1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */
29cfe06f8SSteven Rostedt /*
39cfe06f8SSteven Rostedt * If TRACE_SYSTEM is defined, that will be the directory created
44e20e3a6SSteven Rostedt (Red Hat) * in the ftrace directory under /sys/kernel/tracing/events/<system>
59cfe06f8SSteven Rostedt *
644ad18e0SSteven Rostedt * The define_trace.h below will also look for a file name of
79cfe06f8SSteven Rostedt * TRACE_SYSTEM.h where TRACE_SYSTEM is what is defined here.
867aedeb8SChunyan Zhang * In this case, it would look for sample-trace.h
99cfe06f8SSteven Rostedt *
1044ad18e0SSteven Rostedt * If the header name will be different than the system name
1144ad18e0SSteven Rostedt * (as in this case), then you can override the header name that
1244ad18e0SSteven Rostedt * define_trace.h will look up by defining TRACE_INCLUDE_FILE
139cfe06f8SSteven Rostedt *
1444ad18e0SSteven Rostedt * This file is called trace-events-sample.h but we want the system
1567aedeb8SChunyan Zhang * to be called "sample-trace". Therefore we must define the name of this
1644ad18e0SSteven Rostedt * file:
179cfe06f8SSteven Rostedt *
1844ad18e0SSteven Rostedt * #define TRACE_INCLUDE_FILE trace-events-sample
199cfe06f8SSteven Rostedt *
2044ad18e0SSteven Rostedt * As we do an the bottom of this file.
21d0b6e04aSLi Zefan *
22d0b6e04aSLi Zefan * Notice that TRACE_SYSTEM should be defined outside of #if
23d0b6e04aSLi Zefan * protection, just like TRACE_INCLUDE_FILE.
249cfe06f8SSteven Rostedt */
259cfe06f8SSteven Rostedt #undef TRACE_SYSTEM
2688920427SSteven Rostedt (Red Hat) #define TRACE_SYSTEM sample-trace
2788920427SSteven Rostedt (Red Hat)
2888920427SSteven Rostedt (Red Hat) /*
2988920427SSteven Rostedt (Red Hat) * TRACE_SYSTEM is expected to be a C valid variable (alpha-numeric
3088920427SSteven Rostedt (Red Hat) * and underscore), although it may start with numbers. If for some
3188920427SSteven Rostedt (Red Hat) * reason it is not, you need to add the following lines:
3288920427SSteven Rostedt (Red Hat) */
3388920427SSteven Rostedt (Red Hat) #undef TRACE_SYSTEM_VAR
3488920427SSteven Rostedt (Red Hat) #define TRACE_SYSTEM_VAR sample_trace
3588920427SSteven Rostedt (Red Hat) /*
3688920427SSteven Rostedt (Red Hat) * But the above is only needed if TRACE_SYSTEM is not alpha-numeric
3788920427SSteven Rostedt (Red Hat) * and underscored. By default, TRACE_SYSTEM_VAR will be equal to
3888920427SSteven Rostedt (Red Hat) * TRACE_SYSTEM. As TRACE_SYSTEM_VAR must be alpha-numeric, if
3988920427SSteven Rostedt (Red Hat) * TRACE_SYSTEM is not, then TRACE_SYSTEM_VAR must be defined with
4088920427SSteven Rostedt (Red Hat) * only alpha-numeric and underscores.
4188920427SSteven Rostedt (Red Hat) *
4288920427SSteven Rostedt (Red Hat) * The TRACE_SYSTEM_VAR is only used internally and not visible to
4388920427SSteven Rostedt (Red Hat) * user space.
4488920427SSteven Rostedt (Red Hat) */
459cfe06f8SSteven Rostedt
469cfe06f8SSteven Rostedt /*
47d0b6e04aSLi Zefan * Notice that this file is not protected like a normal header.
48d0b6e04aSLi Zefan * We also must allow for rereading of this file. The
49d0b6e04aSLi Zefan *
50d0b6e04aSLi Zefan * || defined(TRACE_HEADER_MULTI_READ)
51d0b6e04aSLi Zefan *
52d0b6e04aSLi Zefan * serves this purpose.
53d0b6e04aSLi Zefan */
54d0b6e04aSLi Zefan #if !defined(_TRACE_EVENT_SAMPLE_H) || defined(TRACE_HEADER_MULTI_READ)
55d0b6e04aSLi Zefan #define _TRACE_EVENT_SAMPLE_H
56d0b6e04aSLi Zefan
57d0b6e04aSLi Zefan /*
58d0b6e04aSLi Zefan * All trace headers should include tracepoint.h, until we finally
59d0b6e04aSLi Zefan * make it into a standard header.
