[RFC PATCH v3 0/3] arm/arm64: fix a migrating irq bug when hotplug cpu

[RFC PATCH v3 0/3] arm/arm64: fix a migrating irq bug when hotplug cpu

[Yang Yingliang]

----
Changes in v3:
 - introduce config GENERIC_IRQ_MIGRATION for compiling migration.c
 - rename migrate_irqs in arch/ia64/kernel/irq.c to avoid compiling error

Changes in v2:
 - use the exiting helper to set IRQD_MOVE_PCNTXT flag
 - use for_each_active_irq() instead of for_each_irq_desc()
 - add some warn messages when affinity is null or do set affinity failed
----

Hi All,

There is a bug:

When cpu is disabled, all irqs will be migratged to another cpu.
In some cases, a new affinity is different, it needed to be coppied
to irq's affinity. But if the type of irq is LPI, it's affinity will
not be coppied because of irq_set_affinity's return value.



As Marc and Will suggested, I refactor the arm/arm64 migrating interrupts
code and fix the migrating irq bug while cpu is offline.

I'm trying let the core code do the migrating interrupts matter. kernel/irq/migration.c
depends on CONFIG_GENERIC_PENDING_IRQ, so I introduce config GENERIC_IRQ_MIGRATION for
compiling migration.c. On ia64, there is a migrate_irqs() in arch/ia64/kernel/irq.c,
rename it to avoid compiling error.

With the above preparation, move the migrating interrupts code into kernel/irq/migration.c
and fix the bug by using irq_do_set_affinity().

Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Hanjun Guo <hanjun.guo@linaro.org>

Yang Yingliang (3):
  genirq: introduce CONFIG_GENERIC_IRQ_MIGRATION
  ia64: rename migrate_irqs() to avoid compiling error
  arm/arm64: fix a migrating irq bug when hotplug cpu

 arch/arc/Kconfig             |  1 +
 arch/arm/Kconfig             |  1 +
 arch/arm/include/asm/irq.h   |  1 -
 arch/arm/kernel/irq.c        | 62 ----------------------------------------
 arch/arm64/Kconfig           |  1 +
 arch/arm64/include/asm/irq.h |  1 -
 arch/arm64/kernel/irq.c      | 62 ----------------------------------------
 arch/hexagon/Kconfig         |  1 +
 arch/ia64/Kconfig            |  1 +
 arch/ia64/kernel/irq.c       |  4 +--
 arch/tile/Kconfig            |  1 +
 arch/x86/Kconfig             |  1 +
 include/linux/irq.h          |  4 +++
 kernel/irq/Kconfig           |  4 +++
 kernel/irq/Makefile          |  2 +-
 kernel/irq/migration.c       | 68 ++++++++++++++++++++++++++++++++++++++++++++
 16 files changed, 86 insertions(+), 129 deletions(-)

-- 
2.5.0

[RFC PATCH v3 1/3] genirq: introduce CONFIG_GENERIC_IRQ_MIGRATION

[Yang Yingliang]

Introduce a more general config for compile kernel/irq/migration.c.
Move the CONFIG_GENERIC_PENDING_IRQ into migration.c. So we can
move other migration interrupts code into migration.c without
select CONFIG_GENERIC_PENDING_IRQ.

Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 arch/arc/Kconfig       | 1 +
 arch/hexagon/Kconfig   | 1 +
 arch/ia64/Kconfig      | 1 +
 arch/tile/Kconfig      | 1 +
 arch/x86/Kconfig       | 1 +
 kernel/irq/Kconfig     | 4 ++++
 kernel/irq/Makefile    | 2 +-
 kernel/irq/migration.c | 2 ++
 8 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 78c0621..4133070 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -20,6 +20,7 @@ config ARC
 	# for now, we don't need GENERIC_IRQ_PROBE, CONFIG_GENERIC_IRQ_CHIP
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PENDING_IRQ if SMP
+	select GENERIC_IRQ_MIGRATION if SMP
 	select GENERIC_SMP_IDLE_THREAD
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index 4dc89d1..18d3255 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -12,6 +12,7 @@ config HEXAGON
 	# select ARCH_REQUIRE_GPIOLIB
 	# select HAVE_CLK
 	# select GENERIC_PENDING_IRQ if SMP
+	# select GENERIC_IRQ_MIGRATION if SMP
 	select GENERIC_ATOMIC64
 	select HAVE_PERF_EVENTS
 	# GENERIC_ALLOCATOR is used by dma_alloc_coherent()
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index eb0249e..e48c2c8 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -37,6 +37,7 @@ config IA64
 	select ARCH_DISCARD_MEMBLOCK
 	select GENERIC_IRQ_PROBE
 	select GENERIC_PENDING_IRQ if SMP
+	select GENERIC_IRQ_MIGRATION if SMP
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_LEGACY
 	select ARCH_WANT_OPTIONAL_GPIOLIB
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 106c21b..bf8b059 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -14,6 +14,7 @@ config TILE
 	select HAVE_DEBUG_KMEMLEAK
 	select GENERIC_IRQ_PROBE
 	select GENERIC_PENDING_IRQ if SMP
+	select GENERIC_IRQ_MIGRATION if SMP
 	select GENERIC_IRQ_SHOW
 	select HAVE_DEBUG_BUGVERBOSE
 	select VIRT_TO_BUS
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7aef2d5..a217a23 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -68,6 +68,7 @@ config X86
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PENDING_IRQ		if SMP
+	select GENERIC_IRQ_MIGRATION		if SMP
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 9a76e3b..530c54a 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -30,6 +30,10 @@ config GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 config GENERIC_PENDING_IRQ
 	bool
 
+# Support for generic irq migration
+config GENERIC_IRQ_MIGRATION
+	bool
+
 # Alpha specific irq affinity mechanism
 config AUTO_IRQ_AFFINITY
        bool
diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index d121235..bdd31b7 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -4,6 +4,6 @@ obj-$(CONFIG_GENERIC_IRQ_CHIP) += generic-chip.o
 obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
 obj-$(CONFIG_IRQ_DOMAIN) += irqdomain.o
 obj-$(CONFIG_PROC_FS) += proc.o
-obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
+obj-$(CONFIG_GENERIC_IRQ_MIGRATION) += migration.o
 obj-$(CONFIG_PM_SLEEP) += pm.o
 obj-$(CONFIG_GENERIC_MSI_IRQ) += msi.o
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index 37ddb7b..1ff2b77 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -4,6 +4,7 @@
 
 #include "internals.h"
 
+#ifdef CONFIG_GENERIC_PENDING_IRQ
 void irq_move_masked_irq(struct irq_data *idata)
 {
 	struct irq_desc *desc = irq_data_to_desc(idata);
@@ -77,3 +78,4 @@ void irq_move_irq(struct irq_data *idata)
 	if (!masked)
 		idata->chip->irq_unmask(idata);
 }
+#endif
-- 
2.5.0

[RFC PATCH v3 2/3] ia64: rename migrate_irqs() to avoid compiling error

[Yang Yingliang]

To avoid multi-declaration error after adding migrate_irqs into
kernel/irq/migration.c, rename migrate_irqs() to move_irqs().

Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 arch/ia64/kernel/irq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/ia64/kernel/irq.c b/arch/ia64/kernel/irq.c
index de4fc00..005f339 100644
--- a/arch/ia64/kernel/irq.c
+++ b/arch/ia64/kernel/irq.c
@@ -98,7 +98,7 @@ unsigned int vectors_in_migration[NR_IRQS];
  * Since cpu_online_mask is already updated, we just need to check for
  * affinity that has zeros
  */
-static void migrate_irqs(void)
+static void move_irqs(void)
 {
 	int 		irq, new_cpu;
 
