This patch adds a tracepoint to raising of softirq.
This is useful if you want to detect which hard interrupt raise softirq
and lets you know a time between raising softirq and performing softirq.
Combinating with other tracepoint, it lets us know a process of packets
(See patch 0/5).
<idle>-0 [001] 241229.957184: softirq_raise: vec=3 [action=NET_RX]
<idle>-0 [000] 241229.993399: softirq_raise: vec=1 [action=TIMER]
<idle>-0 [000] 241229.993400: softirq_raise: vec=9 [action=RCU]
This is a same patch Lai Jiangshan submitted.
http://marc.info/?l=linux-kernel&m=126026122728732&w=2
Signed-off-by: Koki Sanagi <[email protected]>
---
include/linux/interrupt.h | 8 +++++++-
include/trace/events/irq.h | 34 +++++++++++++++++++++++++++++++---
2 files changed, 38 insertions(+), 4 deletions(-)
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index c233113..1cb5726 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
@@ -402,7 +403,12 @@ 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..7cb7435 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,
(cc to Lai)
> This patch adds a tracepoint to raising of softirq.
> This is useful if you want to detect which hard interrupt raise softirq
> and lets you know a time between raising softirq and performing softirq.
> Combinating with other tracepoint, it lets us know a process of packets
> (See patch 0/5).
>
> <idle>-0 [001] 241229.957184: softirq_raise: vec=3 [action=NET_RX]
> <idle>-0 [000] 241229.993399: softirq_raise: vec=1 [action=TIMER]
> <idle>-0 [000] 241229.993400: softirq_raise: vec=9 [action=RCU]
>
> This is a same patch Lai Jiangshan submitted.
> http://marc.info/?l=linux-kernel&m=126026122728732&w=2
If so, you shouldn't remove author's info. please fix the description
as following.
-------------------------------------------------------------------------
From: Lai Jiangshan <[email protected]>
This patch adds a tracepoint to raising of softirq.
This is useful if you want to detect which hard interrupt raise softirq
and lets you know a time between raising softirq and performing softirq.
Combinating with other tracepoint, it lets us know a process of packets
(See patch 0/5).
<idle>-0 [001] 241229.957184: softirq_raise: vec=3 [action=NET_RX]
<idle>-0 [000] 241229.993399: softirq_raise: vec=1 [action=TIMER]
<idle>-0 [000] 241229.993400: softirq_raise: vec=9 [action=RCU]
This is a same below.
http://marc.info/?l=linux-kernel&m=126026122728732&w=2
Signed-off-by: Lai Jiangshan <[email protected]>
Acked-by: Mathieu Desnoyers <[email protected]>
Acked-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Koki Sanagi <[email protected]>
--------------------------------------------------------------------------------
Thanks Kosaki,
I'll fix a description.
(2010/06/25 10:10), KOSAKI Motohiro wrote:
> (cc to Lai)
>
>> This patch adds a tracepoint to raising of softirq.
>> This is useful if you want to detect which hard interrupt raise softirq
>> and lets you know a time between raising softirq and performing softirq.
>> Combinating with other tracepoint, it lets us know a process of packets
>> (See patch 0/5).
>>
>> <idle>-0 [001] 241229.957184: softirq_raise: vec=3 [action=NET_RX]
>> <idle>-0 [000] 241229.993399: softirq_raise: vec=1 [action=TIMER]
>> <idle>-0 [000] 241229.993400: softirq_raise: vec=9 [action=RCU]
>>
>> This is a same patch Lai Jiangshan submitted.
>> http://marc.info/?l=linux-kernel&m=126026122728732&w=2
>
> If so, you shouldn't remove author's info. please fix the description
> as following.
>
> -------------------------------------------------------------------------
> From: Lai Jiangshan <[email protected]>
>
> This patch adds a tracepoint to raising of softirq.
> This is useful if you want to detect which hard interrupt raise softirq
> and lets you know a time between raising softirq and performing softirq.
> Combinating with other tracepoint, it lets us know a process of packets
> (See patch 0/5).
>
> <idle>-0 [001] 241229.957184: softirq_raise: vec=3 [action=NET_RX]
> <idle>-0 [000] 241229.993399: softirq_raise: vec=1 [action=TIMER]
> <idle>-0 [000] 241229.993400: softirq_raise: vec=9 [action=RCU]
>
> This is a same below.
> http://marc.info/?l=linux-kernel&m=126026122728732&w=2
>
> Signed-off-by: Lai Jiangshan <[email protected]>
> Acked-by: Mathieu Desnoyers <[email protected]>
> Acked-by: Frederic Weisbecker <[email protected]>
> Signed-off-by: Koki Sanagi <[email protected]>
> --------------------------------------------------------------------------------
>
>
>
>
2010/6/25 KOSAKI Motohiro <[email protected]>:
> (cc to Lai)
>
>> This patch adds a tracepoint to raising of softirq.
>> This is useful if you want to detect which hard interrupt raise softirq
>> and lets you know a time between raising softirq and performing softirq.
>> Combinating with other tracepoint, it lets us know a process of packets
>> (See patch 0/5).
>>
>> ? ? ? ? ? <idle>-0 ? ? [001] 241229.957184: softirq_raise: vec=3 [action=NET_RX]
>> ? ? ? ? ? <idle>-0 ? ? [000] 241229.993399: softirq_raise: vec=1 [action=TIMER]
>> ? ? ? ? ? <idle>-0 ? ? [000] 241229.993400: softirq_raise: vec=9 [action=RCU]
>>
>> This is a same patch Lai Jiangshan submitted.
>> http://marc.info/?l=linux-kernel&m=126026122728732&w=2
>
> If so, you shouldn't remove author's info. please fix the description
> as following.
>
> -------------------------------------------------------------------------
> From: Lai Jiangshan <[email protected]>
>
> This patch adds a tracepoint to raising of softirq.
> This is useful if you want to detect which hard interrupt raise softirq
> and lets you know a time between raising softirq and performing softirq.
> Combinating with other tracepoint, it lets us know a process of packets
> (See patch 0/5).
>
> ? ? ? ? ?<idle>-0 ? ? [001] 241229.957184: softirq_raise: vec=3 [action=NET_RX]
> ? ? ? ? ?<idle>-0 ? ? [000] 241229.993399: softirq_raise: vec=1 [action=TIMER]
> ? ? ? ? ?<idle>-0 ? ? [000] 241229.993400: softirq_raise: vec=9 [action=RCU]
>
> This is a same below.
> http://marc.info/?l=linux-kernel&m=126026122728732&w=2
>
> Signed-off-by: Lai Jiangshan <[email protected]>
> Acked-by: Mathieu Desnoyers <[email protected]>
> Acked-by: Frederic Weisbecker <[email protected]>
Right. And if you do some changes in the original patch, you can just
change the description, or add a simple line before your Signed-off-by, that
says:
[ factorize softirq events with DECLARE_EVENT_CLASS ]
Because indeed, as Steve said, the softirq_raise tracepoint should
belong to the softirq event class as it perfectly matches it. This
helps the kernel
saving some space.
Thanks.
> Signed-off-by: Koki Sanagi <[email protected]>
> --------------------------------------------------------------------------------
>
>
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