60d0b6e04aSLi Zefan */
61d0b6e04aSLi Zefan #include <linux/tracepoint.h>
62d0b6e04aSLi Zefan
63d0b6e04aSLi Zefan /*
649cfe06f8SSteven Rostedt * The TRACE_EVENT macro is broken up into 5 parts.
659cfe06f8SSteven Rostedt *
669cfe06f8SSteven Rostedt * name: name of the trace point. This is also how to enable the tracepoint.
679cfe06f8SSteven Rostedt * A function called trace_foo_bar() will be created.
689cfe06f8SSteven Rostedt *
699cfe06f8SSteven Rostedt * proto: the prototype of the function trace_foo_bar()
709cfe06f8SSteven Rostedt * Here it is trace_foo_bar(char *foo, int bar).
719cfe06f8SSteven Rostedt *
729cfe06f8SSteven Rostedt * args: must match the arguments in the prototype.
739cfe06f8SSteven Rostedt * Here it is simply "foo, bar".
749cfe06f8SSteven Rostedt *
759cfe06f8SSteven Rostedt * struct: This defines the way the data will be stored in the ring buffer.
764e20e3a6SSteven Rostedt (Red Hat) * The items declared here become part of a special structure
774e20e3a6SSteven Rostedt (Red Hat) * called "__entry", which can be used in the fast_assign part of the
784e20e3a6SSteven Rostedt (Red Hat) * TRACE_EVENT macro.
799cfe06f8SSteven Rostedt *
804e20e3a6SSteven Rostedt (Red Hat) * Here are the currently defined types you can use:
814e20e3a6SSteven Rostedt (Red Hat) *
824e20e3a6SSteven Rostedt (Red Hat) * __field : Is broken up into type and name. Where type can be any
834e20e3a6SSteven Rostedt (Red Hat) * primitive type (integer, long or pointer).
844e20e3a6SSteven Rostedt (Red Hat) *
854e20e3a6SSteven Rostedt (Red Hat) * __field(int, foo)
864e20e3a6SSteven Rostedt (Red Hat) *
874e20e3a6SSteven Rostedt (Red Hat) * __entry->foo = 5;
884e20e3a6SSteven Rostedt (Red Hat) *
894e20e3a6SSteven Rostedt (Red Hat) * __field_struct : This can be any static complex data type (struct, union
904e20e3a6SSteven Rostedt (Red Hat) * but not an array). Be careful using complex types, as each
914e20e3a6SSteven Rostedt (Red Hat) * event is limited in size, and copying large amounts of data
924e20e3a6SSteven Rostedt (Red Hat) * into the ring buffer can slow things down.
934e20e3a6SSteven Rostedt (Red Hat) *
944e20e3a6SSteven Rostedt (Red Hat) * __field_struct(struct bar, foo)
954e20e3a6SSteven Rostedt (Red Hat) *
964e20e3a6SSteven Rostedt (Red Hat) * __entry->bar.x = y;
974e20e3a6SSteven Rostedt (Red Hat)
984e20e3a6SSteven Rostedt (Red Hat) * __array: There are three fields (type, name, size). The type is the
9927019975SJeremy Linton * type of elements in the array, the name is the name of the array.
1004e20e3a6SSteven Rostedt (Red Hat) * size is the number of items in the array (not the total size).
1014e20e3a6SSteven Rostedt (Red Hat) *
1024e20e3a6SSteven Rostedt (Red Hat) * __array( char, foo, 10) is the same as saying: char foo[10];
1034e20e3a6SSteven Rostedt (Red Hat) *
1044e20e3a6SSteven Rostedt (Red Hat) * Assigning arrays can be done like any array:
1054e20e3a6SSteven Rostedt (Red Hat) *
1064e20e3a6SSteven Rostedt (Red Hat) * __entry->foo[0] = 'a';
1074e20e3a6SSteven Rostedt (Red Hat) *
1084e20e3a6SSteven Rostedt (Red Hat) * memcpy(__entry->foo, bar, 10);
1094e20e3a6SSteven Rostedt (Red Hat) *
11067aedeb8SChunyan Zhang * __dynamic_array: This is similar to array, but can vary its size from
1114e20e3a6SSteven Rostedt (Red Hat) * instance to instance of the tracepoint being called.
1124e20e3a6SSteven Rostedt (Red Hat) * Like __array, this too has three elements (type, name, size);
1134e20e3a6SSteven Rostedt (Red Hat) * type is the type of the element, name is the name of the array.
1144e20e3a6SSteven Rostedt (Red Hat) * The size is different than __array. It is not a static number,
1154e20e3a6SSteven Rostedt (Red Hat) * but the algorithm to figure out the length of the array for the
11627019975SJeremy Linton * specific instance of tracepoint. Again, size is the number of
1174e20e3a6SSteven Rostedt (Red Hat) * items in the array, not the total length in bytes.
