ea20d9293c
Impact: clean up Neil Horman (et. al.) criticized the way the trace events were broken up into two files. The reason for that was that ftrace needed to separate out the declarations from where the #include <linux/tracepoint.h> was used. It then dawned on me that the tracepoint.h header only needs to define the TRACE_EVENT macro if it is not already defined. The solution is simply to test if TRACE_EVENT is defined, and if it is not then the linux/tracepoint.h header can define it. This change consolidates all the <traces>.h and <traces>_event_types.h into the <traces>.h file. Reported-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Theodore Tso <tytso@mit.edu> Reported-by: Jiaying Zhang <jiayingz@google.com> Cc: Zhaolei <zhaolei@cn.fujitsu.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
273 lines
7.9 KiB
C
273 lines
7.9 KiB
C
#ifndef _LINUX_TRACEPOINT_H
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#define _LINUX_TRACEPOINT_H
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/*
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* Kernel Tracepoint API.
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*
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* See Documentation/tracepoint.txt.
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*
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* (C) Copyright 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
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*
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* Heavily inspired from the Linux Kernel Markers.
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*
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* This file is released under the GPLv2.
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* See the file COPYING for more details.
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*/
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#include <linux/types.h>
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#include <linux/rcupdate.h>
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struct module;
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struct tracepoint;
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struct tracepoint {
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const char *name; /* Tracepoint name */
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int state; /* State. */
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void **funcs;
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} __attribute__((aligned(32))); /*
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* Aligned on 32 bytes because it is
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* globally visible and gcc happily
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* align these on the structure size.
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* Keep in sync with vmlinux.lds.h.
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*/
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#ifndef DECLARE_TRACE
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#define TP_PROTO(args...) args
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#define TP_ARGS(args...) args
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#ifdef CONFIG_TRACEPOINTS
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/*
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* it_func[0] is never NULL because there is at least one element in the array
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* when the array itself is non NULL.
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*/
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#define __DO_TRACE(tp, proto, args) \
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do { \
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void **it_func; \
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\
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rcu_read_lock_sched_notrace(); \
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it_func = rcu_dereference((tp)->funcs); \
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if (it_func) { \
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do { \
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((void(*)(proto))(*it_func))(args); \
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} while (*(++it_func)); \
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} \
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rcu_read_unlock_sched_notrace(); \
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} while (0)
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/*
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* Make sure the alignment of the structure in the __tracepoints section will
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* not add unwanted padding between the beginning of the section and the
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* structure. Force alignment to the same alignment as the section start.
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*/
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#define DECLARE_TRACE(name, proto, args) \
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extern struct tracepoint __tracepoint_##name; \
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static inline void trace_##name(proto) \
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{ \
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if (unlikely(__tracepoint_##name.state)) \
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__DO_TRACE(&__tracepoint_##name, \
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TP_PROTO(proto), TP_ARGS(args)); \
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} \
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static inline int register_trace_##name(void (*probe)(proto)) \
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{ \
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return tracepoint_probe_register(#name, (void *)probe); \
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} \
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static inline int unregister_trace_##name(void (*probe)(proto)) \
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{ \
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return tracepoint_probe_unregister(#name, (void *)probe);\
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}
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#define DEFINE_TRACE(name) \
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static const char __tpstrtab_##name[] \
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__attribute__((section("__tracepoints_strings"))) = #name; \
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struct tracepoint __tracepoint_##name \
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__attribute__((section("__tracepoints"), aligned(32))) = \
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{ __tpstrtab_##name, 0, NULL }
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#define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \
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EXPORT_SYMBOL_GPL(__tracepoint_##name)
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#define EXPORT_TRACEPOINT_SYMBOL(name) \
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EXPORT_SYMBOL(__tracepoint_##name)
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extern void tracepoint_update_probe_range(struct tracepoint *begin,
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struct tracepoint *end);
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#else /* !CONFIG_TRACEPOINTS */
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#define DECLARE_TRACE(name, proto, args) \
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static inline void _do_trace_##name(struct tracepoint *tp, proto) \
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{ } \
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static inline void trace_##name(proto) \
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{ } \
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static inline int register_trace_##name(void (*probe)(proto)) \
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{ \
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return -ENOSYS; \
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} \
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static inline int unregister_trace_##name(void (*probe)(proto)) \
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{ \
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return -ENOSYS; \
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}
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#define DEFINE_TRACE(name)
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#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
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#define EXPORT_TRACEPOINT_SYMBOL(name)
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static inline void tracepoint_update_probe_range(struct tracepoint *begin,
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struct tracepoint *end)
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{ }
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#endif /* CONFIG_TRACEPOINTS */
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#endif /* DECLARE_TRACE */
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/*
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* Connect a probe to a tracepoint.
