* [PATCH] softirq,tracing: enable to trace softirq raise latency
@ 2009-11-05 7:54 Lai Jiangshan
2009-11-05 14:43 ` Mathieu Desnoyers
2009-11-09 1:58 ` Frederic Weisbecker
0 siblings, 2 replies; 7+ messages in thread
From: Lai Jiangshan @ 2009-11-05 7:54 UTC (permalink / raw)
To: Ingo Molnar, Steven Rostedt, fweisbec
Cc: Xiao Guangrong, Mathieu Desnoyers, linux-kernel, zhaolei,
Xiao Guangrong, Li Zefan, Thomas Gleixner, Jason Baron
Add a tracepoint for tracing when softirq action is raised.
It and the existed tracepoints complete softirq's tracepoints:
softirq_raise, softirq_entry and softirq_exit.
And when this tracepoint is used in combination with
the softirq_entry tracepoint we can determine
the softirq raise latency.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 75f3f00..b368d5d 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -18,6 +18,7 @@
#include <asm/atomic.h>
#include <asm/ptrace.h>
#include <asm/system.h>
+#include <trace/events/irq.h>
/*
* These correspond to the IORESOURCE_IRQ_* defines in
@@ -372,7 +373,13 @@ asmlinkage void do_softirq(void);
asmlinkage void __do_softirq(void);
extern void open_softirq(int nr, void (*action)(struct softirq_action *));
extern void softirq_init(void);
-#define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
+
+static inline void __raise_softirq_irqoff(unsigned int nr)
+{
+ trace_softirq_raise(nr);
+ or_softirq_pending(1UL << nr);
+}
+
extern void raise_softirq_irqoff(unsigned int nr);
extern void raise_softirq(unsigned int nr);
extern void wakeup_softirqd(void);
diff --git a/include/trace/events/irq.h b/include/trace/events/irq.h
index dcfcd44..799af09 100644
--- a/include/trace/events/irq.h
+++ b/include/trace/events/irq.h
@@ -5,7 +5,9 @@
#define _TRACE_IRQ_H
#include <linux/tracepoint.h>
-#include <linux/interrupt.h>
+
+struct irqaction;
+struct softirq_action;
#define softirq_name(sirq) { sirq##_SOFTIRQ, #sirq }
#define show_softirq_name(val) \
@@ -83,6 +85,32 @@ TRACE_EVENT(irq_handler_exit,
);
/**
+ * softirq_raise - called immediately when a softirq is raised
+ * @nr: softirq vector number
+ *
+ * Tracepoint for tracing when softirq action is raised.
+ * Also, when used in combination with the softirq_entry tracepoint
+ * we can determine the softirq raise latency.
+ */
+TRACE_EVENT(softirq_raise,
+
+ TP_PROTO(unsigned int nr),
+
+ TP_ARGS(nr),
+
+ TP_STRUCT__entry(
+ __field( unsigned int, vec )
+ ),
+
+ TP_fast_assign(
+ __entry->vec = nr;
+ ),
+
+ TP_printk("vec=%d [action=%s]", __entry->vec,
+ show_softirq_name(__entry->vec))
+);
+
+/**
* softirq_entry - called immediately before the softirq handler
* @h: pointer to struct softirq_action
* @vec: pointer to first struct softirq_action in softirq_vec array
@@ -100,11 +128,11 @@ TRACE_EVENT(softirq_entry,
TP_ARGS(h, vec),
TP_STRUCT__entry(
- __field( int, vec )
+ __field( unsigned int, vec )
),
TP_fast_assign(
- __entry->vec = (int)(h - vec);
+ __entry->vec = (unsigned int)(h - vec);
),
TP_printk("vec=%d [action=%s]", __entry->vec,
@@ -129,11 +157,11 @@ TRACE_EVENT(softirq_exit,
TP_ARGS(h, vec),
TP_STRUCT__entry(
- __field( int, vec )
+ __field( unsigned int, vec )
),
TP_fast_assign(
- __entry->vec = (int)(h - vec);
+ __entry->vec = (unsigned int)(h - vec);
),
TP_printk("vec=%d [action=%s]", __entry->vec,
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] softirq,tracing: enable to trace softirq raise latency
2009-11-05 7:54 [PATCH] softirq,tracing: enable to trace softirq raise latency Lai Jiangshan
@ 2009-11-05 14:43 ` Mathieu Desnoyers
2009-11-06 1:15 ` Lai Jiangshan
2009-11-09 1:58 ` Frederic Weisbecker
1 sibling, 1 reply; 7+ messages in thread
From: Mathieu Desnoyers @ 2009-11-05 14:43 UTC (permalink / raw)
To: Lai Jiangshan
Cc: Ingo Molnar, Steven Rostedt, fweisbec, Xiao Guangrong,
linux-kernel, zhaolei, Li Zefan, Thomas Gleixner, Jason Baron
* Lai Jiangshan (laijs@cn.fujitsu.com) wrote:
>
> Add a tracepoint for tracing when softirq action is raised.
