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![Mathieu Desnoyers](/assets/img/avatar_default.png)
Impact: API *CHANGE*. Must update all tracepoint users. Add DEFINE_TRACE() to tracepoints to let them declare the tracepoint structure in a single spot for all the kernel. It helps reducing memory consumption, especially when declaring a lot of tracepoints, e.g. for kmalloc tracing. *API CHANGE WARNING*: now, DECLARE_TRACE() must be used in headers for tracepoint declarations rather than DEFINE_TRACE(). This is the sane way to do it. The name previously used was misleading. Updates scheduler instrumentation to follow this API change. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu>
156 lines
4.6 KiB
C
156 lines
4.6 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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#define TPPROTO(args...) args
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#define TPARGS(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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TPPROTO(proto), TPARGS(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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/*
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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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#endif
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