x86: remove irqbalance in kernel for 32 bit

This has been deprecated for years, the user space irqbalanced utility
works better with numa, has configurable policies, etc...

Signed-off-by: Yinghai Lu <yhlu.kernel@gmai.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 0 insertions, 414 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1004888e9b13..3e0eaaa1a339 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1254,14 +1254,6 @@ config EFI
         resultant kernel should continue to boot on existing non-EFI
         platforms.
 
-config IRQBALANCE
-        def_bool y
-        prompt "Enable kernel irq balancing"
-        depends on X86_32 && SMP && X86_IO_APIC
-        help
-          The default yes will allow the kernel to do irq load balancing.
-          Saying no will keep the kernel from doing irq load balancing.
-
 config SECCOMP
         def_bool y
         prompt "Enable seccomp to safely compute untrusted bytecode"
diff --git a/arch/x86/configs/i386_defconfig b/arch/x86/configs/i386_defconfig
index 52d0359719d7..13b8c86ae985 100644
--- a/arch/x86/configs/i386_defconfig
+++ b/arch/x86/configs/i386_defconfig
@@ -287,7 +287,6 @@ CONFIG_MTRR=y
 # CONFIG_MTRR_SANITIZER is not set
 CONFIG_X86_PAT=y
 CONFIG_EFI=y
-# CONFIG_IRQBALANCE is not set
 CONFIG_SECCOMP=y
 # CONFIG_HZ_100 is not set
 # CONFIG_HZ_250 is not set
diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index 204884b1415a..668edf226067 100644
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -371,408 +371,6 @@ static void set_ioapic_affinity_irq(unsigned int irq, cpumask_t cpumask)
         spin_unlock_irqrestore(&ioapic_lock, flags);
 }
 
-#if defined(CONFIG_IRQBALANCE)
-# include <asm/processor.h>     /* kernel_thread() */
-# include <linux/kernel_stat.h> /* kstat */
-# include <linux/slab.h>                /* kmalloc() */
-# include <linux/timer.h>
-
-#define IRQBALANCE_CHECK_ARCH -999
-#define MAX_BALANCED_IRQ_INTERVAL       (5*HZ)
-#define MIN_BALANCED_IRQ_INTERVAL       (HZ/2)
-#define BALANCED_IRQ_MORE_DELTA         (HZ/10)
-#define BALANCED_IRQ_LESS_DELTA         (HZ)
-
-static int irqbalance_disabled __read_mostly = IRQBALANCE_CHECK_ARCH;
-static int physical_balance __read_mostly;
-static long balanced_irq_interval __read_mostly = MAX_BALANCED_IRQ_INTERVAL;
-
-static struct irq_cpu_info {
-        unsigned long *last_irq;
-        unsigned long *irq_delta;
-        unsigned long irq;
-} irq_cpu_data[NR_CPUS];
-
-#define CPU_IRQ(cpu)            (irq_cpu_data[cpu].irq)
-#define LAST_CPU_IRQ(cpu, irq)   (irq_cpu_data[cpu].last_irq[irq])
-#define IRQ_DELTA(cpu, irq)     (irq_cpu_data[cpu].irq_delta[irq])
-
-#define IDLE_ENOUGH(cpu,now) \
-        (idle_cpu(cpu) && ((now) - per_cpu(irq_stat, (cpu)).idle_timestamp > 1))
-
-#define IRQ_ALLOWED(cpu, allowed_mask)  cpu_isset(cpu, allowed_mask)
-
-#define CPU_TO_PACKAGEINDEX(i) (first_cpu(per_cpu(cpu_sibling_map, i)))
-
-static cpumask_t balance_irq_affinity_init __initdata = CPU_MASK_ALL;
-
-static cpumask_t *balance_irq_affinity;
-
-
-static void __init irq_affinity_init_work(void *data)
-{
-        struct dyn_array *da = data;
-
-        int i;
-        struct  balance_irq_affinity *affinity;
-
-        affinity = *da->name;
-
-        for (i = 0; i < *da->nr; i++)
-                memcpy(&affinity[i], &balance_irq_affinity_init,
-                         sizeof(struct balance_irq_affinity));
-
-}
-
-DEFINE_DYN_ARRAY(balance_irq_affinity, sizeof(struct balance_irq_affinity), nr_irqs, PAGE_SIZE, irq_affinity_init_work);
-
-
-void set_balance_irq_affinity(unsigned int irq, cpumask_t mask)
-{
-        balance_irq_affinity[irq] = mask;
-}
-
-static unsigned long move(int curr_cpu, cpumask_t allowed_mask,
-                        unsigned long now, int direction)
-{
-        int search_idle = 1;
-        int cpu = curr_cpu;
-
-        goto inside;
-
-        do {
-                if (unlikely(cpu == curr_cpu))
-                        search_idle = 0;
-inside:
-                if (direction == 1) {
-                        cpu++;
-                        if (cpu >= NR_CPUS)
-                                cpu = 0;
-                } else {
-                        cpu--;
-                        if (cpu == -1)
-                                cpu = NR_CPUS-1;
-                }
-        } while (!cpu_online(cpu) || !IRQ_ALLOWED(cpu, allowed_mask) ||
