From f84dbb912f344270f31d5cce974f12908a47798d Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 10 Jul 2008 14:48:54 -0700 Subject: genirq: enable polling for disabled screaming irqs When we disable a screaming irq we never see it again. If the irq line is shared or if the driver half works this is a real pain. So periodically poll the handlers for screaming interrupts. I use a timer instead of the classic irq poll technique of working off the timer interrupt because when we use the local apic timers note_interrupt is never called (bug?). Further on a system with dynamic ticks the timer interrupt might not even fire unless there is a timer telling it it needs to. I forced this case on my test system with an e1000 nic and my ssh session remained responsive despite the interrupt handler only being called every 10th of a second. Signed-off-by: Eric W. Biederman Signed-off-by: Ingo Molnar --- kernel/irq/spurious.c | 146 +++++++++++++++++++++++++++++++------------------- 1 file changed, 91 insertions(+), 55 deletions(-) (limited to 'kernel/irq/spurious.c') diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index c66d3f10e853..19fe9d6ebfe8 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -12,83 +12,117 @@ #include #include #include +#include static int irqfixup __read_mostly; +#define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10) +static void poll_spurious_irqs(unsigned long dummy); +static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0); + /* * Recovery handler for misrouted interrupts. */ -static int misrouted_irq(int irq) +static int try_one_irq(int irq, struct irq_desc *desc) { - int i; + struct irqaction *action; int ok = 0; int work = 0; /* Did we do work for a real IRQ */ - for (i = 1; i < NR_IRQS; i++) { - struct irq_desc *desc = irq_desc + i; - struct irqaction *action; - - if (i == irq) /* Already tried */ - continue; - - spin_lock(&desc->lock); - /* Already running on another processor */ - if (desc->status & IRQ_INPROGRESS) { - /* - * Already running: If it is shared get the other - * CPU to go looking for our mystery interrupt too - */ - if (desc->action && (desc->action->flags & IRQF_SHARED)) - desc->status |= IRQ_PENDING; - spin_unlock(&desc->lock); - continue; - } - /* Honour the normal IRQ locking */ - desc->status |= IRQ_INPROGRESS; - action = desc->action; + spin_lock(&desc->lock); + /* Already running on another processor */ + if (desc->status & IRQ_INPROGRESS) { + /* + * Already running: If it is shared get the other + * CPU to go looking for our mystery interrupt too + */ + if (desc->action && (desc->action->flags & IRQF_SHARED)) + desc->status |= IRQ_PENDING; spin_unlock(&desc->lock); + return ok; + } + /* Honour the normal IRQ locking */ + desc->status |= IRQ_INPROGRESS; + action = desc->action; + spin_unlock(&desc->lock); - while (action) { - /* Only shared IRQ handlers are safe to call */ - if (action->flags & IRQF_SHARED) { - if (action->handler(i, action->dev_id) == - IRQ_HANDLED) - ok = 1; - } - action = action->next; + while (action) { + /* Only shared IRQ handlers are safe to call */ + if (action->flags & IRQF_SHARED) { + if (action->handler(irq, action->dev_id) == + IRQ_HANDLED) + ok = 1; } - local_irq_disable(); - /* Now clean up the flags */ - spin_lock(&desc->lock); - action = desc->action; + action = action->next; + } + local_irq_disable(); + /* Now clean up the flags */ + spin_lock(&desc->lock); + action = desc->action; + /* + * While we were looking for a fixup someone queued a real + * IRQ clashing with our walk: + */ + while ((desc->status & IRQ_PENDING) && action) { /* - * While we were looking for a fixup someone queued a real - * IRQ clashing with our walk: - */ - while ((desc->status & IRQ_PENDING) && action) { - /* - * Perform real IRQ processing for the IRQ we deferred - */ - work = 1; - spin_unlock(&desc->lock); - handle_IRQ_event(i, action); - spin_lock(&desc->lock); - desc->status &= ~IRQ_PENDING; - } - desc->status &= ~IRQ_INPROGRESS; - /* - * If