irq: next irq tracking
Subsystems (8)
Hi Thomas,
this pull request contains the next irq prediction as posted for V10
[1] which takes into account all the commments. It is based on top of v4.12-rc5.
As previously discussed the code is not enabled by default, hence compiled out.
The first patch adds the IRQF_TIMER flag to the timers which are percpu in order to discard any timing measurement when the interrupt is coming from a timer.
The second patch adds a circular buffer and the small routine to store the local time when an interrupt occurs. The t-uple <irq,timestamp> are encoded together into a single 64bits as suggested by Nicolas Pitre.
The third patch provides the mathematic to compute the regular intervals. The rational is in changelog and the math is commented in details in the code.
Thanks.
-- Daniel
[1] https://www.spinics.net/lists/kernel/msg2509177.html
The following changes since commit 32c1431eea4881a6b17bd7c639315010aeefa452:
Linux 4.12-rc5 (2017-06-11 16:48:20 -0700)
are available in the git repository at:
http://[email protected]/people/daniel.lezcano/linux.git next-irq/4.13
for you to fetch changes up to 1ed971bc878ede444d10f8a24bc9963938f0b7c6:
irq: Compute the periodic interval for interrupts (2017-06-12 15:06:00 +0200)
----------------------------------------------------------------
Daniel Lezcano (3):
irq: Allow to pass the IRQF_TIMER flag with percpu irq request
irq: Track the interrupt timings
irq: Compute the periodic interval for interrupts
arch/arm/kernel/smp_twd.c | 3 +- drivers/clocksource/arc_timer.c | 4 +-- drivers/clocksource/arm_arch_timer.c | 20 ++++++++----- drivers/clocksource/arm_global_timer.c | 4 +-- drivers/clocksource/exynos_mct.c | 7 +++-- drivers/clocksource/qcom-timer.c | 4 +-- drivers/clocksource/time-armada-370-xp.c | 9 +++--- drivers/clocksource/timer-nps.c | 6 ++-- include/linux/interrupt.h | 17 ++++++++++- kernel/irq/Kconfig | 3 ++ kernel/irq/Makefile | 1 + kernel/irq/handle.c | 2 ++ kernel/irq/internals.h | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/irq/manage.c | 18 +++++++---- kernel/irq/timings.c | 366 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 15 files changed, 536 insertions(+), 31 deletions(-) create mode 100644 kernel/irq/timings.c
Signature · 5 lines
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PATCH v10 1/3 irq: Allow to pass the IRQF_TIMER flag with percpu irq request
In the next changes, we track when the interrupts occur in order to statistically compute when is supposed to happen the next interrupt.
In all the interruptions, it does not make sense to store the timer interrupt occurences and try to predict the next interrupt as when know the expiration time.
The request_irq() has a irq flags parameter and the timer drivers use it to pass the IRQF_TIMER flag, letting us know the interrupt is coming from a timer. Based on this flag, we can discard these interrupts when tracking them.
But, the API request_percpu_irq does not allow to pass a flag, hence specifying if the interrupt type is a timer.
Add a function request_percpu_irq_flags() where we can specify the flags. The request_percpu_irq() function is changed to be a wrapper to request_percpu_irq_flags() passing a zero flag parameter.
Change the timers using request_percpu_irq() to use request_percpu_irq_flags() instead with the IRQF_TIMER flag set.
For now, in order to prevent a misusage of this parameter, only the IRQF_TIMER flag (or zero) is a valid parameter to be passed to the request_percpu_irq_flags() function.
