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Message-ID: <4A2396C7.3000700@cn.fujitsu.com>
Date: Mon, 01 Jun 2009 16:52:23 +0800
From: Li Zefan <lizf@...fujitsu.com>
To: Steven Rostedt <rostedt@...dmis.org>,
Frederic Weisbecker <fweisbec@...il.com>
CC: Ingo Molnar <mingo@...e.hu>, LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH] tracing/irq: use softirq_to_name instead of __print_symbolic
| commit c2adae0970ca1db8adb92fb56ae3bcabd916e8bd
| Author: Steven Rostedt <srostedt@...hat.com>
| Date: Wed May 20 19:56:19 2009 -0400
|
| tracing: convert irq events to use __print_symbolic
|
| The recording of the names at trace time is inefficient. This patch
| implements the softirq event recording to only record the vector
| and then use the __print_symbolic interface to print out the names.
|
| [ Impact: faster recording of softirq events ]
It's great to boost recording of softirq events, but why not simply
use softirq_to_name in TP_printk()?
The above commit has 2 flaws:
- we waste memory defining local static struct trace_print_flags array
in each softirq TRACE_EVENT
- if someone adds/removes a softirq, he may not know show_softirq_name()
needs to be updated
Another issue with the above commit, that the output of softirq events
becomes:
X-1701 [000] 1595.220739: softirq_entry: softirq=1 action=TIMER_SOFTIRQ
Compared to the original output:
X-1701 [000] 1595.220739: softirq_entry: softirq=1 action=TIMER
[ Impact: reserve the original output format of softirq events ]
Signed-off-by: Li Zefan <lizf@...fujitsu.com>
---
include/trace/events/irq.h | 17 ++---------------
1 files changed, 2 insertions(+), 15 deletions(-)
diff --git a/include/trace/events/irq.h b/include/trace/events/irq.h
index 683fb36..2ff9998 100644
--- a/include/trace/events/irq.h
+++ b/include/trace/events/irq.h
@@ -7,19 +7,6 @@
#undef TRACE_SYSTEM
#define TRACE_SYSTEM irq
-#define softirq_name(sirq) { sirq, #sirq }
-#define show_softirq_name(val) \
- __print_symbolic(val, \
- softirq_name(HI_SOFTIRQ), \
- softirq_name(TIMER_SOFTIRQ), \
- softirq_name(NET_TX_SOFTIRQ), \
- softirq_name(NET_RX_SOFTIRQ), \
- softirq_name(BLOCK_SOFTIRQ), \
- softirq_name(TASKLET_SOFTIRQ), \
- softirq_name(SCHED_SOFTIRQ), \
- softirq_name(HRTIMER_SOFTIRQ), \
- softirq_name(RCU_SOFTIRQ))
-
/**
* irq_handler_entry - called immediately before the irq action handler
* @irq: irq number
@@ -107,7 +94,7 @@ TRACE_EVENT(softirq_entry,
),
TP_printk("softirq=%d action=%s", __entry->vec,
- show_softirq_name(__entry->vec))
+ softirq_to_name[__entry->vec])
);
/**
@@ -136,7 +123,7 @@ TRACE_EVENT(softirq_exit,
),
TP_printk("softirq=%d action=%s", __entry->vec,
- show_softirq_name(__entry->vec))
+ softirq_to_name[__entry->vec])
);
#endif /* _TRACE_IRQ_H */
--
1.5.4.rc3
--
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