@@ -167,7 +167,7 @@ void fixup_irqs(void)
 	 * Phase 1: Locate IRQs bound to this cpu and
 	 * relocate them for cpu removal.
 	 */
-	migrate_irqs();
+	move_irqs();
 
 	/*
 	 * Phase 2: Perform interrupt processing for all entries reported in
-- 
2.5.0

[RFC PATCH v3 3/3] arm/arm64: fix a migrating irq bug when hotplug cpu

[Yang Yingliang]

When cpu is disabled, all irqs will be migratged to another cpu.
In some cases, a new affinity is different, it needed to be coppied
to irq's affinity. But if the type of irq is LPI, it's affinity will
not be coppied because of irq_set_affinity's return value. Fix it by
using irq_do_set_affinity.

And migrating interrupts is a core code matter, so move the code to
kernel/irq/migration.c and select CONFIG_GENERIC_IRQ_MIGRATION when
CONFIG_HOTPLUG_CPU and CONFIG_SMP is enabled.

Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 arch/arm/Kconfig             |  1 +
 arch/arm/include/asm/irq.h   |  1 -
 arch/arm/kernel/irq.c        | 62 -----------------------------------------
 arch/arm64/Kconfig           |  1 +
 arch/arm64/include/asm/irq.h |  1 -
 arch/arm64/kernel/irq.c      | 62 -----------------------------------------
 include/linux/irq.h          |  4 +++
 kernel/irq/migration.c       | 66 ++++++++++++++++++++++++++++++++++++++++++++
 8 files changed, 72 insertions(+), 126 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 72ad724..d70ddd5 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -22,6 +22,7 @@ config ARM
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
 	select GENERIC_IDLE_POLL_SETUP
 	select GENERIC_IRQ_PROBE
+	select GENERIC_IRQ_MIGRATION if SMP && HOTPLUG_CPU
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
 	select GENERIC_PCI_IOMAP
diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h
index be1d07d..882bf98 100644
--- a/arch/arm/include/asm/irq.h
+++ b/arch/arm/include/asm/irq.h
@@ -24,7 +24,6 @@
 #ifndef __ASSEMBLY__
 struct irqaction;
 struct pt_regs;
-extern void migrate_irqs(void);
 
 extern void asm_do_IRQ(unsigned int, struct pt_regs *);
 void handle_IRQ(unsigned int, struct pt_regs *);
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 5ff4826..78abea8 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -31,7 +31,6 @@
 #include <linux/smp.h>
 #include <linux/init.h>
 #include <linux/seq_file.h>
-#include <linux/ratelimit.h>
 #include <linux/errno.h>
 #include <linux/list.h>
 #include <linux/kallsyms.h>
@@ -136,64 +135,3 @@ int __init arch_probe_nr_irqs(void)
 	return nr_irqs;
 }
 #endif
-
-#ifdef CONFIG_HOTPLUG_CPU
-static bool migrate_one_irq(struct irq_desc *desc)
-{
-	struct irq_data *d = irq_desc_get_irq_data(desc);
-	const struct cpumask *affinity = irq_data_get_affinity_mask(d);
-	struct irq_chip *c;
-	bool ret = false;
-
-	/*
-	 * If this is a per-CPU interrupt, or the affinity does not
-	 * include this CPU, then we have nothing to do.
-	 */
-	if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
-		return false;
-
-	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
-		affinity = cpu_online_mask;
-		ret = true;
-	}
-
-	c = irq_data_get_irq_chip(d);
-	if (!c->irq_set_affinity)
-		pr_debug("IRQ%u: unable to set affinity\n", d->irq);
-	else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret)
-		cpumask_copy(irq_data_get_affinity_mask(d), affinity);
-
-	return ret;
-}
-
-/*
- * The current CPU has been marked offline.  Migrate IRQs off this CPU.
- * If the affinity settings do not allow other CPUs, force them onto any
- * available CPU.
- *
- * Note: we must iterate over all IRQs, whether they have an attached
- * action structure or not, as we need to get chained interrupts too.
- */
-void migrate_irqs(void)
-{
-	unsigned int i;
-	struct irq_desc *desc;
-	unsigned long flags;
-
-	local_irq_save(flags);
-
-	for_each_irq_desc(i, desc) {
-		bool affinity_broken;
-
-		raw_spin_lock(&desc->lock);
-		affinity_broken = migrate_one_irq(desc);
-		raw_spin_unlock(&desc->lock);
-
-		if (affinity_broken)
-			pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n",
-				i, smp_processor_id());
-	}
-
-	local_irq_restore(flags);
-}
-#endif /* CONFIG_HOTPLUG_CPU */
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7d95663..70d5b23 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -33,6 +33,7 @@ config ARM64
 	select GENERIC_CPU_AUTOPROBE
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_IRQ_PROBE
+	select GENERIC_IRQ_MIGRATION if SMP && HOTPLUG_CPU
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
 	select GENERIC_PCI_IOMAP
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
index bbb251b..0916929 100644
--- a/arch/arm64/include/asm/irq.h
+++ b/arch/arm64/include/asm/irq.h
@@ -7,7 +7,6 @@
 