---
Changelog:
V10:
- Drop the change for arch arm virtual timer https://lkml.org/lkml/2017/4/25/184
V9:
- Clarified the patch description
- Fixed EXPORT_SYMBOL_GPL(request_percpu_irq_flags)
--- arch/arm/kernel/smp_twd.c | 3 ++- drivers/clocksource/arc_timer.c | 4 ++-- drivers/clocksource/arm_arch_timer.c | 20 ++++++++++++-------- drivers/clocksource/arm_global_timer.c | 4 ++-- drivers/clocksource/exynos_mct.c | 7 ++++--- drivers/clocksource/qcom-timer.c | 4 ++-- drivers/clocksource/time-armada-370-xp.c | 9 +++++---- drivers/clocksource/timer-nps.c | 6 +++--- include/linux/interrupt.h | 11 ++++++++++- kernel/irq/manage.c | 15 ++++++++++----- 10 files changed, 52 insertions(+), 31 deletions(-)
arch/arm/kernel/smp_twd.c +2 -1
@@ -332,7 +332,8 @@ static int __init twd_local_timer_common_register(struct device_node *np) goto out_free; } - err =request_percpu_irq (twd_ppi, twd_handler,"twd" , twd_evt); + err =request_percpu_irq_flags (twd_ppi, twd_handler,IRQF_TIMER ,"twd" , + twd_evt);if (err) {pr_err ("twd: can't register interrupt %d (%d)\n" , twd_ppi, err); goto out_free;
drivers/clocksource/arc_timer.c +2 -2
@@ -301,8 +301,8 @@ static int __init arc_clockevent_setup(struct device_node *node) }/* Needs apriori irq_set_percpu_devid() done in intc map function */ - ret =request_percpu_irq (arc_timer_irq, timer_irq_handler, -"Timer0 (per-cpu-tick)" , evt); + ret =request_percpu_irq_flags (arc_timer_irq, timer_irq_handler,IRQF_TIMER , +"Timer0 (per-cpu-tick)" , evt);if (ret) {pr_err ("clockevent: unable to request irq\n" );return ret;
drivers/clocksource/arm_arch_timer.c +12 -8
@@ -980,25 +980,29 @@ static int __init arch_timer_register(void) ppi = arch_timer_ppi[arch_timer_uses_ppi];switch (arch_timer_uses_ppi) {case ARCH_TIMER_VIRT_PPI : - err =request_percpu_irq (ppi, arch_timer_handler_virt, -"arch_timer" , arch_timer_evt); + err =request_percpu_irq_flags (ppi, arch_timer_handler_virt, +IRQF_TIMER ,"arch_timer" , + arch_timer_evt);break ;case ARCH_TIMER_PHYS_SECURE_PPI :case ARCH_TIMER_PHYS_NONSECURE_PPI : - err =request_percpu_irq (ppi, arch_timer_handler_phys, -"arch_timer" , arch_timer_evt); + err =request_percpu_irq_flags (ppi, arch_timer_handler_phys, +IRQF_TIMER ,"arch_timer" , + arch_timer_evt);if (!err &&arch_timer_has_nonsecure_ppi ()) { ppi = arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI ]; - err =request_percpu_irq (ppi, arch_timer_handler_phys, -"arch_timer" , arch_timer_evt); + err =request_percpu_irq_flags (ppi, arch_timer_handler_phys, +IRQF_TIMER ,"arch_timer" , + arch_timer_evt);if (err)free_percpu_irq (arch_timer_ppi[ARCH_TIMER_PHYS_SECURE_PPI ], arch_timer_evt); }break ;case ARCH_TIMER_HYP_PPI : - err =request_percpu_irq (ppi, arch_timer_handler_phys, -"arch_timer" , arch_timer_evt); + err =request_percpu_irq_flags (ppi, arch_timer_handler_phys, +IRQF_TIMER ,"arch_timer" , + arch_timer_evt);break ;default :BUG ();
drivers/clocksource/arm_global_timer.c +2 -2
@@ -302,8 +302,8 @@ static int __init global_timer_of_register(struct device_node *np) goto out_clk; } - err =request_percpu_irq (gt_ppi, gt_clockevent_interrupt, -"gt" , gt_evt); + err =request_percpu_irq_flags (gt_ppi, gt_clockevent_interrupt, +IRQF_TIMER ,"gt" , gt_evt);if (err) {pr_warn ("global-timer: can't register interrupt %d (%d)\n" , gt_ppi, err);
drivers/clocksource/exynos_mct.c +4 -3