1184e20e3a6SSteven Rostedt (Red Hat) *
1194e20e3a6SSteven Rostedt (Red Hat) * __dynamic_array( int, foo, bar) is similar to: int foo[bar];
1204e20e3a6SSteven Rostedt (Red Hat) *
1214e20e3a6SSteven Rostedt (Red Hat) * Note, unlike arrays, you must use the __get_dynamic_array() macro
1224e20e3a6SSteven Rostedt (Red Hat) * to access the array.
1234e20e3a6SSteven Rostedt (Red Hat) *
1244e20e3a6SSteven Rostedt (Red Hat) * memcpy(__get_dynamic_array(foo), bar, 10);
1254e20e3a6SSteven Rostedt (Red Hat) *
1264e20e3a6SSteven Rostedt (Red Hat) * Notice, that "__entry" is not needed here.
1274e20e3a6SSteven Rostedt (Red Hat) *
1284e20e3a6SSteven Rostedt (Red Hat) * __string: This is a special kind of __dynamic_array. It expects to
12927019975SJeremy Linton * have a null terminated character array passed to it (it allows
1304e20e3a6SSteven Rostedt (Red Hat) * for NULL too, which would be converted into "(null)"). __string
13127019975SJeremy Linton * takes two parameter (name, src), where name is the name of
1324e20e3a6SSteven Rostedt (Red Hat) * the string saved, and src is the string to copy into the
1334e20e3a6SSteven Rostedt (Red Hat) * ring buffer.
1344e20e3a6SSteven Rostedt (Red Hat) *
1354e20e3a6SSteven Rostedt (Red Hat) * __string(foo, bar) is similar to: strcpy(foo, bar)
1364e20e3a6SSteven Rostedt (Red Hat) *
1374e20e3a6SSteven Rostedt (Red Hat) * To assign a string, use the helper macro __assign_str().
1384e20e3a6SSteven Rostedt (Red Hat) *
1394e20e3a6SSteven Rostedt (Red Hat) * __assign_str(foo, bar);
1404e20e3a6SSteven Rostedt (Red Hat) *
1414e20e3a6SSteven Rostedt (Red Hat) * In most cases, the __assign_str() macro will take the same
1424e20e3a6SSteven Rostedt (Red Hat) * parameters as the __string() macro had to declare the string.
1434e20e3a6SSteven Rostedt (Red Hat) *
144fea6ac55SSteven Rostedt (Google) * __vstring: This is similar to __string() but instead of taking a
145fea6ac55SSteven Rostedt (Google) * dynamic length, it takes a variable list va_list 'va' variable.
146fea6ac55SSteven Rostedt (Google) * Some event callers already have a message from parameters saved
147fea6ac55SSteven Rostedt (Google) * in a va_list. Passing in the format and the va_list variable
148fea6ac55SSteven Rostedt (Google) * will save just enough on the ring buffer for that string.
149fea6ac55SSteven Rostedt (Google) * Note, the va variable used is a pointer to a va_list, not
150fea6ac55SSteven Rostedt (Google) * to the va_list directly.
151fea6ac55SSteven Rostedt (Google) *
152fea6ac55SSteven Rostedt (Google) * (va_list *va)
153fea6ac55SSteven Rostedt (Google) *
154fea6ac55SSteven Rostedt (Google) * __vstring(foo, fmt, va) is similar to: vsnprintf(foo, fmt, va)
155fea6ac55SSteven Rostedt (Google) *
156fea6ac55SSteven Rostedt (Google) * To assign the string, use the helper macro __assign_vstr().
157fea6ac55SSteven Rostedt (Google) *
158fea6ac55SSteven Rostedt (Google) * __assign_vstr(foo, fmt, va);
159fea6ac55SSteven Rostedt (Google) *
160fea6ac55SSteven Rostedt (Google) * In most cases, the __assign_vstr() macro will take the same
161fea6ac55SSteven Rostedt (Google) * parameters as the __vstring() macro had to declare the string.
162fea6ac55SSteven Rostedt (Google) * Use __get_str() to retrieve the __vstring() just like it would for
163fea6ac55SSteven Rostedt (Google) * __string().
164fea6ac55SSteven Rostedt (Google) *
165883b4aeeSSteven Rostedt (VMware) * __string_len: This is a helper to a __dynamic_array, but it understands
166883b4aeeSSteven Rostedt (VMware) * that the array has characters in it, and with the combined
167883b4aeeSSteven Rostedt (VMware) * use of __assign_str_len(), it will allocate 'len' + 1 bytes
168883b4aeeSSteven Rostedt (VMware) * in the ring buffer and add a '\0' to the string. This is
169883b4aeeSSteven Rostedt (VMware) * useful if the string being saved has no terminating '\0' byte.
