[PATCH V4] trace/events: add chip name and hwirq to irq entry tracepoint

From: Ankit Gupta
Date: Wed Jul 08 2015 - 18:26:25 EST


Add chip name and hw-irq number to the trace_irq_handler_entry()
tracepoint. When tracing interrupt events the chip-name and hw-irq
numbers are stable and known in advance. This makes them a better
choice as a filtering criteria for the trace buffer dump. On the
flipside, the os-irq numbers are dynamically allocated which makes
them difficult to use for the same purpose.

Dump messages will look like:
...irq_handler_entry: irq=22 name=msm_serial0 chip_name=GIC hwirq=140

Suggested-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Reviewed-by: Andy Gross <agross@xxxxxxxxxxxxxx>
Signed-off-by: Gilad Avidov <gavidov@xxxxxxxxxxxxxx>
Signed-off-by: Ankit Gupta <ankgupta@xxxxxxxxxxxxxx>
---
Changes since V3:
- use field variable in trace structure to assign value for chip name
and hwirq rather than printing directly to the trace buffer.
---
Changes since V2:
- fixed dump message in commit text to reflect Chip name
instead of domain.
---
Changes since V1:
- added reviewed by Andy Gross
---
include/trace/events/irq.h | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/include/trace/events/irq.h b/include/trace/events/irq.h
index 3608beb..0898506 100644
--- a/include/trace/events/irq.h
+++ b/include/trace/events/irq.h
@@ -23,6 +23,17 @@ struct softirq_action;
softirq_name(HRTIMER), \
softirq_name(RCU))

+
+#define show_chip_name(irq) \
+ (irq_get_irq_data(irq) \
+ ? irq_get_irq_data(irq)->chip->name \
+ : "NULL")
+
+#define show_hwirq(irq) \
+ (irq_get_irq_data(irq) \
+ ? irq_get_irq_data(irq)->hwirq \
+ : -ENODEV)
+
/**
* irq_handler_entry - called immediately before the irq action handler
* @irq: irq number
@@ -41,16 +52,21 @@ TRACE_EVENT(irq_handler_entry,
TP_ARGS(irq, action),

TP_STRUCT__entry(
- __field( int, irq )
- __string( name, action->name )
+ __field( int, irq )
+ __field( unsigned long, hwirq )
+ __string( name, action->name )
+ __string( chip, show_chip_name(irq) )
),

TP_fast_assign(
__entry->irq = irq;
+ __entry->hwirq = show_hwirq(irq);
__assign_str(name, action->name);
+ __assign_str(chip, show_chip_name(irq));
),

- TP_printk("irq=%d name=%s", __entry->irq, __get_str(name))
+ TP_printk("irq=%d name=%s chip=%s hwirq=%ld", __entry->irq,
+ __get_str(name), __get_str(chip), __entry->hwirq)
);

/**
--
1.8.5.2

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