@@ -524,9 +524,10 @@ static int __init exynos4_timer_resources(struct device_node *np, void __iomem *if (mct_int_type ==MCT_INT_PPI ) { - err =request_percpu_irq (mct_irqs[MCT_L0_IRQ ], - exynos4_mct_tick_isr,"MCT" , - &percpu_mct_tick); + err =request_percpu_irq_flags (mct_irqs[MCT_L0_IRQ ], + exynos4_mct_tick_isr, +IRQF_TIMER ,"MCT" , + &percpu_mct_tick);WARN (err,"MCT: can't request IRQ %d (%d)\n" , mct_irqs[MCT_L0_IRQ ], err); }else {
drivers/clocksource/qcom-timer.c +2 -2
@@ -174,8 +174,8 @@ static int __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq, }if (percpu) - res =request_percpu_irq (irq, msm_timer_interrupt, -"gp_timer" , msm_evt); + res =request_percpu_irq_flags (irq, msm_timer_interrupt, +IRQF_TIMER ,"gp_timer" , msm_evt);if (res) {pr_err ("request_percpu_irq failed\n" );
drivers/clocksource/time-armada-370-xp.c +5 -4
@@ -309,10 +309,11 @@ static int __init armada_370_xp_timer_common_init(struct device_node *np)/* * Setup clockevent timer (interrupt-driven). */ - res =request_percpu_irq (armada_370_xp_clkevt_irq, - armada_370_xp_timer_interrupt, -"armada_370_xp_per_cpu_tick" , - armada_370_xp_evt); + res =request_percpu_irq_flags (armada_370_xp_clkevt_irq, + armada_370_xp_timer_interrupt, +IRQF_TIMER , +"armada_370_xp_per_cpu_tick" , + armada_370_xp_evt);/* Immediately configure the timer on the boot CPU */ if (res) {pr_err ("Failed to request percpu irq\n" );
drivers/clocksource/timer-nps.c +3 -3
@@ -256,9 +256,9 @@ static int __init nps_setup_clockevent(struct device_node *node)return ret;/* Needs apriori irq_set_percpu_devid() done in intc map function */ - ret =request_percpu_irq (nps_timer0_irq, timer_irq_handler, -"Timer0 (per-cpu-tick)" , - &nps_clockevent_device); + ret =request_percpu_irq_flags (nps_timer0_irq, timer_irq_handler, +IRQF_TIMER ,"Timer0 (per-cpu-tick)" , + &nps_clockevent_device);if (ret) {pr_err ("Couldn't request irq\n" );clk_disable_unprepare (clk);
include/linux/interrupt.h +10 -1
@@ -152,8 +152,17 @@ request_any_context_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *name, void *dev_id);extern int __must_check +request_percpu_irq_flags (unsigned int irq,irq_handler_t handler, +unsigned long flags,const char *devname, +void __percpu *percpu_dev_id); + +static inline int __must_check request_percpu_irq (unsigned int irq,irq_handler_t handler, -const char *devname,void __percpu *percpu_dev_id); +const char *devname,void __percpu *percpu_dev_id) +{ +return request_percpu_irq_flags (irq, handler,0 , + devname, percpu_dev_id); +}extern const void *free_irq (unsigned int ,void *);extern void free_percpu_irq (unsigned int ,void __percpu *);
kernel/irq/manage.c +10 -5
@@ -1958,9 +1958,10 @@ int setup_percpu_irq(unsigned int irq, struct irqaction *act) }/** -* request_percpu_irq - allocate a percpu interrupt line +* request_percpu_irq_flags - allocate a percpu interrupt line * @irq: Interrupt line to allocate * @handler: Function to be called when the IRQ occurs. +* @flags: Interrupt type flags (IRQF_TIMER only) * @devname: An ascii name for the claiming device * @dev_id: A percpu cookie passed back to the handler function *