170883b4aeeSSteven Rostedt (VMware) * It requires that the length of the string is known as it acts
171883b4aeeSSteven Rostedt (VMware) * like a memcpy().
172883b4aeeSSteven Rostedt (VMware) *
173883b4aeeSSteven Rostedt (VMware) * Declared with:
174883b4aeeSSteven Rostedt (VMware) *
175883b4aeeSSteven Rostedt (VMware) * __string_len(foo, bar, len)
176883b4aeeSSteven Rostedt (VMware) *
177883b4aeeSSteven Rostedt (VMware) * To assign this string, use the helper macro __assign_str_len().
178883b4aeeSSteven Rostedt (VMware) *
179ecbe794eSGeliang Tang * __assign_str_len(foo, bar, len);
180883b4aeeSSteven Rostedt (VMware) *
181883b4aeeSSteven Rostedt (VMware) * Then len + 1 is allocated to the ring buffer, and a nul terminating
182883b4aeeSSteven Rostedt (VMware) * byte is added. This is similar to:
183883b4aeeSSteven Rostedt (VMware) *
184883b4aeeSSteven Rostedt (VMware) * memcpy(__get_str(foo), bar, len);
185883b4aeeSSteven Rostedt (VMware) * __get_str(foo)[len] = 0;
186883b4aeeSSteven Rostedt (VMware) *
187883b4aeeSSteven Rostedt (VMware) * The advantage of using this over __dynamic_array, is that it
188883b4aeeSSteven Rostedt (VMware) * takes care of allocating the extra byte on the ring buffer
189883b4aeeSSteven Rostedt (VMware) * for the '\0' terminating byte, and __get_str(foo) can be used
190883b4aeeSSteven Rostedt (VMware) * in the TP_printk().
191883b4aeeSSteven Rostedt (VMware) *
1924e20e3a6SSteven Rostedt (Red Hat) * __bitmask: This is another kind of __dynamic_array, but it expects
1934e20e3a6SSteven Rostedt (Red Hat) * an array of longs, and the number of bits to parse. It takes
1944e20e3a6SSteven Rostedt (Red Hat) * two parameters (name, nr_bits), where name is the name of the
1954e20e3a6SSteven Rostedt (Red Hat) * bitmask to save, and the nr_bits is the number of bits to record.
1964e20e3a6SSteven Rostedt (Red Hat) *
1974e20e3a6SSteven Rostedt (Red Hat) * __bitmask(target_cpu, nr_cpumask_bits)
1984e20e3a6SSteven Rostedt (Red Hat) *
1994e20e3a6SSteven Rostedt (Red Hat) * To assign a bitmask, use the __assign_bitmask() helper macro.
2004e20e3a6SSteven Rostedt (Red Hat) *
2014e20e3a6SSteven Rostedt (Red Hat) * __assign_bitmask(target_cpus, cpumask_bits(bar), nr_cpumask_bits);
2024e20e3a6SSteven Rostedt (Red Hat) *
2038230f27bSSteven Rostedt (Google) * __cpumask: This is pretty much the same as __bitmask but is specific for
2048230f27bSSteven Rostedt (Google) * CPU masks. The type displayed to the user via the format files will
2058230f27bSSteven Rostedt (Google) * be "cpumaks_t" such that user space may deal with them differently
2068230f27bSSteven Rostedt (Google) * if they choose to do so, and the bits is always set to nr_cpumask_bits.
2078230f27bSSteven Rostedt (Google) *
2088230f27bSSteven Rostedt (Google) * __cpumask(target_cpu)
2098230f27bSSteven Rostedt (Google) *
2108230f27bSSteven Rostedt (Google) * To assign a cpumask, use the __assign_cpumask() helper macro.
2118230f27bSSteven Rostedt (Google) *
2128230f27bSSteven Rostedt (Google) * __assign_cpumask(target_cpus, cpumask_bits(bar));
2139cfe06f8SSteven Rostedt *
2149cfe06f8SSteven Rostedt * fast_assign: This is a C like function that is used to store the items
2154e20e3a6SSteven Rostedt (Red Hat) * into the ring buffer. A special variable called "__entry" will be the
2164e20e3a6SSteven Rostedt (Red Hat) * structure that points into the ring buffer and has the same fields as
2174e20e3a6SSteven Rostedt (Red Hat) * described by the struct part of TRACE_EVENT above.
2189cfe06f8SSteven Rostedt *
2199cfe06f8SSteven Rostedt * printk: This is a way to print out the data in pretty print. This is
2209cfe06f8SSteven Rostedt * useful if the system crashes and you are logging via a serial line,
2219cfe06f8SSteven Rostedt * the data can be printed to the console using this "printk" method.
