The idle thread. There's no useful work to be + * done, so just try to conserve power and have a +@@ -162,6 +194,9 @@ void cpu_idle (void) + if (!idle) + idle = default_idle; + ++ if (cpu_is_offline(cpu)) ++ play_dead(); ++ + irq_stat[cpu].idle_timestamp = jiffies; + idle(); + } +diff -puN arch/i386/kernel/smpboot.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/smpboot.c +--- 25/arch/i386/kernel/smpboot.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/i386/kernel/smpboot.c 2005-02-23 02:20:06.000000000 -0800 +@@ -44,6 +44,9 @@ + #include <linux/smp_lock.h> + #include <linux/irq.h> + #include <linux/bootmem.h> ++#include <linux/notifier.h> ++#include <linux/cpu.h> ++#include <linux/percpu.h> + + #include <linux/delay.h> + #include <linux/mc146818rtc.h> +@@ -89,6 +92,9 @@ extern unsigned char trampoline_end []; + static unsigned char *trampoline_base; + static int trampoline_exec; + ++/* State of each CPU. */ ++DEFINE_PER_CPU(int, cpu_state) = { 0 }; ++ + /* + * Currently trivial. Write the real->protected mode + * bootstrap into the page concerned. The caller +@@ -1095,6 +1101,9 @@ static void __init smp_boot_cpus(unsigne + who understands all this stuff should rewrite it properly. --RR 15/Jul/02 */ + void __init smp_prepare_cpus(unsigned int max_cpus) + { ++ smp_commenced_mask = cpumask_of_cpu(0); ++ cpu_callin_map = cpumask_of_cpu(0); ++ mb(); + smp_boot_cpus(max_cpus); + } + +@@ -1104,20 +1113,99 @@ void __devinit smp_prepare_boot_cpu(void + cpu_set(smp_processor_id(), cpu_callout_map); + } + +-int __devinit __cpu_up(unsigned int cpu) ++#ifdef CONFIG_HOTPLUG_CPU ++ ++/* must be called with the cpucontrol mutex held */ ++static int __devinit cpu_enable(unsigned int cpu) + { +- /* This only works at boot for x86. See "rewrite" above. */ +- if (cpu_isset(cpu, smp_commenced_mask)) { +- local_irq_enable(); +- return -ENOSYS; ++ /* get the target out of its holding state */ ++ per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; ++ wmb(); ++ ++ /* wait for the processor to ack it. timeout? */ ++ while (!cpu_online(cpu)) ++ cpu_relax(); ++ ++ fixup_irqs(cpu_online_map); ++ /* counter the disable in fixup_irqs() */ ++ local_irq_enable(); ++ return 0; ++} ++ ++int __cpu_disable(void) ++{ ++ cpumask_t map = cpu_online_map; ++ int cpu = smp_processor_id(); ++ ++ /* ++ * Perhaps use cpufreq to drop frequency, but that could go ++ * into generic code. ++ * ++ * We won't take down the boot processor on i386 due to some ++ * interrupts only being able to be serviced by the BSP. ++ * Especially so if we're not using an IOAPIC -zwane ++ */ ++ if (cpu == 0) ++ return -EBUSY; ++ ++ /* We enable the timer again on the exit path of the death loop */ ++ disable_APIC_timer(); ++ /* Allow any queued timer interrupts to get serviced */ ++ local_irq_enable(); ++ mdelay(1); ++ local_irq_disable(); ++ ++ cpu_clear(cpu, map); ++ fixup_irqs(map); ++ /* It's now safe to remove this processor from the online map */ ++ cpu_clear(cpu, cpu_online_map); ++ return 0; ++} ++ ++void __cpu_die(unsigned int cpu) ++{ ++ /* We don't do anything here: idle task is faking death itself. */ ++ unsigned int i; ++ ++ for (i = 0; i < 10; i++) { ++ /* They ack this in play_dead by setting CPU_DEAD */ ++ if (per_cpu(cpu_state, cpu) == CPU_DEAD) ++ return; ++ current->state = TASK_UNINTERRUPTIBLE; ++ schedule_timeout(HZ/10); + } ++ printk(KERN_ERR "CPU %u didn't die...