@@ -1973,8 +1974,9 @@ int setup_percpu_irq(unsigned int irq, struct irqaction *act)* the handler gets called with the interrupted CPU's instance of * that variable. */ -int request_percpu_irq (unsigned int irq,irq_handler_t handler, -const char *devname,void __percpu *dev_id) +int request_percpu_irq_flags (unsigned int irq,irq_handler_t handler, +unsigned long flags,const char *devname, +void __percpu *dev_id) {struct irqaction *action;struct irq_desc *desc;
@@ -1988,12 +1990,15 @@ int request_percpu_irq(unsigned int irq, irq_handler_t handler, !irq_settings_is_per_cpu_devid(desc))return -EINVAL ; +if (flags && flags !=IRQF_TIMER ) +return -EINVAL ; + action =kzalloc (sizeof (struct irqaction ),GFP_KERNEL );if (!action)return -ENOMEM ; action->handler = handler; - action->flags =IRQF_PERCPU |IRQF_NO_SUSPEND ; + action->flags = flags |IRQF_PERCPU |IRQF_NO_SUSPEND ; action->name = devname; action->percpu_dev_id = dev_id;
@@ -2014,7 +2019,7 @@ int request_percpu_irq(unsigned int irq, irq_handler_t handler,return retval; } -EXPORT_SYMBOL_GPL (request_percpu_irq); +EXPORT_SYMBOL_GPL (request_percpu_irq_flags);/** * irq_get_irqchip_state - returns the irqchip state of a interrupt.
Signature · 1 line
2.7.4
PATCH v10 2/3 irq: Track the interrupt timings
The interrupt framework gives a lot of information about each interrupt.
It does not keep track of when those interrupts occur though.
This patch provides a mean to record the timestamp for each interrupt occurrences in a per-CPU circular buffer to help with the prediction of the next occurrence using a statistical model.
Each CPU can store IRQ_TIMINGS_SIZE events <irq, timestamp>, the current value of IRQ_TIMINGS_SIZE is 32.
Each event is encoded into a single u64, where the 48 bits are used for the timestamp and the next 16 bits are for the irq number.
A static key is introduced so when the irq prediction is switched off at runtime, we can reduce the overhead near to zero.
It results in most of the code in internals.h for inline reason and a very few in the new file timings.c. The latter will contain more in the next patch which will provide the statistical model for the next event prediction.
Note this code is by default *not* compiled in the kernel.
---
V9:
- Changed indentation level by inverting the static key condition
- Encoded interrupt and timestamp into a u64 variable
- Boolean enable instead of refcount for the static key
V8:
- Replaced percpu field in the irqdesc by a percpu array containing the timings and the associated irq. The function irq_timings_get_next() is no longer needed, so it is removed
- Removed all unused code resulting from the conversion irqdesc->percpu timings storage
V7:
- Mentionned in the irq_timings_get_next() function description, the function must be called inside a rcu read locked section
V6:
- Renamed handle_irq_timings to record_irq_time
- Stored the event time instead of the interval time
- Removed the 'timestamp' field from the timings structure
- Moved _handle_irq_timings content inside record_irq_time
V5:
- Changed comment about 'deterministic' as the comment is confusing
- Added license comment in the header
- Replaced irq_timings_get/put by irq_timings_enable/disable
- Moved IRQS_TIMINGS check in the handle_timings inline function
- Dropped 'if !prev' as it is pointless
- Stored time interval in nsec basis with u64 instead of u32
- Removed redundant store
- Removed the math
V4:
- Added a static key
- Added more comments for irq_timings_get_next()
- Unified some function names to be prefixed by 'irq_timings_...'