2224e20e3a6SSteven Rostedt (Red Hat) * This is also used to print out the data from the trace files.
2234e20e3a6SSteven Rostedt (Red Hat) * Again, the __entry macro is used to access the data from the ring buffer.
2244e20e3a6SSteven Rostedt (Red Hat) *
2258230f27bSSteven Rostedt (Google) * Note, __dynamic_array, __string, __bitmask and __cpumask require special
2268230f27bSSteven Rostedt (Google) * helpers to access the data.
2274e20e3a6SSteven Rostedt (Red Hat) *
2284e20e3a6SSteven Rostedt (Red Hat) * For __dynamic_array(int, foo, bar) use __get_dynamic_array(foo)
2294e20e3a6SSteven Rostedt (Red Hat) * Use __get_dynamic_array_len(foo) to get the length of the array
230d6726c81SSteven Rostedt (Red Hat) * saved. Note, __get_dynamic_array_len() returns the total allocated
231d6726c81SSteven Rostedt (Red Hat) * length of the dynamic array; __print_array() expects the second
232d6726c81SSteven Rostedt (Red Hat) * parameter to be the number of elements. To get that, the array length
233d6726c81SSteven Rostedt (Red Hat) * needs to be divided by the element size.
2344e20e3a6SSteven Rostedt (Red Hat) *
2354e20e3a6SSteven Rostedt (Red Hat) * For __string(foo, bar) use __get_str(foo)
2364e20e3a6SSteven Rostedt (Red Hat) *
2374e20e3a6SSteven Rostedt (Red Hat) * For __bitmask(target_cpus, nr_cpumask_bits) use __get_bitmask(target_cpus)
2384e20e3a6SSteven Rostedt (Red Hat) *
2398230f27bSSteven Rostedt (Google) * For __cpumask(target_cpus) use __get_cpumask(target_cpus)
2408230f27bSSteven Rostedt (Google) *
2419cfe06f8SSteven Rostedt *
2429cfe06f8SSteven Rostedt * Note, that for both the assign and the printk, __entry is the handler
2439cfe06f8SSteven Rostedt * to the data structure in the ring buffer, and is defined by the
2449cfe06f8SSteven Rostedt * TP_STRUCT__entry.
2459cfe06f8SSteven Rostedt */
2464e20e3a6SSteven Rostedt (Red Hat)
2474e20e3a6SSteven Rostedt (Red Hat) /*
2484e20e3a6SSteven Rostedt (Red Hat) * It is OK to have helper functions in the file, but they need to be protected
2494e20e3a6SSteven Rostedt (Red Hat) * from being defined more than once. Remember, this file gets included more
2504e20e3a6SSteven Rostedt (Red Hat) * than once.
2514e20e3a6SSteven Rostedt (Red Hat) */
2524e20e3a6SSteven Rostedt (Red Hat) #ifndef __TRACE_EVENT_SAMPLE_HELPER_FUNCTIONS
2534e20e3a6SSteven Rostedt (Red Hat) #define __TRACE_EVENT_SAMPLE_HELPER_FUNCTIONS
__length_of(const int * list)2544e20e3a6SSteven Rostedt (Red Hat) static inline int __length_of(const int *list)
2554e20e3a6SSteven Rostedt (Red Hat) {
2564e20e3a6SSteven Rostedt (Red Hat) int i;
2574e20e3a6SSteven Rostedt (Red Hat)
2584e20e3a6SSteven Rostedt (Red Hat) if (!list)
2594e20e3a6SSteven Rostedt (Red Hat) return 0;
2604e20e3a6SSteven Rostedt (Red Hat)
2614e20e3a6SSteven Rostedt (Red Hat) for (i = 0; list[i]; i++)
2624e20e3a6SSteven Rostedt (Red Hat) ;
2634e20e3a6SSteven Rostedt (Red Hat) return i;
2644e20e3a6SSteven Rostedt (Red Hat) }
26532eb3d0dSSteven Rostedt (Red Hat)
26632eb3d0dSSteven Rostedt (Red Hat) enum {
26732eb3d0dSSteven Rostedt (Red Hat) TRACE_SAMPLE_FOO = 2,
26832eb3d0dSSteven Rostedt (Red Hat) TRACE_SAMPLE_BAR = 4,
26932eb3d0dSSteven Rostedt (Red Hat) TRACE_SAMPLE_ZOO = 8,
27032eb3d0dSSteven Rostedt (Red Hat) };
2714e20e3a6SSteven Rostedt (Red Hat) #endif
2724e20e3a6SSteven Rostedt (Red Hat)
27332eb3d0dSSteven Rostedt (Red Hat) /*
27432eb3d0dSSteven Rostedt (Red Hat) * If enums are used in the TP_printk(), their names will be shown in
27532eb3d0dSSteven Rostedt (Red Hat) * format files and not their values. This can cause problems with user
27632eb3d0dSSteven Rostedt (Red Hat) * space programs that parse the format files to know how to translate
27732eb3d0dSSteven Rostedt (Red Hat) * the raw binary trace output into human readable text.
