x86/irq: remove leftover code from NUMA_MIGRATE_IRQ_DESC

The original feature of migrating irq_desc dynamic was too fragile
and was causing problems: it caused crashes on systems with lots of
cards with MSI-X when user-space irq-balancer was enabled.

We now have new patches that create irq_desc according to device
numa node. This patch removes the leftover bits of the dynamic balancer.

[ Impact: remove dead code ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <49F654AF.8000808@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

8 files changed, 9 insertions, 93 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index df9e885eee14..e1b2543f8ed3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -274,16 +274,6 @@ config SPARSE_IRQ
 
           If you don't know what to do here, say N.
 
-config NUMA_MIGRATE_IRQ_DESC
-        bool "Move irq desc when changing irq smp_affinity"
-        depends on SPARSE_IRQ && NUMA
-        depends on BROKEN
-        default n
-        ---help---
-          This enables moving irq_desc to cpu/node that irq will use handled.
-
-          If you don't know what to do here, say N.
-
 config X86_MPPARSE
         bool "Enable MPS table" if ACPI
         default y
diff --git a/arch/x86/configs/x86_64_defconfig b/arch/x86/configs/x86_64_defconfig
index 9fe5d212ab4c..27b8ce0f5908 100644
--- a/arch/x86/configs/x86_64_defconfig
+++ b/arch/x86/configs/x86_64_defconfig
@@ -195,7 +195,6 @@ CONFIG_HIGH_RES_TIMERS=y
 CONFIG_GENERIC_CLOCKEVENTS_BUILD=y
 CONFIG_SMP=y
 CONFIG_SPARSE_IRQ=y
-# CONFIG_NUMA_MIGRATE_IRQ_DESC is not set
 CONFIG_X86_FIND_SMP_CONFIG=y
 CONFIG_X86_MPPARSE=y
 # CONFIG_X86_ELAN is not set
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 30da617d18e4..9fbf0f7ec7eb 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -148,9 +148,6 @@ struct irq_cfg {
         unsigned move_cleanup_count;
         u8 vector;
         u8 move_in_progress : 1;
-#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
-        u8 move_desc_pending : 1;
-#endif
 };
 
 /* irq_cfg is indexed by the sum of all RTEs in all I/O APICs. */
@@ -254,8 +251,7 @@ int arch_init_chip_data(struct irq_desc *desc, int cpu)
         return 0;
 }
 
-#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
-
+/* for move_irq_desc */
 static void
 init_copy_irq_2_pin(struct irq_cfg *old_cfg, struct irq_cfg *cfg, int cpu)
 {
@@ -356,19 +352,7 @@ void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc)
                 old_desc->chip_data = NULL;
         }
 }
-
-static void
-set_extra_move_desc(struct irq_desc *desc, const struct cpumask *mask)
-{
-        struct irq_cfg *cfg = desc->chip_data;
-
-        if (!cfg->move_in_progress) {
-                /* it means that domain is not changed */
-                if (!cpumask_intersects(desc->affinity, mask))
-                        cfg->move_desc_pending = 1;
-        }
-}
-#endif
+/* end for move_irq_desc */
 
 #else
 static struct irq_cfg *irq_cfg(unsigned int irq)
@@ -378,13 +362,6 @@ static struct irq_cfg *irq_cfg(unsigned int irq)
 
 #endif
 
-#ifndef CONFIG_NUMA_MIGRATE_IRQ_DESC
-static inline void
-set_extra_move_desc(struct irq_desc *desc, const struct cpumask *mask)
-{
-}
-#endif
-
 struct io_apic {
         unsigned int index;
         unsigned int unused[3];
@@ -592,9 +569,6 @@ set_desc_affinity(struct irq_desc *desc, const struct cpumask *mask)
         if (assign_irq_vector(irq, cfg, mask))
                 return BAD_APICID;
 
-        /* check that before desc->addinity get updated */
-        set_extra_move_desc(desc, mask);
-
         cpumask_copy(desc->affinity, mask);
 
         return apic->cpu_mask_to_apicid_and(desc->affinity, cfg->domain);
@@ -2393,8 +2367,6 @@ migrate_ioapic_irq_desc(struct irq_desc *desc, const struct cpumask *mask)
         if (assign_irq_vector(irq, cfg, mask))
                 return;
 
-        set_extra_move_desc(desc, mask);
-
         dest = apic->cpu_mask_to_apicid_and(cfg->domain, mask);
 
         irte.vector = cfg->vector;
@@ -2491,34 +2463,14 @@ static void irq_complete_move(struct irq_desc **descp)
         struct irq_cfg *cfg = desc->chip_data;
         unsigned vector, me;
 
-        if (likely(!cfg->move_in_progress)) {
-#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
-                if (likely(!cfg->move_desc_pending))
-                        return;
-
-                /* domain has not changed, but affinity did */
-                me = smp_processor_id();
-                if (cpumask_test_cpu(me, desc->affinity)) {
-                        *descp = desc = move_irq_desc(desc, me);
-                        /* get the new one */
-                        cfg = desc->chip_data;
-                        cfg->move_desc_pending = 0;
-                }
-#endif
+        if (likely(!cfg->move_in_progress))
                 return;
-        }
 
         vector = ~get_irq_regs()->orig_ax;
         me = smp_processor_id();
 