- Fixed a rebase error
V3:
- Replaced ktime_get() by local_clock()
- Shared irq are not handled
- Simplified code by adding the timing in the irqdesc struct
- Added a function to browse the irq timings
V2:
- Fixed kerneldoc comment
- Removed data field from the struct irq timing
- Changed the lock section comment
- Removed semi-colon style with empty stub
- Replaced macro by static inline
- Fixed static functions declaration
RFC:
- initial posting
--- include/linux/interrupt.h | 5 +++ kernel/irq/Kconfig | 3 ++ kernel/irq/Makefile | 1 + kernel/irq/handle.c | 2 ++ kernel/irq/internals.h | 84 +++++++++++++++++++++++++++++++++++++++++++++++ kernel/irq/manage.c | 3 ++ kernel/irq/timings.c | 30 +++++++++++++++++ 7 files changed, 128 insertions(+) create mode 100644 kernel/irq/timings.c
include/linux/interrupt.h +5 -0
@@ -712,6 +712,11 @@ static inline void init_irq_proc(void) }#endif +#ifdef CONFIG_IRQ_TIMINGS +void irq_timings_enable (void ); +void irq_timings_disable (void ); +#endif +struct seq_file ;int show_interrupts (struct seq_file *p,void *v);int arch_show_interrupts (struct seq_file *p,int prec);
kernel/irq/Kconfig +3 -0
@@ -81,6 +81,9 @@ config GENERIC_MSI_IRQ_DOMAIN config HANDLE_DOMAIN_IRQ bool +config IRQ_TIMINGS + bool + config IRQ_DOMAIN_DEBUG bool "Expose hardware/virtual IRQ mapping via debugfs" depends on IRQ_DOMAIN && DEBUG_FS
kernel/irq/Makefile +1 -0
@@ -10,3 +10,4 @@ obj-$(CONFIG_PM_SLEEP) += pm.o obj-$(CONFIG_GENERIC_MSI_IRQ) += msi.o obj-$(CONFIG_GENERIC_IRQ_IPI) += ipi.o obj-$(CONFIG_SMP) += affinity.o +obj-$(CONFIG_IRQ_TIMINGS) += timings.o
kernel/irq/handle.c +2 -0
@@ -138,6 +138,8 @@ irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc, unsigned int *flagsunsigned int irq = desc->irq_data.irq;struct irqaction *action; +record_irq_time (desc); +for_each_action_of_desc (desc, action) {irqreturn_t res;
kernel/irq/internals.h +84 -0
99 lines not on this page · raw message
kernel/irq/manage.c +3 -0
@@ -1372,6 +1372,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)raw_spin_unlock_irqrestore (&desc->lock, flags); +setup_timings (desc, new); +/* * Strictly no need to wake it up, but hung_task complains * when no hard interrupt wakes the thread up.
@@ -1500,6 +1502,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)irq_settings_clr_disable_unlazy (desc);irq_shutdown (desc);irq_release_resources (desc); +remove_timings (desc); }#ifdef CONFIG_SMP
kernel/irq/timings.c new file +30 -0
@@ -0,0 +1,30 @@ +/* +* linux/kernel/irq/timings.c +* +* Copyright (C) 2016, Linaro Ltd - Daniel Lezcano <[email protected]> +* +* This program is free software; you can redistribute it and/or modify +* it under the terms of the GNU General Public License version 2 as +* published by the Free Software Foundation. +* +*/ +#include <linux/percpu.h> +#include <linux/static_key.h> +#include <linux/interrupt.h> +#include <linux/irq.h> + +#include "internals.h" + +DEFINE_STATIC_KEY_FALSE (irq_timing_enabled); + +DEFINE_PER_CPU(struct irq_timings, irq_timings); + +void irq_timings_enable (void ) +{ +static_branch_enable (&irq_timing_enabled); +} + +void irq_timings_disable (void ) +{ +static_branch_disable (&irq_timing_enabled); +}
Signature · 1 line
2.7.4
PATCH v10 3/3 irq: Compute the periodic interval for interrupts
In reply to Daniel LezcanoAn interrupt behaves with a burst of activity with periodic interval of time followed by one or two peaks of longer interval.
