From cd7eab44e9946c28d595abe3e9a43e945bc49141 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Wed, 19 Jan 2011 21:01:44 +0000 Subject: genirq: Add IRQ affinity notifiers When initiating I/O on a multiqueue and multi-IRQ device, we may want to select a queue for which the response will be handled on the same or a nearby CPU. This requires a reverse-map of IRQ affinity. Add a notification mechanism to support this. This is based closely on work by Thomas Gleixner . Signed-off-by: Ben Hutchings Cc: linux-net-drivers@solarflare.com Cc: Tom Herbert Cc: David Miller LKML-Reference: <1295470904.11126.84.camel@bwh-desktop> Signed-off-by: Thomas Gleixner --- include/linux/interrupt.h | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 55e0d42..63c5ad7 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -14,6 +14,8 @@ #include #include #include +#include +#include #include #include @@ -240,6 +242,35 @@ extern int irq_can_set_affinity(unsigned int irq); extern int irq_select_affinity(unsigned int irq); extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m); + +/** + * struct irq_affinity_notify - context for notification of IRQ affinity changes + * @irq: Interrupt to which notification applies + * @kref: Reference count, for internal use + * @work: Work item, for internal use + * @notify: Function to be called on change. This will be + * called in process context. + * @release: Function to be called on release. This will be + * called in process context. Once registered, the + * structure must only be freed when this function is + * called or later. + */ +struct irq_affinity_notify { + unsigned int irq; + struct kref kref; + struct work_struct work; + void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask); + void (*release)(struct kref *ref); +}; + +extern int +irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify); + +static inline void irq_run_affinity_notifiers(void) +{ + flush_scheduled_work(); +} + #else /* CONFIG_SMP */ static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m) @@ -255,7 +286,7 @@ static inline int irq_can_set_affinity(unsigned int irq) static inline int irq_select_affinity(unsigned int irq) { return 0; } static inline int irq_set_affinity_hint(unsigned int irq, - const struct cpumask *m) + const struct cpumask *m) { return -EINVAL; } -- cgit v1.1 From 4dd53d891ca46dcc1fde0376a33540d3fd83cb9a Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Tue, 21 Dec 2010 17:09:00 -0800 Subject: softirqs: Free up pf flag PF_KSOFTIRQD Cleanup patch, freeing up PF_KSOFTIRQD and use per_cpu ksoftirqd pointer instead, as suggested by Eric Dumazet. Tested-by: Shaun Ruffell Signed-off-by: Venkatesh Pallipadi Signed-off-by: Peter Zijlstra LKML-Reference: <1292980144-28796-2-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar --- include/linux/interrupt.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 55e0d42..a1382b9 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -426,6 +426,13 @@ extern void raise_softirq(unsigned int nr); */ DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list); +DECLARE_PER_CPU(struct task_struct *, ksoftirqd); + +static inline struct task_struct *this_cpu_ksoftirqd(void) +{ + return this_cpu_read(ksoftirqd); +} + /* Try to send a softirq to a remote cpu. If this cannot be done, the * work will be queued to the local cpu. */ -- cgit v1.1 From dc5f219e88294b93009eef946251251ffffb6d60 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 4 Feb 2011 13:19:20 +0100 Subject: genirq: Add IRQF_FORCE_RESUME Xen needs to reenable interrupts which are marked IRQF_NO_SUSPEND in the resume path. Add a flag to force the reenabling in the resume code. Tested-and-acked-by: Ian Campbell Signed-off-by: Thomas Gleixner --- include/linux/interrupt.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 55e0d42..d746da1 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -55,7 +55,7 @@ * Used by threaded interrupts which need to keep the * irq line disabled until the threaded handler has been run. * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend - * + * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set */ #define IRQF_DISABLED 0x00000020 #define IRQF_SAMPLE_RANDOM 0x00000040 @@ -67,6 +67,7 @@ #define IRQF_IRQPOLL 0x00001000 #define IRQF_ONESHOT 0x00002000 #define IRQF_NO_SUSPEND 0x00004000 +#define IRQF_FORCE_RESUME 0x00008000 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND) -- cgit v1.1 From a0cd9ca2b907d7ee26575e7b63ac92dad768a75e Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 10 Feb 2011 11:36:33 +0100 Subject: genirq: Namespace cleanup The irq namespace has become quite convoluted. My bad. Clean it up and deprecate the old functions. All new functions follow the scheme: irq number based: irq_set/get/xxx/_xxx(unsigned int irq, ...) irq_data based: irq_data_set/get/xxx/_xxx(struct irq_data *d, ....) irq_desc based: irq_desc_get_xxx(struct irq_desc *desc) Signed-off-by: Thomas Gleixner --- include/linux/interrupt.h | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 56b7c97..7834726 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -346,16 +346,24 @@ static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long } /* IRQ wakeup (PM) control: */ -extern int set_irq_wake(unsigned int irq, unsigned int on); +extern int irq_set_irq_wake(unsigned int irq, unsigned int on); + +#ifndef CONFIG_GENERIC_HARDIRQS_NO_COMPAT +/* Please do not use: Use the replacement functions instead */ +static inline int set_irq_wake(unsigned int irq, unsigned int on) +{ + return irq_set_irq_wake(irq, on); +} +#endif static inline int enable_irq_wake(unsigned int irq) { - return set_irq_wake(irq, 1); + return irq_set_irq_wake(irq, 1); } static inline int disable_irq_wake(unsigned int irq) { - return set_irq_wake(irq, 