27832eb3d0dSSteven Rostedt (Red Hat) *
27932eb3d0dSSteven Rostedt (Red Hat) * To help out user space programs, any enum that is used in the TP_printk()
28032eb3d0dSSteven Rostedt (Red Hat) * should be defined by TRACE_DEFINE_ENUM() macro. All that is needed to
28132eb3d0dSSteven Rostedt (Red Hat) * be done is to add this macro with the enum within it in the trace
28232eb3d0dSSteven Rostedt (Red Hat) * header file, and it will be converted in the output.
28332eb3d0dSSteven Rostedt (Red Hat) */
28432eb3d0dSSteven Rostedt (Red Hat)
28532eb3d0dSSteven Rostedt (Red Hat) TRACE_DEFINE_ENUM(TRACE_SAMPLE_FOO);
28632eb3d0dSSteven Rostedt (Red Hat) TRACE_DEFINE_ENUM(TRACE_SAMPLE_BAR);
28732eb3d0dSSteven Rostedt (Red Hat) TRACE_DEFINE_ENUM(TRACE_SAMPLE_ZOO);
28832eb3d0dSSteven Rostedt (Red Hat)
2899cfe06f8SSteven Rostedt TRACE_EVENT(foo_bar,
2909cfe06f8SSteven Rostedt
2914e20e3a6SSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar, const int *lst,
292fea6ac55SSteven Rostedt (Google) const char *string, const struct cpumask *mask,
293fea6ac55SSteven Rostedt (Google) const char *fmt, va_list *va),
2949cfe06f8SSteven Rostedt
295fea6ac55SSteven Rostedt (Google) TP_ARGS(foo, bar, lst, string, mask, fmt, va),
2969cfe06f8SSteven Rostedt
2979cfe06f8SSteven Rostedt TP_STRUCT__entry(
2989cfe06f8SSteven Rostedt __array( char, foo, 10 )
2999cfe06f8SSteven Rostedt __field( int, bar )
3004e20e3a6SSteven Rostedt (Red Hat) __dynamic_array(int, list, __length_of(lst))
3014e20e3a6SSteven Rostedt (Red Hat) __string( str, string )
3024e20e3a6SSteven Rostedt (Red Hat) __bitmask( cpus, num_possible_cpus() )
3038230f27bSSteven Rostedt (Google) __cpumask( cpum )
304fea6ac55SSteven Rostedt (Google) __vstring( vstr, fmt, va )
3059cfe06f8SSteven Rostedt ),
3069cfe06f8SSteven Rostedt
3079cfe06f8SSteven Rostedt TP_fast_assign(
308d8fae2f6SZhao Hongjiang strlcpy(__entry->foo, foo, 10);
3099cfe06f8SSteven Rostedt __entry->bar = bar;
3104e20e3a6SSteven Rostedt (Red Hat) memcpy(__get_dynamic_array(list), lst,
3114e20e3a6SSteven Rostedt (Red Hat) __length_of(lst) * sizeof(int));
3124e20e3a6SSteven Rostedt (Red Hat) __assign_str(str, string);
313fea6ac55SSteven Rostedt (Google) __assign_vstr(vstr, fmt, va);
3144e20e3a6SSteven Rostedt (Red Hat) __assign_bitmask(cpus, cpumask_bits(mask), num_possible_cpus());
3158230f27bSSteven Rostedt (Google) __assign_cpumask(cpum, cpumask_bits(mask));
3169cfe06f8SSteven Rostedt ),
3179cfe06f8SSteven Rostedt
3188230f27bSSteven Rostedt (Google) TP_printk("foo %s %d %s %s %s %s (%s) (%s) %s", __entry->foo, __entry->bar,
31932eb3d0dSSteven Rostedt (Red Hat)
32032eb3d0dSSteven Rostedt (Red Hat) /*
32132eb3d0dSSteven Rostedt (Red Hat) * Notice here the use of some helper functions. This includes:
32232eb3d0dSSteven Rostedt (Red Hat) *
32332eb3d0dSSteven Rostedt (Red Hat) * __print_symbolic( variable, { value, "string" }, ... ),
32432eb3d0dSSteven Rostedt (Red Hat) *
32532eb3d0dSSteven Rostedt (Red Hat) * The variable is tested against each value of the { } pair. If
32632eb3d0dSSteven Rostedt (Red Hat) * the variable matches one of the values, then it will print the
32732eb3d0dSSteven Rostedt (Red Hat) * string in that pair. If non are matched, it returns a string
32832eb3d0dSSteven Rostedt (Red Hat) * version of the number (if __entry->bar == 7 then "7" is returned).