As the time intervals are periodic, statistically speaking they follow a normal distribution and each interrupts can be tracked individually.
This patch does statistics on all interrupts, except the timers which are deterministic by essence. The goal is to extract the periodicity for each interrupt, with the last timestamp and sum them, so we have the next event.
Taking the earliest prediction gives the expected wakeup on the system (assuming a timer won't expire before).
As stated in the previous patch, this code is not enabled in the kernel by default.
---
Changelog:
V10:
- Simplified index/count computation
V9:
- Deal with 48+16 bits encoded values
- Changed irq_stat => irqt_stat to prevent name collision on s390
- Changed div64 by constant IRQ_TIMINGS_SHIFT bit shift for average
- Changed div64 by constant IRQ_TIMINGS_SHIFT bit shift for variance
--- include/linux/interrupt.h | 1 + kernel/irq/internals.h | 21 ++- kernel/irq/timings.c | 336 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 357 insertions(+), 1 deletion(-)
include/linux/interrupt.h +1 -0
@@ -715,6 +715,7 @@ static inline void init_irq_proc(void)#ifdef CONFIG_IRQ_TIMINGS void irq_timings_enable (void );void irq_timings_disable (void ); +u64 irq_timings_next_event (u64 now);#endif struct seq_file ;
kernel/irq/internals.h +20 -1
@@ -237,18 +237,26 @@ irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action) { }struct irq_timings {u64 values[IRQ_TIMINGS_SIZE ];/* our circular buffer */ -unsigned int count;/* Number of interruptions since last inspection */ +int count;/* Number of interruptions since last inspection */ }; DECLARE_PER_CPU(struct irq_timings, irq_timings); +extern void irq_timings_free (int irq); +extern int irq_timings_alloc (int irq); +static inline void remove_timings (struct irq_desc *desc) { desc->istate &= ~IRQS_TIMINGS ; + +irq_timings_free (irq_desc_get_irq (desc)); }static inline void setup_timings (struct irq_desc *desc,struct irqaction *act) { +int irq =irq_desc_get_irq (desc); +int ret; +/* * We don't need the measurement because the idle code already * knows the next expiry event.
@@ -256,6 +264,17 @@ static inline void setup_timings(struct irq_desc *desc, struct irqaction *act)if (act->flags & __IRQF_TIMER)return ; +/* +* In case the timing allocation fails, we just want to warn, +* not fail, so letting the system boot anyway. +*/ + ret =irq_timings_alloc (irq); +if (ret) { +pr_warn ("Failed to allocate irq timing stats for irq%d (%d)" , + irq, ret); +return ; + } + desc->istate |=IRQS_TIMINGS ; }
kernel/irq/timings.c +336 -0
355 lines not on this page · raw message
Signature · 1 line
2.7.4
Re: [PATCH V10 1/3] irq: Allow to pass the IRQF_TIMER flag with percpu irq request
In reply to Daniel LezcanoQuoted 6 lines · Daniel Lezcano
But, the API
request_percpu_irqdoes not allow to pass a flag, hence specifying if the interrupt type is a timer.Add a function
request_percpu_irq_flags()where we can specify the flags. Therequest_percpu_irq()function is changed to be a wrapper torequest_percpu_irq_flags()passing a zero flag parameter.
And exactly this change wants to be a separate patch. We do not make whole sale changes this way. You should know that already and someone pointed that out to you in some of the earlier versions.
kernel/irq/manage.c int setup_percpu_irq(unsigned int irq, struct irqaction *act) · line 1977
Quoted 3 lines
kernel/irq/manage.c +1
-2-int request_percpu_irq (unsigned int irq,irq_handler_t handler, -const char *devname,void __percpu *dev_id) +int request_percpu_irq_flags(unsigned int irq, irq_handler_t handler,
The function name sucks. The first time I read it, it meant request the per cpu irq flags, which is not what you aim at, right?