\n", cpu); ++} ++#else /* ... !CONFIG_HOTPLUG_CPU */ ++int __cpu_disable(void) ++{ ++ return -ENOSYS; ++} + ++void __cpu_die(unsigned int cpu) ++{ ++ /* We said "no" in __cpu_disable */ ++ BUG(); ++} ++#endif /* CONFIG_HOTPLUG_CPU */ ++ ++int __devinit __cpu_up(unsigned int cpu) ++{ + /* In case one didn't come up */ + if (!cpu_isset(cpu, cpu_callin_map)) { ++ printk(KERN_DEBUG "skipping cpu%d, didn't come online\n", cpu); + local_irq_enable(); + return -EIO; + } + ++#ifdef CONFIG_HOTPLUG_CPU ++ /* Already up, and in cpu_quiescent now? */ ++ if (cpu_isset(cpu, smp_commenced_mask)) { ++ cpu_enable(cpu); ++ return 0; ++ } ++#endif ++ + local_irq_enable(); + /* Unleash the CPU! */ + cpu_set(cpu, smp_commenced_mask); +diff -puN arch/i386/kernel/smp.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/smp.c +--- 25/arch/i386/kernel/smp.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/i386/kernel/smp.c 2005-02-23 02:20:06.000000000 -0800 +@@ -19,6 +19,7 @@ + #include <linux/mc146818rtc.h> + #include <linux/cache.h> + #include <linux/interrupt.h> ++#include <linux/cpu.h> + + #include <asm/mtrr.h> + #include <asm/tlbflush.h> +@@ -163,7 +164,7 @@ void send_IPI_mask_bitmask(cpumask_t cpu + unsigned long flags; + + local_irq_save(flags); +- ++ WARN_ON(mask & ~cpus_addr(cpu_online_map)[0]); + /* + * Wait for idle. + */ +@@ -345,21 +346,21 @@ out: + static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm, + unsigned long va) + { +- cpumask_t tmp; + /* + * A couple of (to be removed) sanity checks: + * +- * - we do not send IPIs to not-yet booted CPUs. + * - current CPU must not be in mask + * - mask must exist :) + */ + BUG_ON(cpus_empty(cpumask)); +- +- cpus_and(tmp, cpumask, cpu_online_map); +- BUG_ON(!cpus_equal(cpumask, tmp)); + BUG_ON(cpu_isset(smp_processor_id(), cpumask)); + BUG_ON(!mm); + ++ /* If a CPU which we ran on has gone down, OK. */ ++ cpus_and(cpumask, cpumask, cpu_online_map); ++ if (cpus_empty(cpumask)) ++ return; ++ + /* + * i'm not happy about this global shared spinlock in the + * MM hot path, but we'll see how contended it is. +@@ -484,6 +485,7 @@ void smp_send_nmi_allbutself(void) + */ + void smp_send_reschedule(int cpu) + { ++ WARN_ON(cpu_is_offline(cpu)); + send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR); + } + +@@ -524,10 +526,16 @@ int smp_call_function (void (*func) (voi + */ + { + struct call_data_struct data; +- int cpus = num_online_cpus()-1; ++ int cpus; + +- if (!cpus) ++ /* Holding any lock stops cpus from going down. */ ++ spin_lock(&call_lock); ++ cpus = num_online_cpus()-1; ++ ++ if (!cpus) { ++ spin_unlock(&call_lock); + return 0; ++ } + + /* Can deadlock when called with interrupts disabled */ + WARN_ON(irqs_disabled()); +@@ -539,7 +547,6 @@ int smp_call_function (void (*func) (voi + if (wait) + atomic_set(&data.finished, 0); + +- spin_lock(&call_lock); + call_data = &data; + mb(); + +diff -puN arch/i386/kernel/traps.c~i386-cpu-hotplug-updated-for-mm arch/i386/kernel/traps.c +--- 25/arch/i386/kernel/traps.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/i386/kernel/traps.c 2005-02-23 02:20:06.000000000 -0800 +@@ -669,6 +669,14 @@ fastcall void do_nmi(struct pt_regs * re + nmi_enter(); + + cpu = smp_processor_id(); ++ ++#ifdef CONFIG_HOTPLUG_CPU ++ if (!cpu_online(cpu)) { ++ nmi_exit(); ++ return; ++ } ++#endif ++ + ++nmi_count(cpu); + + if (!nmi_callback(regs, cpu)) +diff -puN arch/ia64/kernel/smpboot.c~i386-cpu-hotplug-updated-for-mm arch/ia64/kernel/smpboot.c +--- 25/arch/ia64/kernel/smpboot.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/ia64/kernel/smpboot.c 2005-02-23 02:20:06.000000000 -0800 +@@ -590,9 +590,10 @@ int __cpu_disable(void) + if (cpu == 0) + return -EBUSY; + ++ cpu_clear(cpu, cpu_online_map); + fixup_irqs(); + local_flush_tlb_all(); +- printk ("Disabled cpu %u\n", smp_processor_id()); ++ printk("Disabled cpu %u\n", cpu); + return 0; + } + +diff -puN arch/ppc64/kernel/smp.c~i386-cpu-hotplug-updated-for-mm arch/ppc64/kernel/smp.c +diff -puN arch/s390/kernel/smp.c~i386-cpu-hotplug-updated-for-mm arch/s390/kernel/smp.c +--- 25/arch/s390/kernel/smp.