-                        (search_idle && !IDLE_ENOUGH(cpu, now)));
-
-        return cpu;
-}
-
-static inline void balance_irq(int cpu, int irq)
-{
-        unsigned long now = jiffies;
-        cpumask_t allowed_mask;
-        unsigned int new_cpu;
-
-        if (irqbalance_disabled)
-                return;
-
-        cpus_and(allowed_mask, cpu_online_map, balance_irq_affinity[irq]);
-        new_cpu = move(cpu, allowed_mask, now, 1);
-        if (cpu != new_cpu)
-                set_pending_irq(irq, cpumask_of_cpu(new_cpu));
-}
-
-static inline void rotate_irqs_among_cpus(unsigned long useful_load_threshold)
-{
-        int i, j;
-        struct irq_desc *desc;
-
-        for_each_online_cpu(i) {
-                for (j = 0; j < nr_irqs; j++) {
-                        desc = irq_to_desc(j);
-                        if (!desc->action)
-                                continue;
-                        /* Is it a significant load ?  */
-                        if (IRQ_DELTA(CPU_TO_PACKAGEINDEX(i), j) <
-                                                useful_load_threshold)
-                                continue;
-                        balance_irq(i, j);
-                }
-        }
-        balanced_irq_interval = max((long)MIN_BALANCED_IRQ_INTERVAL,
-                balanced_irq_interval - BALANCED_IRQ_LESS_DELTA);
-        return;
-}
-
-static void do_irq_balance(void)
-{
-        int i, j;
-        unsigned long max_cpu_irq = 0, min_cpu_irq = (~0);
-        unsigned long move_this_load = 0;
-        int max_loaded = 0, min_loaded = 0;
-        int load;
-        unsigned long useful_load_threshold = balanced_irq_interval + 10;
-        int selected_irq;
-        int tmp_loaded, first_attempt = 1;
-        unsigned long tmp_cpu_irq;
-        unsigned long imbalance = 0;
-        cpumask_t allowed_mask, target_cpu_mask, tmp;
-        struct irq_desc *desc;
-
-        for_each_possible_cpu(i) {
-                int package_index;
-                CPU_IRQ(i) = 0;
-                if (!cpu_online(i))
-                        continue;
-                package_index = CPU_TO_PACKAGEINDEX(i);
-                for (j = 0; j < nr_irqs; j++) {
-                        unsigned long value_now, delta;
-                        /* Is this an active IRQ or balancing disabled ? */
-                        desc = irq_to_desc(j);
-                        if (!desc->action || irq_balancing_disabled(j))
-                                continue;
-                        if (package_index == i)
-                                IRQ_DELTA(package_index, j) = 0;
-                        /* Determine the total count per processor per IRQ */
-                        value_now = (unsigned long) kstat_irqs_cpu(j, i);
-
-                        /* Determine the activity per processor per IRQ */
-                        delta = value_now - LAST_CPU_IRQ(i, j);
-
-                        /* Update last_cpu_irq[][] for the next time */
-                        LAST_CPU_IRQ(i, j) = value_now;
-
-                        /* Ignore IRQs whose rate is less than the clock */
-                        if (delta < useful_load_threshold)
-                                continue;
-                        /* update the load for the processor or package total */
-                        IRQ_DELTA(package_index, j) += delta;
-
-                        /* Keep track of the higher numbered sibling as well */
-                        if (i != package_index)
-                                CPU_IRQ(i) += delta;
-                        /*
-                         * We have sibling A and sibling B in the package
-                         *
-                         * cpu_irq[A] = load for cpu A + load for cpu B
-                         * cpu_irq[B] = load for cpu B
-                         */
-                        CPU_IRQ(package_index) += delta;
-                }
-        }
-        /* Find the least loaded processor package */
-        for_each_online_cpu(i) {
-                if (i != CPU_TO_PACKAGEINDEX(i))
-                        continue;
-                if (min_cpu_irq > CPU_IRQ(i)) {
-                        min_cpu_irq = CPU_IRQ(i);
-                        min_loaded = i;
-                }
-        }
-        max_cpu_irq = ULONG_MAX;
-
-tryanothercpu:
-        /*
-         * Look for heaviest loaded processor.