-        if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain)) {
-#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
-                *descp = desc = move_irq_desc(desc, me);
-                /* get the new one */
-                cfg = desc->chip_data;
-#endif
+        if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain))
                 send_cleanup_vector(cfg);
-        }
 }
 #else
 static inline void irq_complete_move(struct irq_desc **descp) {}
diff --git a/include/linux/irq.h b/include/linux/irq.h
index c4953cf27e5e..2a34cd6281d7 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -212,16 +212,6 @@ extern struct irq_desc *move_irq_desc(struct irq_desc *old_desc, int cpu);
 
 extern struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu);
 
-static inline struct irq_desc *
-irq_remap_to_desc(unsigned int irq, struct irq_desc *desc)
-{
-#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
-        return irq_to_desc(irq);
-#else
-        return desc;
-#endif
-}
-
 /*
  * Migration helpers for obsolete names, they will go away:
  */
diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index 3394f8f52964..2f065277f8ee 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -3,5 +3,5 @@ obj-y := handle.o manage.o spurious.o resend.o chip.o devres.o
 obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
-obj-$(CONFIG_NUMA_MIGRATE_IRQ_DESC) += numa_migrate.o
+obj-$(CONFIG_SPARSE_IRQ) += numa_migrate.o
 obj-$(CONFIG_PM_SLEEP) += pm.o
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index c687ba4363f2..13c68e71b726 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -359,7 +359,6 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
 
         spin_lock(&desc->lock);
         mask_ack_irq(desc, irq);
-        desc = irq_remap_to_desc(irq, desc);
 
         if (unlikely(desc->status & IRQ_INPROGRESS))
                 goto out_unlock;
@@ -438,7 +437,6 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
         desc->status &= ~IRQ_INPROGRESS;
 out:
         desc->chip->eoi(irq);
-        desc = irq_remap_to_desc(irq, desc);
 
         spin_unlock(&desc->lock);
 }
@@ -475,7 +473,6 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
                     !desc->action)) {
                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
                 mask_ack_irq(desc, irq);
-                desc = irq_remap_to_desc(irq, desc);
                 goto out_unlock;
         }
         kstat_incr_irqs_this_cpu(irq, desc);
@@ -483,7 +480,6 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
         /* Start handling the irq */
         if (desc->chip->ack)
                 desc->chip->ack(irq);
-        desc = irq_remap_to_desc(irq, desc);
 
         /* Mark the IRQ currently in progress.*/
         desc->status |= IRQ_INPROGRESS;
@@ -544,10 +540,8 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
         if (!noirqdebug)
                 note_interrupt(irq, desc, action_ret);
 
-        if (desc->chip->eoi) {
+        if (desc->chip->eoi)
                 desc->chip->eoi(irq);
-                desc = irq_remap_to_desc(irq, desc);
-        }
 }
 
 void
@@ -582,10 +576,8 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 
         /* Uninstall? */
         if (handle == handle_bad_irq) {
-                if (desc->chip != &no_irq_chip) {
+                if (desc->chip != &no_irq_chip)
                         mask_ack_irq(desc, irq);
-                        desc = irq_remap_to_desc(irq, desc);
-                }
                 desc->status |= IRQ_DISABLED;
                 desc->depth = 1;
         }
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 882c79800107..3e0cbc44bd73 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -458,11 +458,8 @@ unsigned int __do_IRQ(unsigned int irq)
                 /*
                  * No locking required for CPU-local interrupts:
                  */
-                if (desc->chip->ack) {
+                if (desc->chip->ack)
                         desc->chip->ack(irq);
-                        /* get new one */
-                        desc = irq_remap_to_desc(irq, desc);
-                }
                 if (likely(!(desc->status & IRQ_DISABLED))) {
                         action_ret = handle_IRQ_event(irq, desc->action);
                         if (!noirqdebug)
@@ -473,10 +470,8 @@ unsigned int __do_IRQ(unsigned int irq)
         }
 
         spin_lock(&desc->lock);
-        if (desc->chip->ack) {
+        if (desc->chip->ack)
                 desc->chip->ack(irq);
-                desc = irq_remap_to_desc(irq, desc);
-        }
         /*
          * REPLAY is when Linux resends an IRQ that was dropped earlier
          * WAITING is used by probe to mark irqs that are being tested
diff --git a/kernel/irq/numa_migrate.c b/kernel/irq/numa_migrate.c
index 5760d7251626..ce72bc3f4ced 100644
--- a/kernel/irq/numa_migrate.c
+++ b/kernel/irq/numa_migrate.c
@@ -97,9 +97,7 @@ static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
 
         /* free the old one */
         free_one_irq_desc(old_desc, desc);
-        spin_unlock(&old_desc->lock);
         kfree(old_desc);
-        spin_lock(&desc->lock);
 
         return desc;