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/arch/s390/kernel/smp.c 2005-02-23 02:20:06.000000000 -0800 +@@ -679,12 +679,14 @@ __cpu_disable(void) + { + unsigned long flags; + ec_creg_mask_parms cr_parms; ++ int cpu = smp_processor_id(); + + spin_lock_irqsave(&smp_reserve_lock, flags); +- if (smp_cpu_reserved[smp_processor_id()] != 0) { ++ if (smp_cpu_reserved[cpu] != 0) { + spin_unlock_irqrestore(&smp_reserve_lock, flags); + return -EBUSY; + } ++ cpu_clear(cpu, cpu_online_map); + + #ifdef CONFIG_PFAULT + /* Disable pfault pseudo page faults on this cpu. */ +diff -puN include/asm-i386/cpu.h~i386-cpu-hotplug-updated-for-mm include/asm-i386/cpu.h +--- 25/include/asm-i386/cpu.h~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/include/asm-i386/cpu.h 2005-02-23 02:20:06.000000000 -0800 +@@ -5,6 +5,7 @@ + #include <linux/cpu.h> + #include <linux/topology.h> + #include <linux/nodemask.h> ++#include <linux/percpu.h> + + #include <asm/node.h> + +@@ -17,4 +18,5 @@ extern int arch_register_cpu(int num); + extern void arch_unregister_cpu(int); + #endif + ++DECLARE_PER_CPU(int, cpu_state); + #endif /* _ASM_I386_CPU_H_ */ +diff -puN include/asm-i386/irq.h~i386-cpu-hotplug-updated-for-mm include/asm-i386/irq.h +--- 25/include/asm-i386/irq.h~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/include/asm-i386/irq.h 2005-02-23 02:20:06.000000000 -0800 +@@ -38,4 +38,8 @@ extern void release_vm86_irqs(struct tas + extern int irqbalance_disable(char *str); + #endif + ++#ifdef CONFIG_HOTPLUG_CPU ++extern void fixup_irqs(cpumask_t map); ++#endif ++ + #endif /* _ASM_IRQ_H */ +diff -puN include/asm-i386/smp.h~i386-cpu-hotplug-updated-for-mm include/asm-i386/smp.h +--- 25/include/asm-i386/smp.h~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/include/asm-i386/smp.h 2005-02-23 02:20:06.000000000 -0800 +@@ -85,6 +85,9 @@ static __inline int logical_smp_processo + } + + #endif ++ ++extern int __cpu_disable(void); ++extern void __cpu_die(unsigned int cpu); + #endif /* !__ASSEMBLY__ */ + + #define NO_PROC_ID 0xFF /* No processor magic marker */ +diff -puN kernel/cpu.c~i386-cpu-hotplug-updated-for-mm kernel/cpu.c +--- 25/kernel/cpu.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:06.000000000 -0800 ++++ 25-akpm/kernel/cpu.c 2005-02-23 02:20:06.000000000 -0800 +@@ -63,19 +63,15 @@ static int take_cpu_down(void *unused) + { + int err; + +- /* Take offline: makes arch_cpu_down somewhat easier. */ +- cpu_clear(smp_processor_id(), cpu_online_map); +- + /* Ensure this CPU doesn't handle any more interrupts. */ + err = __cpu_disable(); + if (err < 0) +- cpu_set(smp_processor_id(), cpu_online_map); +- else +- /* Force idle task to run as soon as we yield: it should +- immediately notice cpu is offline and die quickly. */ +- sched_idle_next(); ++ return err; + +- return err; ++ /* Force idle task to run as soon as we yield: it should ++ immediately notice cpu is offline and die quickly. */ ++ sched_idle_next(); ++ return 0; + } + + int cpu_down(unsigned int cpu) +diff -puN arch/ppc64/kernel/pSeries_smp.c~i386-cpu-hotplug-updated-for-mm arch/ppc64/kernel/pSeries_smp.c +--- 25/arch/ppc64/kernel/pSeries_smp.c~i386-cpu-hotplug-updated-for-mm 2005-02-23 02:20:08.000000000 -0800 ++++ 25-akpm/arch/ppc64/kernel/pSeries_smp.c 2005-02-23 02:20:08.000000000 -0800 +@@ -86,10 +86,13 @@ static int query_cpu_stopped(unsigned in + + int pSeries_cpu_disable(void) + { ++ int cpu = smp_processor_id(); ++ ++ cpu_clear(cpu, cpu_online_map); + systemcfg->processorCount--; + + /*fix boot_cpuid here*/ +- if (smp_processor_id() == boot_cpuid) ++ if (cpu == boot_cpuid) + boot_cpuid = any_online_cpu(cpu_online_map); + + /* FIXME: abstract this to not be platform specific later on */ +_ |