 struct pt_regs;
 
-extern void migrate_irqs(void);
 extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));
 
 static inline void acpi_irq_init(void)
diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index 11dc3fd..9f17ec0 100644
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -27,7 +27,6 @@
 #include <linux/init.h>
 #include <linux/irqchip.h>
 #include <linux/seq_file.h>
-#include <linux/ratelimit.h>
 
 unsigned long irq_err_count;
 
@@ -54,64 +53,3 @@ void __init init_IRQ(void)
 	if (!handle_arch_irq)
 		panic("No interrupt controller found.");
 }
-
-#ifdef CONFIG_HOTPLUG_CPU
-static bool migrate_one_irq(struct irq_desc *desc)
-{
-	struct irq_data *d = irq_desc_get_irq_data(desc);
-	const struct cpumask *affinity = irq_data_get_affinity_mask(d);
-	struct irq_chip *c;
-	bool ret = false;
-
-	/*
-	 * If this is a per-CPU interrupt, or the affinity does not
-	 * include this CPU, then we have nothing to do.
-	 */
-	if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
-		return false;
-
-	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
-		affinity = cpu_online_mask;
-		ret = true;
-	}
-
-	c = irq_data_get_irq_chip(d);
-	if (!c->irq_set_affinity)
-		pr_debug("IRQ%u: unable to set affinity\n", d->irq);
-	else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret)
-		cpumask_copy(irq_data_get_affinity_mask(d), affinity);
-
-	return ret;
-}
-
-/*
- * The current CPU has been marked offline.  Migrate IRQs off this CPU.
- * If the affinity settings do not allow other CPUs, force them onto any
- * available CPU.
- *
- * Note: we must iterate over all IRQs, whether they have an attached
- * action structure or not, as we need to get chained interrupts too.
- */
-void migrate_irqs(void)
-{
-	unsigned int i;
-	struct irq_desc *desc;
-	unsigned long flags;
-
-	local_irq_save(flags);
-
-	for_each_irq_desc(i, desc) {
-		bool affinity_broken;
-
-		raw_spin_lock(&desc->lock);
-		affinity_broken = migrate_one_irq(desc);
-		raw_spin_unlock(&desc->lock);
-
-		if (affinity_broken)
-			pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n",
-					    i, smp_processor_id());
-	}
-
-	local_irq_restore(flags);
-}
-#endif /* CONFIG_HOTPLUG_CPU */
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 6f8b340..59e5e52 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -446,6 +446,10 @@ static inline void irq_move_irq(struct irq_data *data) { }
 static inline void irq_move_masked_irq(struct irq_data *data) { }
 #endif
 
+#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_IRQ_MIGRATION) && defined(CONFIG_HOTPLUG_CPU)
+void migrate_irqs(void);
+#endif
+
 extern int no_irq_affinity;
 
