Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1226689 > unrolled thread

[RFC PATCH v4 0/4] arm/arm64: fix a migrating irq bug when hotplug cpu

Started byYang Yingliang <yangyingliang@huawei.com>
First post2015-09-17 08:20 +0200
Last post2015-09-18 03:20 +0200
Articles 6 — 3 participants

Back to article view | Back to linux.kernel

Contents

  [RFC PATCH v4 0/4] arm/arm64: fix a migrating irq bug when hotplug cpu Yang Yingliang <yangyingliang@huawei.com> - 2015-09-17 08:20 +0200
    [RFC PATCH v4 3/4] arm64: fix a migrating irq bug when hotplug cpu Yang Yingliang <yangyingliang@huawei.com> - 2015-09-17 12:30 +0200
      Re: [RFC PATCH v4 3/4] arm64: fix a migrating irq bug when hotplug  cpu Will Deacon <will.deacon@arm.com> - 2015-09-17 18:10 +0200
    [RFC PATCH v4 1/4] genirq: introduce CONFIG_GENERIC_IRQ_MIGRATION Yang Yingliang <yangyingliang@huawei.com> - 2015-09-17 12:40 +0200
    Re: [RFC PATCH v4 0/4] arm/arm64: fix a migrating irq bug when  hotplug cpu Thomas Gleixner <tglx@linutronix.de> - 2015-09-18 00:20 +0200
      Re: [RFC PATCH v4 0/4] arm/arm64: fix a migrating irq bug when  hotplug cpu Yang Yingliang <yangyingliang@huawei.com> - 2015-09-18 03:20 +0200

#1226689 — [RFC PATCH v4 0/4] arm/arm64: fix a migrating irq bug when hotplug cpu

FromYang Yingliang <yangyingliang@huawei.com>
Date2015-09-17 08:20 +0200
Subject[RFC PATCH v4 0/4] arm/arm64: fix a migrating irq bug when hotplug cpu
Message-ID<q9zVE-2aZ-9@gated-at.bofh.it>
----
Changes in v4:
 - select GENERIC_IRQ_MIGRATION when config GENERIC_IRQ_MIGRATION is enabled
 - add move_irqs() into kerne/irq/migration.c for cpu hotplug
 - use move_irqs() to migrate interrupts on arm/arm64 when cpu is going to down
 - split bugfix patch into seperate patches for arm and arm64

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. Then add a generic function for migrating interrupts in migration.c.
And then use the function when cpu is going to down on arm and arm64.


Yang Yingliang (4):
  genirq: introduce CONFIG_GENERIC_IRQ_MIGRATION
  genirq: add move_irqs() for cpu hotplug
  arm64: fix a migrating irq bug when hotplug cpu
  arm: fix a migrating irq bug when hotplug cpu

 arch/arm/Kconfig             |  1 +
 arch/arm/include/asm/irq.h   |  1 -
 arch/arm/kernel/irq.c        | 62 ----------------------------------------
 arch/arm/kernel/smp.c        |  2 +-
 arch/arm64/Kconfig           |  1 +
 arch/arm64/include/asm/irq.h |  1 -
 arch/arm64/kernel/irq.c      | 62 ----------------------------------------
 arch/arm64/kernel/smp.c      |  2 +-
 include/linux/irq.h          |  4 +++
 kernel/irq/Kconfig           |  5 ++++
 kernel/irq/Makefile          |  2 +-
 kernel/irq/migration.c       | 68 ++++++++++++++++++++++++++++++++++++++++++++
 12 files changed, 82 insertions(+), 129 deletions(-)

-- 
2.5.0


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [next] | [standalone]

#1226887 — [RFC PATCH v4 3/4] arm64: fix a migrating irq bug when hotplug cpu

FromYang Yingliang <yangyingliang@huawei.com>
Date2015-09-17 12:30 +0200
Subject[RFC PATCH v4 3/4] arm64: fix a migrating irq bug when hotplug cpu
Message-ID<q9EBY-Ih-27@gated-at.bofh.it>
In reply to#1226689
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 use the generic
function move_irqs() to migrate interrupts in kernel/irq/migration.c.

