6ecc2d1ca3
If a trace point header defines TRACE_SYSTEM, then it will add the following trace points into that event system. If include/trace/irq_event_types.h has: #define TRACE_SYSTEM irq at the top and #undef TRACE_SYSTEM at the bottom, then a directory "irq" will be created in the /debug/tracing/events directory. Inside that directory will contain the two trace points that are defined in include/trace/irq_event_types.h. Only adding the above to irq and not to sched, we get: # ls /debug/tracing/events/ irq sched_process_exit sched_signal_send sched_wakeup_new sched_kthread_stop sched_process_fork sched_switch sched_kthread_stop_ret sched_process_free sched_wait_task sched_migrate_task sched_process_wait sched_wakeup # ls /debug/tracing/events/irq irq_handler_entry irq_handler_exit If we add #define TRACE_SYSTEM sched to the trace/sched_event_types.h then the rest of the trace events will be put in a sched directory within the events directory. I've been playing with this idea of the subsystem for a while, but recently Tom Zanussi posted some patches to lkml that included this method. Tom's approach was clean and got me to finally put some effort to clean up the event trace points. Thanks to Tom Zanussi for demonstrating how nice the subsystem method is. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
58 lines
1.5 KiB
C
58 lines
1.5 KiB
C
#ifndef _LINUX_KERNEL_TRACE_EVENTS_H
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#define _LINUX_KERNEL_TRACE_EVENTS_H
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#include <linux/debugfs.h>
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#include <linux/ftrace.h>
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#include "trace.h"
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struct ftrace_event_call {
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char *name;
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char *system;
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struct dentry *dir;
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int enabled;
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int (*regfunc)(void);
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void (*unregfunc)(void);
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};
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#undef TPFMT
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#define TPFMT(fmt, args...) fmt "\n", ##args
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#undef TRACE_FORMAT
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#define TRACE_FORMAT(call, proto, args, fmt) \
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static void ftrace_event_##call(proto) \
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{ \
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event_trace_printk(_RET_IP_, "(" #call ") " fmt); \
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} \
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\
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static int ftrace_reg_event_##call(void) \
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{ \
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int ret; \
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\
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ret = register_trace_##call(ftrace_event_##call); \
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if (!ret) \
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pr_info("event trace: Could not activate trace point " \
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"probe to " #call); \
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return ret; \
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} \
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\
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static void ftrace_unreg_event_##call(void) \
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{ \
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unregister_trace_##call(ftrace_event_##call); \
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} \
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\
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static struct ftrace_event_call __used \
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__attribute__((__aligned__(4))) \
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__attribute__((section("_ftrace_events"))) event_##call = { \
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.name = #call, \
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.system = STR(TRACE_SYSTEM), \
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.regfunc = ftrace_reg_event_##call, \
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.unregfunc = ftrace_unreg_event_##call, \
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}
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void event_trace_printk(unsigned long ip, const char *fmt, ...);
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extern struct ftrace_event_call __start_ftrace_events[];
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extern struct ftrace_event_call __stop_ftrace_events[];
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#endif /* _LINUX_KERNEL_TRACE_EVENTS_H */
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