Please make that __request_percpu_irq() for now and on -rc1 time provide a patch set to convert all current request_percpu_irq() users to have the extra argument and then remove the __request_percpu_irq() intermediate.
Thanks,
tglx
Re: [PATCH V10 1/3] irq: Allow to pass the IRQF_TIMER flag with percpu irq request
Quoted 19 lines · Thomas Gleixner
Quoted 6 lines · Daniel Lezcano
But, the API
request_percpu_irqdoes not allow to pass a flag, hence specifying if the interrupt type is a timer.Add a function
request_percpu_irq_flags()where we can specify the flags. Therequest_percpu_irq()function is changed to be a wrapper torequest_percpu_irq_flags()passing a zero flag parameter.And exactly this change wants to be a separate patch. We do not make whole sale changes this way. You should know that already and someone pointed that out to you in some of the earlier versions.
kernel/irq/manage.c int setup_percpu_irq(unsigned int irq, struct irqaction *act) · line 1977
Quoted 3 lines
kernel/irq/manage.c +1
-2-int request_percpu_irq (unsigned int irq,irq_handler_t handler, -const char *devname,void __percpu *dev_id) +int request_percpu_irq_flags(unsigned int irq, irq_handler_t handler,The function name sucks. The first time I read it, it meant request the per cpu irq flags, which is not what you aim at, right?
Quoted 3 lines
Please make that
__request_percpu_irq()for now and on -rc1 time provide a patch set to convert all currentrequest_percpu_irq()users to have the extra argument and then remove the__request_percpu_irq()intermediate.
Ok, I will the change this way.
What about 2/3 and 3/3? Is it possible to take them with the __request_percpu_irq change?
Signature · 5 lines
<http://www.linaro.org/> Linaro.org ? Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog
Re: [PATCH V10 1/3] irq: Allow to pass the IRQF_TIMER flag with percpu irq request
Quoted 20 lines · Daniel Lezcano
Quoted 19 lines · Thomas Gleixner
Quoted 6 lines · Daniel Lezcano
But, the API
request_percpu_irqdoes not allow to pass a flag, hence specifying if the interrupt type is a timer.Add a function
request_percpu_irq_flags()where we can specify the flags. Therequest_percpu_irq()function is changed to be a wrapper torequest_percpu_irq_flags()passing a zero flag parameter.And exactly this change wants to be a separate patch. We do not make whole sale changes this way. You should know that already and someone pointed that out to you in some of the earlier versions.
kernel/irq/manage.c int setup_percpu_irq(unsigned int irq, struct irqaction *act) · line 1977
Quoted 3 lines
kernel/irq/manage.c +1
-2-int request_percpu_irq (unsigned int irq,irq_handler_t handler, -const char *devname,void __percpu *dev_id) +int request_percpu_irq_flags(unsigned int irq, irq_handler_t handler,The function name sucks. The first time I read it, it meant request the per cpu irq flags, which is not what you aim at, right?
Quoted 8 lines
Quoted 3 lines
Please make that
__request_percpu_irq()for now and on -rc1 time provide a patch set to convert all currentrequest_percpu_irq()users to have the extra argument and then remove the__request_percpu_irq()intermediate.Ok, I will the change this way.
What about 2/3 and 3/3? Is it possible to take them with the
__request_percpu_irqchange?
The rest looks ok. Please repost.