we did actual work for the real IRQ line we must let the - * IRQ controller clean up too + * Perform real IRQ processing for the IRQ we deferred */ - if (work && desc->chip && desc->chip->end) - desc->chip->end(i); + work = 1; spin_unlock(&desc->lock); + handle_IRQ_event(irq, action); + spin_lock(&desc->lock); + desc->status &= ~IRQ_PENDING; + } + desc->status &= ~IRQ_INPROGRESS; + /* + * If we did actual work for the real IRQ line we must let the + * IRQ controller clean up too + */ + if (work && desc->chip && desc->chip->end) + desc->chip->end(irq); + spin_unlock(&desc->lock); + + return ok; +} + +static int misrouted_irq(int irq) +{ + int i; + int ok = 0; + + for (i = 1; i < NR_IRQS; i++) { + struct irq_desc *desc = irq_desc + i; + + if (i == irq) /* Already tried */ + continue; + + if (try_one_irq(i, desc)) + ok = 1; } /* So the caller can adjust the irq error counts */ return ok; } +static void poll_spurious_irqs(unsigned long dummy) +{ + int i; + for (i = 1; i < NR_IRQS; i++) { + struct irq_desc *desc = irq_desc + i; + unsigned int status; + + /* Racy but it doesn't matter */ + status = desc->status; + barrier(); + if (!(status & IRQ_SPURIOUS_DISABLED)) + continue; + + try_one_irq(i, desc); + } + + mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); +} + /* * If 99,900 of the previous 100,000 interrupts have not been handled * then assume that the IRQ is stuck in some manner. Drop a diagnostic @@ -212,6 +246,8 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc, desc->status |= IRQ_DISABLED | IRQ_SPURIOUS_DISABLED; desc->depth++; desc->chip->disable(irq); + + mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); } desc->irqs_unhandled = 0; } -- cgit v1.2.2 From 85c0f90978bf50596dbd23854648020f1f9b5bfd Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:49:47 -0700 Subject: irq: introduce nr_irqs at this point nr_irqs is equal NR_IRQS convert a few easy users from NR_IRQS to dynamic nr_irqs. v2: according to Eric, we need to take care of arch without generic_hardirqs Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/spurious.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/irq/spurious.c') diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 19fe9d6ebfe8..e26ca1e90c08 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -91,7 +91,7 @@ static int misrouted_irq(int irq) int i; int ok = 0; - for (i = 1; i < NR_IRQS; i++) { + for (i = 1; i < nr_irqs; i++) { struct irq_desc *desc = irq_desc + i; if (i == irq) /* Already tried */ @@ -107,7 +107,7 @@ static int misrouted_irq(int irq) static void poll_spurious_irqs(unsigned long dummy) { int i; - for (i = 1; i < NR_IRQS; i++) { + for (i = 1; i < nr_irqs; i++) { struct irq_desc *desc = irq_desc + i; unsigned int status; -- cgit v1.2.2 From 08678b0841267c1d00d771fe01548d86043d065e Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 19 Aug 2008 20:50:05 -0700 Subject: generic: sparse irqs: use irq_desc() together with dyn_array, instead of irq_desc[] add CONFIG_HAVE_SPARSE_IRQ to for use condensed array. Get rid of irq_desc[] array assumptions. Preallocate 32 irq_desc, and irq_desc() will try to get more. ( No change in functionality is expected anywhere, except the odd build failure where we missed a code site or where a crossing commit itroduces new irq_desc[] usage. ) v2: according to Eric, change get_irq_desc() to irq_desc() Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- kernel/irq/spurious.