Commit 39842323 authored by Jason Baron's avatar Jason Baron Committed by Steven Rostedt

tracing: tracepoints for softirq entry/exit - tracepoints

Introduce softirq entry/exit tracepoints. These are useful for
augmenting existing tracers, and to figure out softirq frequencies and
timings.

[
  s/irq_softirq_/softirq_/ for trace point names and
  Fixed printf format in TRACE_FORMAT macro
   - Steven Rostedt
]

LKML-Reference: <20090312183603.GC3352@redhat.com>
Signed-off-by: default avatarJason Baron <jbaron@redhat.com>
Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
parent 5d592b44
...@@ -40,4 +40,16 @@ TRACE_EVENT(irq_handler_exit, ...@@ -40,4 +40,16 @@ TRACE_EVENT(irq_handler_exit,
__entry->irq, __entry->ret ? "handled" : "unhandled") __entry->irq, __entry->ret ? "handled" : "unhandled")
); );
TRACE_FORMAT(softirq_entry,
TP_PROTO(struct softirq_action *h, struct softirq_action *vec),
TP_ARGS(h, vec),
TP_FMT("softirq=%d action=%s", (int)(h - vec), softirq_to_name[h-vec])
);
TRACE_FORMAT(softirq_exit,
TP_PROTO(struct softirq_action *h, struct softirq_action *vec),
TP_ARGS(h, vec),
TP_FMT("softirq=%d action=%s", (int)(h - vec), softirq_to_name[h-vec])
);
#undef TRACE_SYSTEM #undef TRACE_SYSTEM
...@@ -24,6 +24,7 @@ ...@@ -24,6 +24,7 @@
#include <linux/ftrace.h> #include <linux/ftrace.h>
#include <linux/smp.h> #include <linux/smp.h>
#include <linux/tick.h> #include <linux/tick.h>
#include <trace/irq.h>
#include <asm/irq.h> #include <asm/irq.h>
/* /*
...@@ -186,6 +187,9 @@ EXPORT_SYMBOL(local_bh_enable_ip); ...@@ -186,6 +187,9 @@ EXPORT_SYMBOL(local_bh_enable_ip);
*/ */
#define MAX_SOFTIRQ_RESTART 10 #define MAX_SOFTIRQ_RESTART 10
DEFINE_TRACE(softirq_entry);
DEFINE_TRACE(softirq_exit);
asmlinkage void __do_softirq(void) asmlinkage void __do_softirq(void)
{ {
struct softirq_action *h; struct softirq_action *h;
...@@ -212,8 +216,9 @@ asmlinkage void __do_softirq(void) ...@@ -212,8 +216,9 @@ asmlinkage void __do_softirq(void)
if (pending & 1) { if (pending & 1) {
int prev_count = preempt_count(); int prev_count = preempt_count();
trace_softirq_entry(h, softirq_vec);
h->action(h); h->action(h);
trace_softirq_exit(h, softirq_vec);
if (unlikely(prev_count != preempt_count())) { if (unlikely(prev_count != preempt_count())) {
printk(KERN_ERR "huh, entered softirq %td %s %p" printk(KERN_ERR "huh, entered softirq %td %s %p"
"with preempt_count %08x," "with preempt_count %08x,"
......
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