0); + return irq_set_irq_wake(irq, 0); } #else /* !CONFIG_GENERIC_HARDIRQS */ -- cgit v1.1 From 1535dfacbf21c4da1b73fcf07c39913da5bd5581 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 7 Feb 2011 01:55:43 +0100 Subject: genirq: Move irq thread flags to core Soleley used in core code. Signed-off-by: Thomas Gleixner --- include/linux/interrupt.h | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 7834726..de97b95 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -74,20 +74,6 @@ #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND) /* - * Bits used by threaded handlers: - * IRQTF_RUNTHREAD - signals that the interrupt handler thread should run - * IRQTF_DIED - handler thread died - * IRQTF_WARNED - warning "IRQ_WAKE_THREAD w/o thread_fn" has been printed - * IRQTF_AFFINITY - irq thread is requested to adjust affinity - */ -enum { - IRQTF_RUNTHREAD, - IRQTF_DIED, - IRQTF_WARNED, - IRQTF_AFFINITY, -}; - -/* * These values can be returned by request_any_context_irq() and * describe the context the interrupt will be run in. * -- cgit v1.1 From c78b9b65faa291def628dbd8539649f58299f0f3 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 16 Dec 2010 17:21:47 +0100 Subject: genirq: Implement generic irq_show_interrupts() All archs implement show_interrupts() in more or less the same way. That's tons of duplicated code with different bugs with no value. Implement a generic version and deprecate show_interrupts() Unfortunately we need some ifdeffery for !GENERIC_HARDIRQ archs. Signed-off-by: Thomas Gleixner --- include/linux/interrupt.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index de97b95..8da6643 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -671,6 +671,7 @@ static inline void init_irq_proc(void) struct seq_file; int show_interrupts(struct seq_file *p, void *v); +int arch_show_interrupts(struct seq_file *p, int prec); extern int early_irq_init(void); extern int arch_probe_nr_irqs(void); -- cgit v1.1 From b5faba21a6805c33b40e258d36f57997ee1de131 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 23 Feb 2011 23:52:13 +0000 Subject: genirq: Prepare the handling of shared oneshot interrupts For level type interrupts we need to track how many threads are on flight to avoid useless interrupt storms when not all thread handlers have finished yet. Keep track of the woken threads and only unmask when there are no more threads in flight. Yes, I'm lazy and using a bitfield. But not only because I'm lazy, the main reason is that it's way simpler than using a refcount. A refcount based solution would need to keep track of various things like crashing the irq thread, spurious interrupts coming in, disables/enables, free_irq() and some more. The bitfield keeps the tracking simple and makes things just work. It's also nicely confined to the thread code pathes and does not require additional checks all over the place. Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra LKML-Reference: <20110223234956.388095876@linutronix.de> --- include/linux/interrupt.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 8da6643..e116fef 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -99,6 +99,7 @@ typedef irqreturn_t (*irq_handler_t)(int, void *); * @thread_fn: interupt handler function for threaded interrupts * @thread: thread pointer for threaded interrupts * @thread_flags: flags related to @thread + * @thread_mask: bitmask for keeping track of @thread activity */ struct irqaction { irq_handler_t handler; @@ -109,6 +110,7 @@ struct irqaction { irq_handler_t thread_fn; struct task_struct *thread; unsigned long thread_flags; + unsigned long thread_mask; const char *name; struct proc_dir_entry *dir; } ____cacheline_internodealigned_in_smp; -- cgit v1.1 From 0c4602ff88d6d6ef0ee6d228ee9acaa6448ff6f5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 23 Feb 2011 23:52:18 +0000 Subject: genirq: Add IRQF_NO_THREAD Some low level interrupts cannot be threaded even when we force thread all interrupt handlers. Add a flag to annotate such interrupts. Add all timer interrupts to this category by default. Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra LKML-Reference: <20110223234956.578893460@linutronix.de> --- include/linux/interrupt.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index e116fef..0fc3eb9 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -58,6 +58,7 @@ * irq line disabled until the threaded handler has been run. * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set + * IRQF_NO_THREAD - Interrupt cannot be threaded */ #define IRQF_DISABLED 0x00000020 #define IRQF_SAMPLE_RANDOM 0x00000040 @@ -70,8 +71,9 @@ #define IRQF_ONESHOT 0x00002000 #define IRQF_NO_SUSPEND 0x00004000 #define IRQF_FORCE_RESUME 0x00008000 +#define IRQF_NO_THREAD 0x00010000 -#define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND) +#define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD) /* * These values can be returned by request_any_context_irq() and -- cgit v1.1 From 8d32a307e4faa8b123dc8a9cd56d1a7525f69ad3 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 23 Feb 2011 23:52:23 +0000 Subject: genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra LKML-Reference: <20110223234956.772668648@linutronix.de> --- include/linux/interrupt.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 0fc3eb9..f8a8af1 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -383,6 +383,13 @@ static inline int disable_irq_wake(unsigned int irq) } #endif /* CONFIG_GENERIC_HARDIRQS */ + +#ifdef CONFIG_IRQ_FORCED_THREADING +extern bool force_irqthreads; +#else +#define force_irqthreads (0) +#endif + #ifndef __ARCH_SET_SOFTIRQ_PENDING #define set_softirq_pending(x) (local_softirq_pending() = (x)) #define or_softirq_pending(x) (local_softirq_pending() |= (x)) -- cgit v1.1