 #ifdef CONFIG_HARDIRQS_SW_RESEND
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index 1ff2b77..89c9765 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -1,6 +1,7 @@
 
 #include <linux/irq.h>
 #include <linux/interrupt.h>
+#include <linux/ratelimit.h>
 
 #include "internals.h"
 
@@ -79,3 +80,68 @@ void irq_move_irq(struct irq_data *idata)
 		idata->chip->irq_unmask(idata);
 }
 #endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+static bool migrate_one_irq(struct irq_desc *desc)
+{
+	struct irq_data *d = irq_desc_get_irq_data(desc);
+	const struct cpumask *affinity = d->affinity;
+	struct irq_chip *c;
+	bool ret = false;
+
+	/*
+	 * If this is a per-CPU interrupt, or the affinity does not
+	 * include this CPU, then we have nothing to do.
+	 */
+	if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
+		return false;
+
+	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
+		affinity = cpu_online_mask;
+		ret = true;
+	}
+
+	c = irq_data_get_irq_chip(d);
+	if (!c->irq_set_affinity) {
+		pr_warn_ratelimited("IRQ%u: unable to set affinity\n", d->irq);
+	} else {
+		int r = irq_do_set_affinity(d, affinity, false);
+		if (r)
+			pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n", d->irq, r);
+	}
+
+	return ret;
+}
+
+/*
+ * The current CPU has been marked offline.  Migrate IRQs off this CPU.
+ * If the affinity settings do not allow other CPUs, force them onto any
+ * available CPU.
+ *
+ * Note: we must iterate over all IRQs, whether they have an attached
+ * action structure or not, as we need to get chained interrupts too.
+ */
+void migrate_irqs(void)
+{
+	unsigned int irq;
+	struct irq_desc *desc;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for_each_active_irq(irq) {
+		bool affinity_broken;
+
+		desc = irq_to_desc(irq);
+		raw_spin_lock(&desc->lock);
+		affinity_broken = migrate_one_irq(desc);
+		raw_spin_unlock(&desc->lock);
+
+		if (affinity_broken)
+			pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n",
+					    irq, smp_processor_id());
+	}
+
+	local_irq_restore(flags);
+}
+#endif /* CONFIG_HOTPLUG_CPU */
-- 
2.5.0

Re: [RFC PATCH v3 1/3] genirq: introduce CONFIG_GENERIC_IRQ_MIGRATION

[Thomas Gleixner]

On Wed, 16 Sep 2015, Yang Yingliang wrote:
> diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> index 78c0621..4133070 100644
> --- a/arch/arc/Kconfig
> +++ b/arch/arc/Kconfig
> @@ -20,6 +20,7 @@ config ARC
>  	# for now, we don't need GENERIC_IRQ_PROBE, CONFIG_GENERIC_IRQ_CHIP
>  	select GENERIC_IRQ_SHOW
>  	select GENERIC_PENDING_IRQ if SMP
> +	select GENERIC_IRQ_MIGRATION if SMP

What's the point of this?

> --- a/kernel/irq/Kconfig
> +++ b/kernel/irq/Kconfig
> @@ -30,6 +30,10 @@ config GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
>  config GENERIC_PENDING_IRQ
>  	bool

+	select GENERIC_IRQ_MIGRATION

Will do it automatically without touching any of the arch Kconfig
files.

Thanks,

	tglx

Re: [RFC PATCH v3 2/3] ia64: rename migrate_irqs() to avoid compiling error

[Thomas Gleixner]

On Wed, 16 Sep 2015, Yang Yingliang wrote:

> To avoid multi-declaration error after adding migrate_irqs into
> kernel/irq/migration.c, rename migrate_irqs() to move_irqs().

And why can't you chose a different name for the generic function
instead of creating useless churn in IA64?
 