>
> It and the existed tracepoints complete softirq's tracepoints:
> softirq_raise, softirq_entry and softirq_exit.
>
> And when this tracepoint is used in combination with
> the softirq_entry tracepoint we can determine
> the softirq raise latency.
>
Hi Lai,
It generally looks good, we have a similar instrumentation point in the
LTTng tree, and it's really useful. It's a good idea to instrument
__raise_softirq_irqoff rather than just raise_softirq_irqoff: it
includes the HI/TASKLET and HRTIMER softirqs.
There is just a small comment which should probably also be changed,
please see below, besides that, you have my
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
> ---
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index 75f3f00..b368d5d 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -18,6 +18,7 @@
> #include <asm/atomic.h>
> #include <asm/ptrace.h>
> #include <asm/system.h>
> +#include <trace/events/irq.h>
>
> /*
> * These correspond to the IORESOURCE_IRQ_* defines in
> @@ -372,7 +373,13 @@ asmlinkage void do_softirq(void);
> asmlinkage void __do_softirq(void);
> extern void open_softirq(int nr, void (*action)(struct softirq_action *));
> extern void softirq_init(void);
> -#define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
> +
> +static inline void __raise_softirq_irqoff(unsigned int nr)
> +{
> + trace_softirq_raise(nr);
> + or_softirq_pending(1UL << nr);
> +}
> +
> extern void raise_softirq_irqoff(unsigned int nr);
> extern void raise_softirq(unsigned int nr);
> extern void wakeup_softirqd(void);
> diff --git a/include/trace/events/irq.h b/include/trace/events/irq.h
> index dcfcd44..799af09 100644
> --- a/include/trace/events/irq.h
> +++ b/include/trace/events/irq.h
> @@ -5,7 +5,9 @@
> #define _TRACE_IRQ_H
>
> #include <linux/tracepoint.h>
> -#include <linux/interrupt.h>
> +
> +struct irqaction;
> +struct softirq_action;
>
> #define softirq_name(sirq) { sirq##_SOFTIRQ, #sirq }
> #define show_softirq_name(val) \
> @@ -83,6 +85,32 @@ TRACE_EVENT(irq_handler_exit,
> );
>
> /**
> + * softirq_raise - called immediately when a softirq is raised
> + * @nr: softirq vector number
> + *
> + * Tracepoint for tracing when softirq action is raised.
> + * Also, when used in combination with the softirq_entry tracepoint
> + * we can determine the softirq raise latency.
> + */
> +TRACE_EVENT(softirq_raise,
> +
> + TP_PROTO(unsigned int nr),
> +
> + TP_ARGS(nr),
> +
> + TP_STRUCT__entry(
> + __field( unsigned int, vec )
> + ),
> +
> + TP_fast_assign(
> + __entry->vec = nr;
> + ),
> +
> + TP_printk("vec=%d [action=%s]", __entry->vec,
> + show_softirq_name(__entry->vec))
> +);
> +
> +/**
> * softirq_entry - called immediately before the softirq handler
> * @h: pointer to struct softirq_action
> * @vec: pointer to first struct softirq_action in softirq_vec array
Please change this comment to "@vec: softirq vector number" while you
are at it. The same probably needs to be done for softirq_exit. @vec are
not pointers: these are offsets.