Re: [PATCH V10 1/3] irq: Allow to pass the IRQF_TIMER flag with percpu irq request
Quoted 25 lines · Thomas Gleixner
Quoted 24 lines · Daniel Lezcano
Quoted 22 lines · Thomas Gleixner
Quoted 6 lines · Daniel Lezcano
But, the API
request_percpu_irqdoes not allow to pass a flag, hence specifying if the interrupt type is a timer.Add a function
request_percpu_irq_flags()where we can specify the flags. Therequest_percpu_irq()function is changed to be a wrapper torequest_percpu_irq_flags()passing a zero flag parameter.And exactly this change wants to be a separate patch. We do not make whole sale changes this way. You should know that already and someone pointed that out to you in some of the earlier versions.
kernel/irq/manage.c int setup_percpu_irq(unsigned int irq, struct irqaction *act) · line 1977
Quoted 3 lines
kernel/irq/manage.c +1
-2-int request_percpu_irq (unsigned int irq,irq_handler_t handler, -const char *devname,void __percpu *dev_id) +int request_percpu_irq_flags(unsigned int irq, irq_handler_t handler,The function name sucks. The first time I read it, it meant request the per cpu irq flags, which is not what you aim at, right?
Please make that
__request_percpu_irq()for now and on -rc1 time provide a patch set to convert all currentrequest_percpu_irq()users to have the extra argument and then remove the__request_percpu_irq()intermediate.
Quoted 6 lines
Quoted 4 lines
Ok, I will the change this way.
What about 2/3 and 3/3? Is it possible to take them with the
__request_percpu_irqchange?The rest looks ok. Please repost.
Ok, thanks.
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Hi,
this series has been posted several times and all the comments have been take into account.
Can you clarify the situation with this series regarding merging?
Thanks.
-- Daniel
Quoted 62 lines · Daniel Lezcano
Hi Thomas,
this pull request contains the next irq prediction as posted for V10
[1] which takes into account all the commments. It is based on top of v4.12-rc5.As previously discussed the code is not enabled by default, hence compiled out.
The first patch adds the
IRQF_TIMERflag to the timers which are percpu in order to discard any timing measurement when the interrupt is coming from a timer.The second patch adds a circular buffer and the small routine to store the local time when an interrupt occurs. The t-uple <irq,timestamp> are encoded together into a single 64bits as suggested by Nicolas Pitre.
The third patch provides the mathematic to compute the regular intervals. The rational is in changelog and the math is commented in details in the code.
Thanks.
-- Daniel
[1] https://www.spinics.net/lists/kernel/msg2509177.html
The following changes since commit
32c1431eea4881a6b17bd7c639315010aeefa452:Linux 4.12-rc5 (2017-06-11 16:48:20 -0700)
are available in the git repository at:
http://[email protected]/people/daniel.lezcano/linux.git next-irq/4.13
for you to fetch changes up to
1ed971bc878ede444d10f8a24bc9963938f0b7c6:irq: Compute the periodic interval for interrupts (2017-06-12 15:06:00 +0200)
----------------------------------------------------------------
Daniel Lezcano (3):
irq: Allow to pass theIRQF_TIMERflag with percpu irq request
irq: Track the interrupt timings
irq: Compute the periodic interval for interruptsarch/arm/kernel/smp_twd.c | 3 +- drivers/clocksource/arc_timer.c | 4 +-- drivers/clocksource/arm_arch_timer.c | 20 ++++++++----- drivers/clocksource/arm_global_timer.c | 4 +-- drivers/clocksource/exynos_mct.c | 7 +++-- drivers/clocksource/qcom-timer.c | 4 +-- drivers/clocksource/time-armada-370-xp.c | 9 +++--- drivers/clocksource/timer-nps.c | 6 ++-- include/linux/interrupt.h | 17 ++++++++++- kernel/irq/Kconfig | 3 ++ kernel/irq/Makefile | 1 + kernel/irq/handle.c | 2 ++ kernel/irq/internals.h | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/irq/manage.c | 18 +++++++---- kernel/irq/timings.c | 366 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 15 files changed, 536 insertions(+), 31 deletions(-) create mode 100644 kernel/irq/timings.c
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