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/arm64/Kconfig           |  1 +
 arch/arm64/include/asm/irq.h |  1 -
 arch/arm64/kernel/irq.c      | 62 --------------------------------------------
 arch/arm64/kernel/smp.c      |  2 +-
 4 files changed, 2 insertions(+), 64 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7d95663..e0cac17 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -410,6 +410,7 @@ config NR_CPUS
 
 config HOTPLUG_CPU
 	bool "Support for hot-pluggable CPUs"
+	select GENERIC_IRQ_MIGRATION
 	help
 	  Say Y here to experiment with turning CPUs off and on.  CPUs
 	  can be controlled through /sys/devices/system/cpu.
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/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index dbdaacd..492e2e4 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -232,7 +232,7 @@ int __cpu_disable(void)
 	/*
 	 * OK - migrate IRQs away from this CPU
 	 */
-	migrate_irqs();
+	move_irqs();
 
 	/*
 	 * Remove this CPU from the vm mask set of all processes.
-- 
2.5.0


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1227172 — Re: [RFC PATCH v4 3/4] arm64: fix a migrating irq bug when hotplug cpu

FromWill Deacon <will.deacon@arm.com>
Date2015-09-17 18:10 +0200
SubjectRe: [RFC PATCH v4 3/4] arm64: fix a migrating irq bug when hotplug cpu
Message-ID<q9JV1-bo-41@gated-at.bofh.it>
In reply to#1226887
On Thu, Sep 17, 2015 at 06:19:25AM +0100, Yang Yingliang wrote:
> 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 use the generic
> function move_irqs() to migrate interrupts in kernel/irq/migration.c.
> 
> 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/arm64/Kconfig           |  1 +
>  arch/arm64/include/asm/irq.h |  1 -
>  arch/arm64/kernel/irq.c      | 62 --------------------------------------------
>  arch/arm64/kernel/smp.c      |  2 +-
>  4 files changed, 2 insertions(+), 64 deletions(-)

Removing code is always good, so:

  Acked-by: Will Deacon <will.deacon@arm.com>

but obviously this depends on the core stuff.

Will
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1226898 — [RFC PATCH v4 1/4] genirq: introduce CONFIG_GENERIC_IRQ_MIGRATION

FromYang Yingliang <yangyingliang@huawei.com>
Date2015-09-17 12:40 +0200
Subject[RFC PATCH v4 1/4] genirq: introduce CONFIG_GENERIC_IRQ_MIGRATION
Message-ID<q9ELE-TQ-27@gated-at.bofh.it>
In reply to#1226689
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>
---
 kernel/irq/Kconfig     | 5 +++++
 kernel/irq/Makefile    | 2 +-
 kernel/irq/migration.c | 2 ++
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 9a76e3b..1ac0647 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -29,6 +29,11 @@ config GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 # Support for delayed migration from interrupt context
 config GENERIC_PENDING_IRQ
 	bool
+	select GENERIC_IRQ_MIGRATION
+
+# Support for generic irq migration
+config GENERIC_IRQ_MIGRATION
+	bool
 
 # Alpha specific irq affinity mechanism
 config AUTO_IRQ_AFFINITY
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


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1227449 — Re: [RFC PATCH v4 0/4] arm/arm64: fix a migrating irq bug when hotplug cpu

FromThomas Gleixner <tglx@linutronix.de>
Date2015-09-18 00:20 +0200
SubjectRe: [RFC PATCH v4 0/4] arm/arm64: fix a migrating irq bug when hotplug cpu
Message-ID<q9PH4-g0-23@gated-at.bofh.it>
In reply to#1226689
On Thu, 17 Sep 2015, Yang Yingliang wrote:

Can you please Cc the relevant people on the cover letter as well next
time?

Thanks,

	tglx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1227510 — Re: [RFC PATCH v4 0/4] arm/arm64: fix a migrating irq bug when hotplug cpu

FromYang Yingliang <yangyingliang@huawei.com>
Date2015-09-18 03:20 +0200
SubjectRe: [RFC PATCH v4 0/4] arm/arm64: fix a migrating irq bug when hotplug cpu
Message-ID<q9Svg-4mL-25@gated-at.bofh.it>
In reply to#1227449

On 2015/9/18 6:10, Thomas Gleixner wrote:
> On Thu, 17 Sep 2015, Yang Yingliang wrote:
>
> Can you please Cc the relevant people on the cover letter as well next
> time?
>
> Thanks,
>
> 	tglx
>
>

OK, I will add Cc next time.

Thanks,
Yang

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web