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* Internal API, should not be used directly.
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*/
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extern int tracepoint_probe_register(const char *name, void *probe);
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/*
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* Disconnect a probe from a tracepoint.
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* Internal API, should not be used directly.
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*/
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extern int tracepoint_probe_unregister(const char *name, void *probe);
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extern int tracepoint_probe_register_noupdate(const char *name, void *probe);
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extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe);
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extern void tracepoint_probe_update_all(void);
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struct tracepoint_iter {
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struct module *module;
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struct tracepoint *tracepoint;
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};
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extern void tracepoint_iter_start(struct tracepoint_iter *iter);
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extern void tracepoint_iter_next(struct tracepoint_iter *iter);
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extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
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extern void tracepoint_iter_reset(struct tracepoint_iter *iter);
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extern int tracepoint_get_iter_range(struct tracepoint **tracepoint,
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struct tracepoint *begin, struct tracepoint *end);
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/*
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* tracepoint_synchronize_unregister must be called between the last tracepoint
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* probe unregistration and the end of module exit to make sure there is no
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* caller executing a probe when it is freed.
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*/
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static inline void tracepoint_synchronize_unregister(void)
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{
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synchronize_sched();
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}
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#define PARAMS(args...) args
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#ifndef TRACE_FORMAT
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#define TRACE_FORMAT(name, proto, args, fmt) \
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DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
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#endif
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#ifndef TRACE_EVENT
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/*
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* For use with the TRACE_EVENT macro:
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*
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* We define a tracepoint, its arguments, its printk format
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* and its 'fast binay record' layout.
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*
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* Firstly, name your tracepoint via TRACE_EVENT(name : the
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* 'subsystem_event' notation is fine.
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*
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* Think about this whole construct as the
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* 'trace_sched_switch() function' from now on.
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*
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*
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* TRACE_EVENT(sched_switch,
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*
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* *
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* * A function has a regular function arguments
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* * prototype, declare it via TP_PROTO():
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* *
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*
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* TP_PROTO(struct rq *rq, struct task_struct *prev,
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* struct task_struct *next),
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*
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* *
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* * Define the call signature of the 'function'.
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* * (Design sidenote: we use this instead of a
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* * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
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* *
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*
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* TP_ARGS(rq, prev, next),
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*
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* *
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* * Fast binary tracing: define the trace record via
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* * TP_STRUCT__entry(). You can think about it like a
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* * regular C structure local variable definition.
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* *
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* * This is how the trace record is structured and will
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* * be saved into the ring buffer. These are the fields
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* * that will be exposed to user-space in
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* * /debug/tracing/events/<*>/format.
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* *
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* * The declared 'local variable' is called '__entry'
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* *
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* * __field(pid_t, prev_prid) is equivalent to a standard declariton:
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* *
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* * pid_t prev_pid;
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* *
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* * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
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* *
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* * char prev_comm[TASK_COMM_LEN];
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* *
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*
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* TP_STRUCT__entry(
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* __array( char, prev_comm, TASK_COMM_LEN )
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* __field( pid_t, prev_pid )
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* __field( int, prev_prio )
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* __array( char, next_comm, TASK_COMM_LEN )
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* __field( pid_t, next_pid )
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* __field( int, next_prio )
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* ),
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*
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* *
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* * Assign the entry into the trace record, by embedding
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* * a full C statement block into TP_fast_assign(). You
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* * can refer to the trace record as '__entry' -
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* * otherwise you can put arbitrary C code in here.
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* *
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* * Note: this C code will execute every time a trace event
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* * happens, on an active tracepoint.
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* *
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*
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* TP_fast_assign(
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* memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
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* __entry->prev_pid = prev->pid;
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* __entry->prev_prio = prev->prio;
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* memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
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* __entry->next_pid = next->pid;
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* __entry->next_prio = next->prio;
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* )
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*
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* *
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* * Formatted output of a trace record via TP_printk().
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* * This is how the tracepoint will appear under ftrace
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* * plugins that make use of this tracepoint.
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* *
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* * (raw-binary tracing wont actually perform this step.)
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* *
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*
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* TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
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* __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
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* __entry->next_comm, __entry->next_pid, __entry->next_prio),
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*
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* );
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*
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* This macro construct is thus used for the regular printk format
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* tracing setup, it is used to construct a function pointer based
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* tracepoint callback (this is used by programmatic plugins and
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* can also by used by generic instrumentation like SystemTap), and
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* it is also used to expose a structured trace record in
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* /debug/tracing/events/.
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*/
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#define TRACE_EVENT(name, proto, args, struct, assign, print) \
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DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
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#endif
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#endif
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