-         * We may come back to get the next heaviest loaded processor.
-         * Skip processors with trivial loads.
-         */
-        tmp_cpu_irq = 0;
-        tmp_loaded = -1;
-        for_each_online_cpu(i) {
-                if (i != CPU_TO_PACKAGEINDEX(i))
-                        continue;
-                if (max_cpu_irq <= CPU_IRQ(i))
-                        continue;
-                if (tmp_cpu_irq < CPU_IRQ(i)) {
-                        tmp_cpu_irq = CPU_IRQ(i);
-                        tmp_loaded = i;
-                }
-        }
-
-        if (tmp_loaded == -1) {
-         /*
-          * In the case of small number of heavy interrupt sources,
-          * loading some of the cpus too much. We use Ingo's original
-          * approach to rotate them around.
-          */
-                if (!first_attempt && imbalance >= useful_load_threshold) {
-                        rotate_irqs_among_cpus(useful_load_threshold);
-                        return;
-                }
-                goto not_worth_the_effort;
-        }
-
-        first_attempt = 0;              /* heaviest search */
-        max_cpu_irq = tmp_cpu_irq;      /* load */
-        max_loaded = tmp_loaded;        /* processor */
-        imbalance = (max_cpu_irq - min_cpu_irq) / 2;
-
-        /*
-         * if imbalance is less than approx 10% of max load, then
-         * observe diminishing returns action. - quit
-         */
-        if (imbalance < (max_cpu_irq >> 3))
-                goto not_worth_the_effort;
-
-tryanotherirq:
-        /* if we select an IRQ to move that can't go where we want, then
-         * see if there is another one to try.
-         */
-        move_this_load = 0;
-        selected_irq = -1;
-        for (j = 0; j < nr_irqs; j++) {
-                /* Is this an active IRQ? */
-                desc = irq_to_desc(j);
-                if (!desc->action)
-                        continue;
-                if (imbalance <= IRQ_DELTA(max_loaded, j))
-                        continue;
-                /* Try to find the IRQ that is closest to the imbalance
-                 * without going over.
-                 */
-                if (move_this_load < IRQ_DELTA(max_loaded, j)) {
-                        move_this_load = IRQ_DELTA(max_loaded, j);
-                        selected_irq = j;
-                }
-        }
-        if (selected_irq == -1)
-                goto tryanothercpu;
-
-        imbalance = move_this_load;
-
-        /* For physical_balance case, we accumulated both load
-         * values in the one of the siblings cpu_irq[],
-         * to use the same code for physical and logical processors
-         * as much as possible.
-         *
-         * NOTE: the cpu_irq[] array holds the sum of the load for
-         * sibling A and sibling B in the slot for the lowest numbered
-         * sibling (A), _AND_ the load for sibling B in the slot for
-         * the higher numbered sibling.
-         *
-         * We seek the least loaded sibling by making the comparison
-         * (A+B)/2 vs B
-         */
-        load = CPU_IRQ(min_loaded) >> 1;
-        for_each_cpu_mask(j, per_cpu(cpu_sibling_map, min_loaded)) {
-                if (load > CPU_IRQ(j)) {
-                        /* This won't change cpu_sibling_map[min_loaded] */
-                        load = CPU_IRQ(j);
-                        min_loaded = j;
-                }
-        }
-
-        cpus_and(allowed_mask,
-                cpu_online_map,
-                balance_irq_affinity[selected_irq]);
-        target_cpu_mask = cpumask_of_cpu(min_loaded);
-        cpus_and(tmp, target_cpu_mask, allowed_mask);
-
-        if (!cpus_empty(tmp)) {
-                /* mark for change destination */
-                set_pending_irq(selected_irq, cpumask_of_cpu(min_loaded));
-
-                /* Since we made a change, come back sooner to
-                 * check for more variation.