32932eb3d0dSSteven Rostedt (Red Hat) */
33032eb3d0dSSteven Rostedt (Red Hat) __print_symbolic(__entry->bar,
33132eb3d0dSSteven Rostedt (Red Hat) { 0, "zero" },
33232eb3d0dSSteven Rostedt (Red Hat) { TRACE_SAMPLE_FOO, "TWO" },
33332eb3d0dSSteven Rostedt (Red Hat) { TRACE_SAMPLE_BAR, "FOUR" },
33432eb3d0dSSteven Rostedt (Red Hat) { TRACE_SAMPLE_ZOO, "EIGHT" },
33532eb3d0dSSteven Rostedt (Red Hat) { 10, "TEN" }
33632eb3d0dSSteven Rostedt (Red Hat) ),
33732eb3d0dSSteven Rostedt (Red Hat)
33832eb3d0dSSteven Rostedt (Red Hat) /*
33932eb3d0dSSteven Rostedt (Red Hat) * __print_flags( variable, "delim", { value, "flag" }, ... ),
34032eb3d0dSSteven Rostedt (Red Hat) *
34132eb3d0dSSteven Rostedt (Red Hat) * This is similar to __print_symbolic, except that it tests the bits
34232eb3d0dSSteven Rostedt (Red Hat) * of the value. If ((FLAG & variable) == FLAG) then the string is
34332eb3d0dSSteven Rostedt (Red Hat) * printed. If more than one flag matches, then each one that does is
34432eb3d0dSSteven Rostedt (Red Hat) * also printed with delim in between them.
34532eb3d0dSSteven Rostedt (Red Hat) * If not all bits are accounted for, then the not found bits will be
34632eb3d0dSSteven Rostedt (Red Hat) * added in hex format: 0x506 will show BIT2|BIT4|0x500
34732eb3d0dSSteven Rostedt (Red Hat) */
34832eb3d0dSSteven Rostedt (Red Hat) __print_flags(__entry->bar, "|",
34932eb3d0dSSteven Rostedt (Red Hat) { 1, "BIT1" },
35032eb3d0dSSteven Rostedt (Red Hat) { 2, "BIT2" },
35132eb3d0dSSteven Rostedt (Red Hat) { 4, "BIT3" },
35232eb3d0dSSteven Rostedt (Red Hat) { 8, "BIT4" }
35332eb3d0dSSteven Rostedt (Red Hat) ),
35432eb3d0dSSteven Rostedt (Red Hat) /*
35532eb3d0dSSteven Rostedt (Red Hat) * __print_array( array, len, element_size )
35632eb3d0dSSteven Rostedt (Red Hat) *
35732eb3d0dSSteven Rostedt (Red Hat) * This prints out the array that is defined by __array in a nice format.
35832eb3d0dSSteven Rostedt (Red Hat) */
3594e20e3a6SSteven Rostedt (Red Hat) __print_array(__get_dynamic_array(list),
360d6726c81SSteven Rostedt (Red Hat) __get_dynamic_array_len(list) / sizeof(int),
3614e20e3a6SSteven Rostedt (Red Hat) sizeof(int)),
362*eb9d5894SSteven Rostedt (Google) __get_str(str), __get_bitmask(cpus), __get_cpumask(cpum),
3638230f27bSSteven Rostedt (Google) __get_str(vstr))
3649cfe06f8SSteven Rostedt );
365c4c7eb29SSteven Rostedt (Red Hat)
366c4c7eb29SSteven Rostedt (Red Hat) /*
367c4c7eb29SSteven Rostedt (Red Hat) * There may be a case where a tracepoint should only be called if
368c4c7eb29SSteven Rostedt (Red Hat) * some condition is set. Otherwise the tracepoint should not be called.
369c4c7eb29SSteven Rostedt (Red Hat) * But to do something like:
370c4c7eb29SSteven Rostedt (Red Hat) *
371c4c7eb29SSteven Rostedt (Red Hat) * if (cond)
372c4c7eb29SSteven Rostedt (Red Hat) * trace_foo();
373c4c7eb29SSteven Rostedt (Red Hat) *
374c4c7eb29SSteven Rostedt (Red Hat) * Would cause a little overhead when tracing is not enabled, and that
375c4c7eb29SSteven Rostedt (Red Hat) * overhead, even if small, is not something we want. As tracepoints
376c4c7eb29SSteven Rostedt (Red Hat) * use static branch (aka jump_labels), where no branch is taken to
377c4c7eb29SSteven Rostedt (Red Hat) * skip the tracepoint when not enabled, and a jmp is placed to jump
378c4c7eb29SSteven Rostedt (Red Hat) * to the tracepoint code when it is enabled, having a if statement
379c4c7eb29SSteven Rostedt (Red Hat) * nullifies that optimization. It would be nice to place that
380c4c7eb29SSteven Rostedt (Red Hat) * condition within the static branch. This is where TRACE_EVENT_CONDITION
381c4c7eb29SSteven Rostedt (Red Hat) * comes in.
