c1df1bd2c4
Impact: new API Add a new API trace_mark_tp(), which declares a marker within a tracepoint probe. When the marker is activated, the tracepoint is automatically enabled. No branch test is used at the marker site, because it would be a duplicate of the branch already present in the tracepoint. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu>
213 lines
6.8 KiB
C
213 lines
6.8 KiB
C
#ifndef _LINUX_MARKER_H
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#define _LINUX_MARKER_H
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/*
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* Code markup for dynamic and static tracing.
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*
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* See Documentation/marker.txt.
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*
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* (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
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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 <stdarg.h>
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#include <linux/types.h>
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struct module;
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struct marker;
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/**
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* marker_probe_func - Type of a marker probe function
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* @probe_private: probe private data
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* @call_private: call site private data
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* @fmt: format string
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* @args: variable argument list pointer. Use a pointer to overcome C's
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* inability to pass this around as a pointer in a portable manner in
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* the callee otherwise.
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*
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* Type of marker probe functions. They receive the mdata and need to parse the
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* format string to recover the variable argument list.
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*/
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typedef void marker_probe_func(void *probe_private, void *call_private,
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const char *fmt, va_list *args);
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struct marker_probe_closure {
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marker_probe_func *func; /* Callback */
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void *probe_private; /* Private probe data */
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};
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struct marker {
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const char *name; /* Marker name */
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const char *format; /* Marker format string, describing the
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* variable argument list.
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*/
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char state; /* Marker state. */
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char ptype; /* probe type : 0 : single, 1 : multi */
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/* Probe wrapper */
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void (*call)(const struct marker *mdata, void *call_private, ...);
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struct marker_probe_closure single;
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struct marker_probe_closure *multi;
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const char *tp_name; /* Optional tracepoint name */
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void *tp_cb; /* Optional tracepoint callback */
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} __attribute__((aligned(8)));
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#ifdef CONFIG_MARKERS
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/*
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* Note : the empty asm volatile with read constraint is used here instead of a
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* "used" attribute to fix a gcc 4.1.x bug.
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* Make sure the alignment of the structure in the __markers 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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* The "generic" argument controls which marker enabling mechanism must be used.
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* If generic is true, a variable read is used.
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* If generic is false, immediate values are used.
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*/
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#define __trace_mark(generic, name, call_private, format, args...) \
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do { \
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static const char __mstrtab_##name[] \
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__attribute__((section("__markers_strings"))) \
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= #name "\0" format; \
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static struct marker __mark_##name \
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__attribute__((section("__markers"), aligned(8))) = \
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{ __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \
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0, 0, marker_probe_cb, \
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{ __mark_empty_function, NULL}, NULL, NULL, NULL }; \
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__mark_check_format(format, ## args); \
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if (unlikely(__mark_##name.state)) { \
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(*__mark_##name.call) \
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(&__mark_##name, call_private, ## args);\
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} \
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} while (0)
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#define __trace_mark_tp(name, call_private, tp_name, tp_cb, format, args...) \
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do { \
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void __check_tp_type(void) \
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{ \
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register_trace_##tp_name(tp_cb); \
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} \
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static const char __mstrtab_##name[] \
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__attribute__((section("__markers_strings"))) \
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= #name "\0" format; \
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static struct marker __mark_##name \
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__attribute__((section("__markers"), aligned(8))) = \
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{ __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \
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0, 0, marker_probe_cb, \
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{ __mark_empty_function, NULL}, NULL, #tp_name, tp_cb };\
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__mark_check_format(format, ## args); \
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(*__mark_##name.call)(&__mark_##name, call_private, \
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## args); \
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} while (0)
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extern void marker_update_probe_range(struct marker *begin,
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struct marker *end);
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#else /* !CONFIG_MARKERS */
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#define __trace_mark(generic, name, call_private, format, args...) \
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__mark_check_format(format, ## args)
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#define __trace_mark_tp(name, call_private, tp_name, tp_cb, format, args...) \
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do { \
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void __check_tp_type(void) \
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{ \
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register_trace_##tp_name(tp_cb); \
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} \
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__mark_check_format(format, ## args); \
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} while (0)
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static inline void marker_update_probe_range(struct marker *begin,
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struct marker *end)
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{ }
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#endif /* CONFIG_MARKERS */
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/**
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* trace_mark - Marker using code patching
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* @name: marker name, not quoted.
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* @format: format string
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* @args...: variable argument list
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*
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* Places a marker using optimized code patching technique (imv_read())
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* to be enabled when immediate values are present.
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*/
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#define trace_mark(name, format, args...) \
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__trace_mark(0, name, NULL, format, ## args)
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/**
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* _trace_mark - Marker using variable read
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* @name: marker name, not quoted.
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* @format: format string
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* @args...: variable argument list
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*
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* Places a marker using a standard memory read (_imv_read()) to be
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* enabled. Should be used for markers in code paths where instruction
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* modification based enabling is not welcome. (__init and __exit functions,
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* lockdep, some traps, printk).
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*/
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#define _trace_mark(name, format, args...) \
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__trace_mark(1, name, NULL, format, ## args)
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/**
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* trace_mark_tp - Marker in a tracepoint callback
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* @name: marker name, not quoted.
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* @tp_name: tracepoint name, not quoted.
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* @tp_cb: tracepoint callback. Should have an associated global symbol so it
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* is not optimized away by the compiler (should not be static).
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* @format: format string
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* @args...: variable argument list
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*
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* Places a marker in a tracepoint callback.
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*/
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#define trace_mark_tp(name, tp_name, tp_cb, format, args...) \
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__trace_mark_tp(name, NULL, tp_name, tp_cb, format, ## args)
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/**
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* MARK_NOARGS - Format string for a marker with no argument.
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*/
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#define MARK_NOARGS " "
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/* To be used for string format validity checking with gcc */
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static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
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{
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}
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#define __mark_check_format(format, args...) \
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do { \
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if (0) \
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___mark_check_format(format, ## args); \
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} while (0)
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extern marker_probe_func __mark_empty_function;
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extern void marker_probe_cb(const struct marker *mdata,
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void *call_private, ...);
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/*
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* Connect a probe to a marker.
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* private data pointer must be a valid allocated memory address, or NULL.
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*/
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extern int marker_probe_register(const char *name, const char *format,
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marker_probe_func *probe, void *probe_private);
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/*
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* Returns the private data given to marker_probe_register.
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*/
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extern int marker_probe_unregister(const char *name,
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marker_probe_func *probe, void *probe_private);
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/*
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* Unregister a marker by providing the registered private data.
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*/
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extern int marker_probe_unregister_private_data(marker_probe_func *probe,
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void *probe_private);
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extern void *marker_get_private_data(const char *name, marker_probe_func *probe,
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int num);
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/*
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* marker_synchronize_unregister must be called between the last marker probe
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* unregistration and the end of module exit to make sure there is no caller
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* executing a probe when it is freed.
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*/
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#define marker_synchronize_unregister() synchronize_sched()
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#endif
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