-                 */
-                balanced_irq_interval = max((long)MIN_BALANCED_IRQ_INTERVAL,
-                        balanced_irq_interval - BALANCED_IRQ_LESS_DELTA);
-                return;
-        }
-        goto tryanotherirq;
-
-not_worth_the_effort:
-        /*
-         * if we did not find an IRQ to move, then adjust the time interval
-         * upward
-         */
-        balanced_irq_interval = min((long)MAX_BALANCED_IRQ_INTERVAL,
-                balanced_irq_interval + BALANCED_IRQ_MORE_DELTA);
-        return;
-}
-
-static int balanced_irq(void *unused)
-{
-        int i;
-        unsigned long prev_balance_time = jiffies;
-        long time_remaining = balanced_irq_interval;
-        struct irq_desc *desc;
-
-        /* push everything to CPU 0 to give us a starting point.  */
-        for (i = 0 ; i < nr_irqs ; i++) {
-                desc = irq_to_desc(i);
-                desc->pending_mask = cpumask_of_cpu(0);
-                set_pending_irq(i, cpumask_of_cpu(0));
-        }
-
-        set_freezable();
-        for ( ; ; ) {
-                time_remaining = schedule_timeout_interruptible(time_remaining);
-                try_to_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;
-}
-
-static int __init balanced_irq_init(void)
-{
-        int i;
-        struct cpuinfo_x86 *c;
-        cpumask_t tmp;
-
-        cpus_shift_right(tmp, cpu_online_map, 2);
-        c = &boot_cpu_data;
-        /* When not overwritten by the command line ask subarchitecture. */
-        if (irqbalance_disabled == IRQBALANCE_CHECK_ARCH)
-                irqbalance_disabled = NO_BALANCE_IRQ;
-        if (irqbalance_disabled)
-                return 0;
-
-         /* disable irqbalance completely if there is only one processor online */
-        if (num_online_cpus() < 2) {
-                irqbalance_disabled = 1;
-                return 0;
-        }
-        /*
-         * Enable physical balance only if more than 1 physical processor
-         * is present
-         */
-        if (smp_num_siblings > 1 && !cpus_empty(tmp))
-                physical_balance = 1;
-
-        for_each_online_cpu(i) {
-                irq_cpu_data[i].irq_delta = kzalloc(sizeof(unsigned long) * nr_irqs, GFP_KERNEL);
-                irq_cpu_data[i].last_irq = kzalloc(sizeof(unsigned long) * nr_irqs, GFP_KERNEL);
-                if (irq_cpu_data[i].irq_delta == NULL || irq_cpu_data[i].last_irq == NULL) {
-                        printk(KERN_ERR "balanced_irq_init: out of memory");
-                        goto failed;
-                }
-        }
-
-        printk(KERN_INFO "Starting balanced_irq\n");
-        if (!IS_ERR(kthread_run(balanced_irq, NULL, "kirqd")))
-                return 0;
-        printk(KERN_ERR "balanced_irq_init: failed to spawn balanced_irq");
-failed:
-        for_each_possible_cpu(i) {
-                kfree(irq_cpu_data[i].irq_delta);
-                irq_cpu_data[i].irq_delta = NULL;
-                kfree(irq_cpu_data[i].last_irq);
-                irq_cpu_data[i].last_irq = NULL;
-        }
-        return 0;
-}
-
-int __devinit irqbalance_disable(char *str)
-{
-        irqbalance_disabled = 1;
-        return 1;
-}
-
-__setup("noirqbalance", irqbalance_disable);
-
-late_initcall(balanced_irq_init);
-#endif /* CONFIG_IRQBALANCE */
 #endif /* CONFIG_SMP */
 
 #ifndef CONFIG_SMP
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index f6a11b9b1f98..67465ed89310 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -35,9 +35,6 @@ static void __devinit quirk_intel_irqbalance(struct pci_dev *dev)
         if (!(word & (1 << 13))) {
                 dev_info(&dev->dev, "Intel E7520/7320/7525 detected; "
                         "disabling irq balancing and affinity\n");
-#ifdef CONFIG_IRQBALANCE
-                irqbalance_disable("");
-#endif
                 noirqdebug_setup("");
 #ifdef CONFIG_PROC_FS
                 no_irq_affinity = 1;