Thanks,
Mathieu
> @@ -100,11 +128,11 @@ TRACE_EVENT(softirq_entry,
> TP_ARGS(h, vec),
>
> TP_STRUCT__entry(
> - __field( int, vec )
> + __field( unsigned int, vec )
> ),
>
> TP_fast_assign(
> - __entry->vec = (int)(h - vec);
> + __entry->vec = (unsigned int)(h - vec);
> ),
>
> TP_printk("vec=%d [action=%s]", __entry->vec,
> @@ -129,11 +157,11 @@ TRACE_EVENT(softirq_exit,
> TP_ARGS(h, vec),
>
> TP_STRUCT__entry(
> - __field( int, vec )
> + __field( unsigned int, vec )
> ),
>
> TP_fast_assign(
> - __entry->vec = (int)(h - vec);
> + __entry->vec = (unsigned int)(h - vec);
> ),
>
> TP_printk("vec=%d [action=%s]", __entry->vec,
>
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] softirq,tracing: enable to trace softirq raise latency
2009-11-05 14:43 ` Mathieu Desnoyers
@ 2009-11-06 1:15 ` Lai Jiangshan
2009-11-06 1:29 ` Mathieu Desnoyers
0 siblings, 1 reply; 7+ messages in thread
From: Lai Jiangshan @ 2009-11-06 1:15 UTC (permalink / raw)
To: Mathieu Desnoyers
Cc: Ingo Molnar, Steven Rostedt, fweisbec, Xiao Guangrong,
linux-kernel, zhaolei, Li Zefan, Thomas Gleixner, Jason Baron
Mathieu Desnoyers wrote:
> * Lai Jiangshan (laijs@cn.fujitsu.com) wrote:
>> Add a tracepoint for tracing when softirq action is raised.
>>
>> It and the existed tracepoints complete softirq's tracepoints:
>> softirq_raise, softirq_entry and softirq_exit.
>>
>> And when this tracepoint is used in combination with
>> the softirq_entry tracepoint we can determine
>> the softirq raise latency.
>>
>
> Hi Lai,
>
> It generally looks good, we have a similar instrumentation point in the
> LTTng tree, and it's really useful. It's a good idea to instrument
> __raise_softirq_irqoff rather than just raise_softirq_irqoff: it
> includes the HI/TASKLET and HRTIMER softirqs.
>
> There is just a small comment which should probably also be changed,
> please see below, besides that, you have my
>
> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
>
>> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
>> ---
>> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
>> index 75f3f00..b368d5d 100644
>> --- a/include/linux/interrupt.h
>> +++ b/include/linux/interrupt.h
>> @@ -18,6 +18,7 @@
>> #include <asm/atomic.h>
>> #include <asm/ptrace.h>
>> #include <asm/system.h>
>> +#include <trace/events/irq.h>
>>
>> /*
>> * These correspond to the IORESOURCE_IRQ_* defines in
>> @@ -372,7 +373,13 @@ asmlinkage void do_softirq(void);
>> asmlinkage void __do_softirq(void);
>> extern void open_softirq(int nr, void (*action)(struct softirq_action *));
>> extern void softirq_init(void);
>> -#define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
>> +
>> +static inline void __raise_softirq_irqoff(unsigned int nr)
>> +{
>> + trace_softirq_raise(nr);
>> + or_softirq_pending(1UL << nr);
>> +}
>> +
>> extern void raise_softirq_irqoff(unsigned int nr);
>> extern void raise_softirq(unsigned int nr);
>> extern void wakeup_softirqd(void);
>> diff --git a/include/trace/events/irq.h b/include/trace/events/irq.h
>> index dcfcd44..799af09 100644
>> --- a/include/trace/events/irq.h
>> +++ b/include/trace/events/irq.h
>> @@ -5,7 +5,9 @@
>> #define _TRACE_IRQ_H
>>
>> #include <linux/tracepoint.h>
>> -#include <linux/interrupt.h>
>> +
>> +struct irqaction;
>> +struct softirq_action;
>>
>> #define softirq_name(sirq) { sirq##_SOFTIRQ, #sirq }
>> #define show_softirq_name(val) \
>> @@ -83,6 +85,32 @@ TRACE_EVENT(irq_handler_exit,
>> );
>>
>> /**
>> + * softirq_raise - called immediately when a softirq is raised
>> + * @nr: softirq vector number
>> + *
>> + * Tracepoint for tracing when softirq action is raised.
>> + * Also, when used in combination with the softirq_entry tracepoint
>> + * we can determine the softirq raise latency.
