From 54d5d42404e7705cf3804593189e963350d470e5 Mon Sep 17 00:00:00 2001 From: Ashok Raj Date: Tue, 6 Sep 2005 15:16:15 -0700 Subject: [PATCH] x86/x86_64: deferred handling of writes to /proc/irqxx/smp_affinity When handling writes to /proc/irq, current code is re-programming rte entries directly. This is not recommended and could potentially cause chipset's to lockup, or cause missing interrupts. CONFIG_IRQ_BALANCE does this correctly, where it re-programs only when the interrupt is pending. The same needs to be done for /proc/irq handling as well. Otherwise user space irq balancers are really not doing the right thing. - Changed pending_irq_balance_cpumask to pending_irq_migrate_cpumask for lack of a generic name. - added move_irq out of IRQ_BALANCE, and added this same to X86_64 - Added new proc handler for write, so we can do deferred write at irq handling time. - Display of /proc/irq/XX/smp_affinity used to display CPU_MASKALL, instead it now shows only active cpu masks, or exactly what was set. - Provided a common move_irq implementation, instead of duplicating when using generic irq framework. Tested on i386/x86_64 and ia64 with CONFIG_PCI_MSI turned on and off. Tested UP builds as well. MSI testing: tbd: I have cards, need to look for a x-over cable, although I did test an earlier version of this patch. Will test in a couple days. Signed-off-by: Ashok Raj Acked-by: Zwane Mwaikambo Grudgingly-acked-by: Andi Kleen Signed-off-by: Coywolf Qi Hunt Signed-off-by: Ashok Raj Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/io_apic.c | 55 ++++++++++++++++++++++++---------------------- 1 file changed, 29 insertions(+), 26 deletions(-) (limited to 'arch/i386/kernel') diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c index 6578f40bd501..4a5940431579 100644 --- a/arch/i386/kernel/io_apic.c +++ b/arch/i386/kernel/io_apic.c @@ -33,6 +33,7 @@ #include #include #include + #include #include #include @@ -222,13 +223,21 @@ static void clear_IO_APIC (void) clear_IO_APIC_pin(apic, pin); } +#ifdef CONFIG_SMP static void set_ioapic_affinity_irq(unsigned int irq, cpumask_t cpumask) { unsigned long flags; int pin; struct irq_pin_list *entry = irq_2_pin + irq; unsigned int apicid_value; + cpumask_t tmp; + cpus_and(tmp, cpumask, cpu_online_map); + if (cpus_empty(tmp)) + tmp = TARGET_CPUS; + + cpus_and(cpumask, tmp, CPU_MASK_ALL); + apicid_value = cpu_mask_to_apicid(cpumask); /* Prepare to do the io_apic_write */ apicid_value = apicid_value << 24; @@ -242,6 +251,7 @@ static void set_ioapic_affinity_irq(unsigned int irq, cpumask_t cpumask) break; entry = irq_2_pin + entry->next; } + set_irq_info(irq, cpumask); spin_unlock_irqrestore(&ioapic_lock, flags); } @@ -259,7 +269,6 @@ static void set_ioapic_affinity_irq(unsigned int irq, cpumask_t cpumask) # define Dprintk(x...) # endif -cpumask_t __cacheline_aligned pending_irq_balance_cpumask[NR_IRQS]; #define IRQBALANCE_CHECK_ARCH -999 static int irqbalance_disabled = IRQBALANCE_CHECK_ARCH; @@ -328,12 +337,7 @@ static inline void balance_irq(int cpu, int irq) cpus_and(allowed_mask, cpu_online_map, irq_affinity[irq]); new_cpu = move(cpu, allowed_mask, now, 1); if (cpu != new_cpu) { - irq_desc_t *desc = irq_desc + irq; - unsigned long flags; - - spin_lock_irqsave(&desc->lock, flags); - pending_irq_balance_cpumask[irq] = cpumask_of_cpu(new_cpu); - spin_unlock_irqrestore(&desc->lock, flags); + set_pending_irq(irq, cpumask_of_cpu(new_cpu)); } } @@ -528,16 +532,12 @@ tryanotherirq: cpus_and(tmp, target_cpu_mask, allowed_mask); if (!cpus_empty(tmp)) { - irq_desc_t *desc = irq_desc + selected_irq; - unsigned long flags; Dprintk("irq = %d moved to cpu = %d\n", selected_irq, min_loaded); /* mark for change destination */ - spin_lock_irqsave(&desc->lock, flags); - pending_irq_balance_cpumask[selected_irq] = - cpumask_of_cpu(min_loaded); - spin_unlock_irqrestore(&desc->lock, flags); + set_pending_irq(selected_irq, cpumask_of_cpu(min_loaded)); + /* Since we made a change, come back sooner to * check for more variation. */ @@ -568,7 +568,8 @@ static int balanced_irq(void *unused) /* push everything to CPU 0 to give us a starting point. */ for (i = 0 ; i < NR_IRQS ; i++) { - pending_irq_balance_cpumask[i] = cpumask_of_cpu(0); + pending_irq_cpumask[i] = cpumask_of_cpu(0); + set_pending_irq(i, cpumask_of_cpu(0)); } for ( ; ; ) { @@ -647,20 +648,9 @@ int __init irqbalance_disable(char *str) __setup("noirqbalance", irqbalance_disable); -static inline void move_irq(int irq) -{ - /* note - we hold the desc->lock */ - if (unlikely(!cpus_empty(pending_irq_balance_cpumask[irq]))) { - set_ioapic_affinity_irq(irq, pending_irq_balance_cpumask[irq]); - cpus_clear(pending_irq_balance_cpumask[irq]); - } -} - late_initcall(balanced_irq_init); - -#else /* !CONFIG_IRQBALANCE */ -static inline void move_irq(int irq) { } #endif /* CONFIG_IRQBALANCE */ +#endif /* CONFIG_SMP */ #ifndef CONFIG_SMP void fastcall send_IPI_self(int vector) @@ -820,6 +810,7 @@ EXPORT_SYMBOL(IO_APIC_get_PCI_irq_vector); * we need to reprogram the ioredtbls to cater for the cpus which have come online * so mask in all cases should simply be TARGET_CPUS */ +#ifdef CONFIG_SMP void __init setup_ioapic_dest(void) { int pin, ioapic, irq, irq_entry; @@ -838,6 +829,7 @@ void __init setup_ioapic_dest(void) } } +#endif /* * EISA Edge/Level control register, ELCR @@ -1249,6 +1241,7 @@ static void __init setup_IO_APIC_irqs(void) spin_lock_irqsave(&ioapic_lock, flags); io_apic_write(apic, 0x11+2*pin, *(((int *)&entry)+1)); io_apic_write(apic, 0x10+2*pin, *(((int *)&entry)+0)); + set_native_irq_info(irq, TARGET_CPUS); spin_unlock_irqrestore(&ioapic_lock, flags); } } @@ -1944,6 +1937,7 @@ static void ack_edge_ioapic_vector(unsigned int vector) { int irq = vector_to_irq(vector); + move_irq(vector); ack_edge_ioapic_irq(irq); } @@ -1958,6 +1952,7 @@ static void end_level_ioapic_vector (unsigned int vector) { int irq = vector_to_irq(vector); + move_irq(vector); end_level_ioapic_irq(irq); } @@ -1975,14 +1970,17 @@ static void unmask_IO_APIC_vector (unsigned int vector) unmask_IO_APIC_irq(irq); } +#ifdef CONFIG_SMP static void set_ioapic_affinity_vector (unsigned int vector, cpumask_t cpu_mask) { int irq = vector_to_irq(vector); + set_native_irq_info(vector, cpu_mask); set_ioapic_affinity_irq(irq, cpu_mask); } #endif +#endif /* * Level and edge triggered IO-APIC interrupts need different handling, @@ -2000,7 +1998,9 @@ static struct hw_interrupt_type ioapic_edge_type = { .disable = disable_edge_ioapic, .ack = ack_edge_ioapic, .end = end_edge_ioapic, +#ifdef CONFIG_SMP .set_affinity = set_ioapic_affinity, +#endif }; static struct hw_interrupt_type ioapic_level_type = { @@ -2011,7 +2011,9 @@ static struct hw_interrupt_type ioapic_level_type = { .disable = disable_level_ioapic, .ack = mask_and_ack_level_ioapic, .end = end_level_ioapic, +#ifdef CONFIG_SMP .set_affinity = set_ioapic_affinity, +#endif }; static inline void init_IO_APIC_traps(void) @@ -2569,6 +2571,7 @@ int io_apic_set_pci_routing (int ioapic, int pin, int irq, int edge_level, int a spin_lock_irqsave(&ioapic_lock, flags); io_apic_write(ioapic, 0x11+2*pin, *(((int *)&entry)+1)); io_apic_write(ioapic, 0x10+2*pin, *(((int *)&entry)+0)); + set_native_irq_info(use_pci_vector() ? entry.vector : irq, TARGET_CPUS); spin_unlock_irqrestore(&ioapic_lock, flags); return 0; -- cgit v1.2.2