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel/irq/spurious.c') diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index e26ca1e90c08..b5d906002e1d 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -92,11 +92,12 @@ static int misrouted_irq(int irq) int ok = 0; for (i = 1; i < nr_irqs; i++) { - struct irq_desc *desc = irq_desc + i; + struct irq_desc *desc; if (i == irq) /* Already tried */ continue; + desc = irq_to_desc(i); if (try_one_irq(i, desc)) ok = 1; } @@ -108,7 +109,7 @@ static void poll_spurious_irqs(unsigned long dummy) { int i; for (i = 1; i < nr_irqs; i++) { - struct irq_desc *desc = irq_desc + i; + struct irq_desc *desc = irq_to_desc(i); unsigned int status; /* Racy but it doesn't matter */ -- cgit v1.2.2 From e00585bb7fc3d0b601181b765a254df7ff4ea59b Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 15 Sep 2008 01:53:50 -0700 Subject: irq: fix irqpoll && sparseirq Steven Noonan reported a boot hang when using irqpoll and CONFIG_HAVE_SPARSE_IRQ=y. The irqpoll loop needs to be updated to not iterate from 1 to nr_irqs but to iterate via for_each_irq_desc(). (in the former case desc can be NULL which crashes the box) Reported-by: Steven Noonan Tested-by: Steven Noonan Signed-off-by: Ingo Molnar --- kernel/irq/spurious.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'kernel/irq/spurious.c') diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index b5d906002e1d..ec5a4bef3054 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -90,14 +90,15 @@ static int misrouted_irq(int irq) { int i; int ok = 0; + struct irq_desc *desc; - for (i = 1; i < nr_irqs; i++) { - struct irq_desc *desc; + for_each_irq_desc(i, desc) { + if (!i) + continue; if (i == irq) /* Already tried */ continue; - desc = irq_to_desc(i); if (try_one_irq(i, desc)) ok = 1; } @@ -108,10 +109,14 @@ static int misrouted_irq(int irq) static void poll_spurious_irqs(unsigned long dummy) { int i; - for (i = 1; i < nr_irqs; i++) { - struct irq_desc *desc = irq_to_desc(i); + struct irq_desc *desc; + + for_each_irq_desc(i, desc) { unsigned int status; + if (!i) + continue; + /* Racy but it doesn't matter */ status = desc->status; barrier(); @@ -278,7 +283,7 @@ static int __init irqfixup_setup(char *str) __setup("irqfixup", irqfixup_setup); module_param(irqfixup, int, 0644); -MODULE_PARM_DESC("irqfixup", "0: No fixup, 1: irqfixup mode 2: irqpoll mode"); +MODULE_PARM_DESC("irqfixup", "0: No fixup, 1: irqfixup mode, 2: irqpoll mode"); static int __init irqpoll_setup(char *str) { -- cgit v1.2.2 From d3c60047bdb03199b93497ac40bd531315d43a86 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 16 Oct 2008 09:55:00 +0200 Subject: genirq: cleanup the sparseirq modifications Signed-off-by: Thomas Gleixner --- kernel/irq/spurious.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'kernel/irq/spurious.c') diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index ec5a4bef3054..dd364c11e56e 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -26,8 +26,7 @@ static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0); static int try_one_irq(int irq, struct irq_desc *desc) { struct irqaction *action; - int ok = 0; - int work = 0; /* Did we do work for a real IRQ */ + int ok = 0, work = 0; spin_lock(&desc->lock); /* Already running on another processor */ @@ -88,9 +87,8 @@ static int try_one_irq(int irq, struct irq_desc *desc) static int misrouted_irq(int irq) { - int i; - int ok = 0; struct irq_desc *desc; + int i, ok = 0; for_each_irq_desc(i, desc) { if (!i) @@ -108,8 +106,8 @@ static int misrouted_irq(int irq) static void poll_spurious_irqs(unsigned long dummy) { - int i; struct irq_desc *desc; + int i; for_each_irq_desc(i, desc) { unsigned int status; @@ -126,7 +124,8 @@ static void poll_spurious_irqs(unsigned long dummy) try_one_irq(i, desc); } - mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); + mod_timer(&poll_spurious_irq_timer, + jiffies + POLL_SPURIOUS_IRQ_INTERVAL); } /* @@ -177,7 +176,9 @@ report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) } } -static inline int try_misrouted_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) +static inline int +try_misrouted_irq(unsigned int irq, struct irq_desc *desc, + irqreturn_t action_ret) { struct irqaction *action; @@ -253,7 +254,8 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc, desc->depth++; desc->chip->disable(irq); - mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); + mod_timer(&poll_spurious_irq_timer, + jiffies + POLL_SPURIOUS_IRQ_INTERVAL); } desc->irqs_unhandled = 0; } -- cgit v1.2.2