>> + */
>> +TRACE_EVENT(softirq_raise,
>> +
>> + TP_PROTO(unsigned int nr),
>> +
>> + TP_ARGS(nr),
>> +
>> + TP_STRUCT__entry(
>> + __field( unsigned int, vec )
>> + ),
>> +
>> + TP_fast_assign(
>> + __entry->vec = nr;
>> + ),
>> +
>> + TP_printk("vec=%d [action=%s]", __entry->vec,
>> + show_softirq_name(__entry->vec))
>> +);
>> +
>> +/**
>> * softirq_entry - called immediately before the softirq handler
>> * @h: pointer to struct softirq_action
>> * @vec: pointer to first struct softirq_action in softirq_vec array
>
> Please change this comment to "@vec: softirq vector number" while you
> are at it. The same probably needs to be done for softirq_exit. @vec are
> not pointers: these are offsets.
>
Thank you for you like it and your comment.
@vec are pointers here. it's softirq_vec. Don't need to change
these comments.
Lai
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] softirq,tracing: enable to trace softirq raise latency
2009-11-06 1:15 ` Lai Jiangshan
@ 2009-11-06 1:29 ` Mathieu Desnoyers
0 siblings, 0 replies; 7+ messages in thread
From: Mathieu Desnoyers @ 2009-11-06 1:29 UTC (permalink / raw)
To: Lai Jiangshan
Cc: Ingo Molnar, Steven Rostedt, fweisbec, Xiao Guangrong,
linux-kernel, zhaolei, Li Zefan, Thomas Gleixner, Jason Baron
* Lai Jiangshan (laijs@cn.fujitsu.com) wrote:
> Mathieu Desnoyers wrote:
> > * Lai Jiangshan (laijs@cn.fujitsu.com) wrote:
> >> +/**
> >> * softirq_entry - called immediately before the softirq handler
> >> * @h: pointer to struct softirq_action
> >> * @vec: pointer to first struct softirq_action in softirq_vec array
> >
> > Please change this comment to "@vec: softirq vector number" while you
> > are at it. The same probably needs to be done for softirq_exit. @vec are
> > not pointers: these are offsets.
> >
>
> Thank you for you like it and your comment.
>
> @vec are pointers here. it's softirq_vec. Don't need to change
> these comments.
Ah, yes, you're right. I got confused by looking only at the patch
context.
Thanks,
Mathieu
>
> Lai
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] softirq,tracing: enable to trace softirq raise latency
2009-11-05 7:54 [PATCH] softirq,tracing: enable to trace softirq raise latency Lai Jiangshan
2009-11-05 14:43 ` Mathieu Desnoyers
@ 2009-11-09 1:58 ` Frederic Weisbecker
1 sibling, 0 replies; 7+ messages in thread
From: Frederic Weisbecker @ 2009-11-09 1:58 UTC (permalink / raw)
To: Lai Jiangshan
Cc: Ingo Molnar, Steven Rostedt, Xiao Guangrong, Mathieu Desnoyers,
linux-kernel, zhaolei, Li Zefan, Thomas Gleixner, Jason Baron
On Thu, Nov 05, 2009 at 03:54:55PM +0800, Lai Jiangshan wrote:
>
> Add a tracepoint for tracing when softirq action is raised.
>
> It and the existed tracepoints complete softirq's tracepoints:
> softirq_raise, softirq_entry and softirq_exit.
>
> And when this tracepoint is used in combination with
> the softirq_entry tracepoint we can determine
> the softirq raise latency.
>
> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Looks good!
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH] softirq,tracing: enable to trace softirq raise latency
@ 2009-12-08 8:32 Lai Jiangshan
2009-12-10 8:06 ` Ingo Molnar
0 siblings, 1 reply; 7+ messages in thread
From: Lai Jiangshan @ 2009-12-08 8:32 UTC (permalink / raw)
To: Ingo Molnar; +Cc: Mathieu Desnoyers, Steven Rostedt, Frederic Weisbecker, LKML
Rebase it for the newly codes
Collect Acks(Acked-by Mathieu Desnoyers and Frederic Weisbecker)
From: Lai Jiangshan <laijs@cn.fujitsu.com>
Add a tracepoint for tracing when softirq action is raised.
It and the existed tracepoints complete softirq's tracepoints:
softirq_raise, softirq_entry and softirq_exit.
