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>

3 files changed, 4 insertions, 63 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) {}