Thanks,

	tglx

Re: [RFC PATCH v3 3/3] arm/arm64: fix a migrating irq bug when hotplug cpu

[Thomas Gleixner]

On Wed, 16 Sep 2015, Yang Yingliang wrote:
>  arch/arm/Kconfig             |  1 +
>  arch/arm/include/asm/irq.h   |  1 -
>  arch/arm/kernel/irq.c        | 62 -----------------------------------------
>  arch/arm64/Kconfig           |  1 +
>  arch/arm64/include/asm/irq.h |  1 -
>  arch/arm64/kernel/irq.c      | 62 -----------------------------------------
>  include/linux/irq.h          |  4 +++
>  kernel/irq/migration.c       | 66 ++++++++++++++++++++++++++++++++++++++++++++

This want's to be split into seperate patches:

#1 Provide the core infrastructure

#2 Switch ARM to use it

#3 Switch ARM64 to use it

Thanks,

	tglx

Re: [RFC PATCH v3 1/3] genirq: introduce CONFIG_GENERIC_IRQ_MIGRATION

[Yang Yingliang]

On 2015/9/16 16:13, Thomas Gleixner wrote:
> On Wed, 16 Sep 2015, Yang Yingliang wrote:
>> diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
>> index 78c0621..4133070 100644
>> --- a/arch/arc/Kconfig
>> +++ b/arch/arc/Kconfig
>> @@ -20,6 +20,7 @@ config ARC
>>   	# for now, we don't need GENERIC_IRQ_PROBE, CONFIG_GENERIC_IRQ_CHIP
>>   	select GENERIC_IRQ_SHOW
>>   	select GENERIC_PENDING_IRQ if SMP
>> +	select GENERIC_IRQ_MIGRATION if SMP
>
> What's the point of this?
>
>> --- a/kernel/irq/Kconfig
>> +++ b/kernel/irq/Kconfig
>> @@ -30,6 +30,10 @@ config GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
>>   config GENERIC_PENDING_IRQ
>>   	bool
>
> +	select GENERIC_IRQ_MIGRATION
>
> Will do it automatically without touching any of the arch Kconfig
> files.

Your way is better, I will use this method.

Thanks,
Yang
>
> Thanks,
>
> 	tglx
>
> .
>

Re: [RFC PATCH v3 2/3] ia64: rename migrate_irqs() to avoid compiling error

[Yang Yingliang]

On 2015/9/16 16:21, Thomas Gleixner wrote:
> On Wed, 16 Sep 2015, Yang Yingliang wrote:
>
>> To avoid multi-declaration error after adding migrate_irqs into
>> kernel/irq/migration.c, rename migrate_irqs() to move_irqs().
>
> And why can't you chose a different name for the generic function
> instead of creating useless churn in IA64?

I am not sure which way is better at first. Never mind, I will chose a 
new name for the generic function.

Thanks,
Yang
>
> Thanks,
>
> 	tglx
>
> .
>

Re: [RFC PATCH v3 3/3] arm/arm64: fix a migrating irq bug when hotplug cpu

[Yang Yingliang]

On 2015/9/16 16:21, Thomas Gleixner wrote:
> On Wed, 16 Sep 2015, Yang Yingliang wrote:
>>   arch/arm/Kconfig             |  1 +
>>   arch/arm/include/asm/irq.h   |  1 -
>>   arch/arm/kernel/irq.c        | 62 -----------------------------------------
>>   arch/arm64/Kconfig           |  1 +
>>   arch/arm64/include/asm/irq.h |  1 -
>>   arch/arm64/kernel/irq.c      | 62 -----------------------------------------
>>   include/linux/irq.h          |  4 +++
>>   kernel/irq/migration.c       | 66 ++++++++++++++++++++++++++++++++++++++++++++
>
> This want's to be split into seperate patches:
>
> #1 Provide the core infrastructure
>
> #2 Switch ARM to use it
>
> #3 Switch ARM64 to use it

OK, thanks for suggestion !
I will change it next verison.

Thanks,
Yang
>
> Thanks,
>
> 	tglx
>
> .
>