ChangeSet 1.1691, 2005/06/07 16:30:17+01:00, kaf24@xxxxxxxxxxxxxxxxxxxx
Reove IRQ balancer from Xen. It is unused, and balancing will be done
by the guests themselves.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
io_apic.c | 437 --------------------------------------------------------------
1 files changed, 437 deletions(-)
diff -Nru a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c
--- a/xen/arch/x86/io_apic.c 2005-06-07 12:02:21 -04:00
+++ b/xen/arch/x86/io_apic.c 2005-06-07 12:02:21 -04:00
@@ -232,440 +232,6 @@
spin_unlock_irqrestore(&ioapic_lock, flags);
}
-#if defined(CONFIG_IRQBALANCE)
-# include <asm/processor.h> /* kernel_thread() */
-# include <xen/kernel_stat.h> /* kstat */
-# include <xen/xmalloc.h> /* kmalloc() */
-# include <xen/timer.h> /* time_after() */
-
-# ifdef CONFIG_BALANCED_IRQ_DEBUG
-# define TDprintk(x...) do { printk("<%ld:%s:%d>: ", jiffies, __FILE__,
__LINE__); printk(x); } while (0)
-# define Dprintk(x...) do { TDprintk(x); } while (0)
-# else
-# define TDprintk(x...)
-# 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;
-static int physical_balance = 0;
-
-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) - irq_stat[(cpu)].idle_timestamp > 1))
-
-#define IRQ_ALLOWED(cpu, allowed_mask) cpu_isset(cpu, allowed_mask)
-
-#define CPU_TO_PACKAGEINDEX(i) (first_cpu(cpu_sibling_map[i]))
-
-#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)
-
-long balanced_irq_interval = MAX_BALANCED_IRQ_INTERVAL;
-
-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, 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);
- }
-}
-
-static inline void rotate_irqs_among_cpus(unsigned long useful_load_threshold)
-{
- int i, j;
- Dprintk("Rotating IRQs among CPUs.\n");
- for (i = 0; i < NR_CPUS; i++) {
- for (j = 0; cpu_online(i) && (j < NR_IRQS); j++) {
- if (!irq_desc[j].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;
-
- for (i = 0; i < NR_CPUS; 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? */
- if (!irq_desc[j].action)
- continue;
- if ( package_index == i )
- IRQ_DELTA(package_index,j) = 0;
- /* Determine the total count per processor per IRQ */
- value_now = (unsigned long) kstat_cpu(i).irqs[j];
-
- /* 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 (i = 0; i < NR_CPUS; i++) {
- if (!cpu_online(i))
- continue;
- 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 (i = 0; i < NR_CPUS; i++) {
- if (!cpu_online(i))
- continue;
- 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;
-
- Dprintk("max_loaded cpu = %d\n", max_loaded);
- Dprintk("min_loaded cpu = %d\n", min_loaded);
- Dprintk("max_cpu_irq load = %ld\n", max_cpu_irq);
- Dprintk("min_cpu_irq load = %ld\n", min_cpu_irq);
- Dprintk("load imbalance = %lu\n", imbalance);
-
- /* if imbalance is less than approx 10% of max load, then
- * observe diminishing returns action. - quit
- */
- if (imbalance < (max_cpu_irq >> 3)) {
- Dprintk("Imbalance too trivial\n");
- 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? */
- if (!irq_desc[j].action)
- continue;
- if (imbalance <= IRQ_DELTA(max_loaded,j))
- continue;
- /* Try to find the IRQ that is closest to the imbalance
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