And when this tracepoint is used in combination with
the softirq_entry tracepoint we can determine
the softirq raise latency.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
---
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 75f3f00..b368d5d 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -18,6 +18,7 @@
#include <asm/atomic.h>
#include <asm/ptrace.h>
#include <asm/system.h>
+#include <trace/events/irq.h>
/*
* These correspond to the IORESOURCE_IRQ_* defines in
@@ -372,7 +373,13 @@ asmlinkage void do_softirq(void);
asmlinkage void __do_softirq(void);
extern void open_softirq(int nr, void (*action)(struct softirq_action *));
extern void softirq_init(void);
-#define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
+
+static inline void __raise_softirq_irqoff(unsigned int nr)
+{
+ trace_softirq_raise(nr);
+ or_softirq_pending(1UL << nr);
+}
+
extern void raise_softirq_irqoff(unsigned int nr);
extern void raise_softirq(unsigned int nr);
extern void wakeup_softirqd(void);
diff --git a/include/trace/events/irq.h b/include/trace/events/irq.h
index 0e4cfb6..7a21fe2 100644
--- a/include/trace/events/irq.h
+++ b/include/trace/events/irq.h
@@ -5,7 +5,9 @@
#define _TRACE_IRQ_H
#include <linux/tracepoint.h>
-#include <linux/interrupt.h>
+
+struct irqaction;
+struct softirq_action;
#define softirq_name(sirq) { sirq##_SOFTIRQ, #sirq }
#define show_softirq_name(val) \
@@ -82,6 +84,32 @@ TRACE_EVENT(irq_handler_exit,
__entry->irq, __entry->ret ? "handled" : "unhandled")
);
+/**
+ * softirq_raise - called immediately when a softirq is raised
+ * @nr: softirq vector number
+ *
+ * Tracepoint for tracing when softirq action is raised.
+ * Also, when used in combination with the softirq_entry tracepoint
+ * we can determine the softirq raise latency.
+ */
+TRACE_EVENT(softirq_raise,
+
+ TP_PROTO(unsigned int nr),
+
+ TP_ARGS(nr),
+
+ TP_STRUCT__entry(
+ __field( unsigned int, vec )
+ ),
+
+ TP_fast_assign(
+ __entry->vec = nr;
+ ),
+
+ TP_printk("vec=%d [action=%s]", __entry->vec,
+ show_softirq_name(__entry->vec))
+);
+
DECLARE_EVENT_CLASS(softirq,
TP_PROTO(struct softirq_action *h, struct softirq_action *vec),
@@ -89,11 +117,11 @@ DECLARE_EVENT_CLASS(softirq,
TP_ARGS(h, vec),
TP_STRUCT__entry(
- __field( int, vec )
+ __field( unsigned int, vec )
),
TP_fast_assign(
- __entry->vec = (int)(h - vec);
+ __entry->vec = (unsigned int)(h - vec);
),
TP_printk("vec=%d [action=%s]", __entry->vec,
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] softirq,tracing: enable to trace softirq raise latency
2009-12-08 8:32 Lai Jiangshan
@ 2009-12-10 8:06 ` Ingo Molnar
0 siblings, 0 replies; 7+ messages in thread
From: Ingo Molnar @ 2009-12-10 8:06 UTC (permalink / raw)
To: Lai Jiangshan
Cc: Mathieu Desnoyers, Steven Rostedt, Frederic Weisbecker, LKML
* Lai Jiangshan <laijs@cn.fujitsu.com> wrote:
> Rebase it for the newly codes
> Collect Acks(Acked-by Mathieu Desnoyers and Frederic Weisbecker)
>
>
> From: Lai Jiangshan <laijs@cn.fujitsu.com>
>
> Add a tracepoint for tracing when softirq action is raised.
>
> It and the existed tracepoints complete softirq's tracepoints:
> softirq_raise, softirq_entry and softirq_exit.
>
> And when this tracepoint is used in combination with
> the softirq_entry tracepoint we can determine
> the softirq raise latency.
>
> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
ok, it would be nice to expose this functionality via some sort of 'perf
trace --irqlatency' (or perhaps a separate 'perf irq record' 'perf irq
trace' tool) so that users/developers can make use of this new event and
that we can check that it works and latencies are correct, etc.
Ingo
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2009-12-10 8:06 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-11-05 7:54 [PATCH] softirq,tracing: enable to trace softirq raise latency Lai Jiangshan
2009-11-05 14:43 ` Mathieu Desnoyers
2009-11-06 1:15 ` Lai Jiangshan
2009-11-06 1:29 ` Mathieu Desnoyers
2009-11-09 1:58 ` Frederic Weisbecker
2009-12-08 8:32 Lai Jiangshan
2009-12-10 8:06 ` Ingo Molnar
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