382c4c7eb29SSteven Rostedt (Red Hat) *
383c4c7eb29SSteven Rostedt (Red Hat) * TRACE_EVENT_CONDITION() is just like TRACE_EVENT, except it adds another
384c4c7eb29SSteven Rostedt (Red Hat) * parameter just after args. Where TRACE_EVENT has:
385c4c7eb29SSteven Rostedt (Red Hat) *
386c4c7eb29SSteven Rostedt (Red Hat) * TRACE_EVENT(name, proto, args, struct, assign, printk)
387c4c7eb29SSteven Rostedt (Red Hat) *
388c4c7eb29SSteven Rostedt (Red Hat) * the CONDITION version has:
389c4c7eb29SSteven Rostedt (Red Hat) *
390c4c7eb29SSteven Rostedt (Red Hat) * TRACE_EVENT_CONDITION(name, proto, args, cond, struct, assign, printk)
391c4c7eb29SSteven Rostedt (Red Hat) *
392c4c7eb29SSteven Rostedt (Red Hat) * Everything is the same as TRACE_EVENT except for the new cond. Think
393c4c7eb29SSteven Rostedt (Red Hat) * of the cond variable as:
394c4c7eb29SSteven Rostedt (Red Hat) *
395c4c7eb29SSteven Rostedt (Red Hat) * if (cond)
396c4c7eb29SSteven Rostedt (Red Hat) * trace_foo_bar_with_cond();
397c4c7eb29SSteven Rostedt (Red Hat) *
398c4c7eb29SSteven Rostedt (Red Hat) * Except that the logic for the if branch is placed after the static branch.
399c4c7eb29SSteven Rostedt (Red Hat) * That is, the if statement that processes the condition will not be
400c4c7eb29SSteven Rostedt (Red Hat) * executed unless that traecpoint is enabled. Otherwise it still remains
401c4c7eb29SSteven Rostedt (Red Hat) * a nop.
402c4c7eb29SSteven Rostedt (Red Hat) */
403c4c7eb29SSteven Rostedt (Red Hat) TRACE_EVENT_CONDITION(foo_bar_with_cond,
404c4c7eb29SSteven Rostedt (Red Hat)
405c4c7eb29SSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar),
406c4c7eb29SSteven Rostedt (Red Hat)
407c4c7eb29SSteven Rostedt (Red Hat) TP_ARGS(foo, bar),
408c4c7eb29SSteven Rostedt (Red Hat)
409c4c7eb29SSteven Rostedt (Red Hat) TP_CONDITION(!(bar % 10)),
410c4c7eb29SSteven Rostedt (Red Hat)
411c4c7eb29SSteven Rostedt (Red Hat) TP_STRUCT__entry(
412c4c7eb29SSteven Rostedt (Red Hat) __string( foo, foo )
413c4c7eb29SSteven Rostedt (Red Hat) __field( int, bar )
414c4c7eb29SSteven Rostedt (Red Hat) ),
415c4c7eb29SSteven Rostedt (Red Hat)
416c4c7eb29SSteven Rostedt (Red Hat) TP_fast_assign(
417c4c7eb29SSteven Rostedt (Red Hat) __assign_str(foo, foo);
418c4c7eb29SSteven Rostedt (Red Hat) __entry->bar = bar;
419c4c7eb29SSteven Rostedt (Red Hat) ),
420c4c7eb29SSteven Rostedt (Red Hat)
421c4c7eb29SSteven Rostedt (Red Hat) TP_printk("foo %s %d", __get_str(foo), __entry->bar)
422c4c7eb29SSteven Rostedt (Red Hat) );
4236adc13f8SSteven Rostedt (Red Hat)
4248cf868afSSteven Rostedt (Red Hat) int foo_bar_reg(void);
4256adc13f8SSteven Rostedt (Red Hat) void foo_bar_unreg(void);
4266adc13f8SSteven Rostedt (Red Hat)
4276adc13f8SSteven Rostedt (Red Hat) /*
4286adc13f8SSteven Rostedt (Red Hat) * Now in the case that some function needs to be called when the
4296adc13f8SSteven Rostedt (Red Hat) * tracepoint is enabled and/or when it is disabled, the
4306adc13f8SSteven Rostedt (Red Hat) * TRACE_EVENT_FN() serves this purpose. This is just like TRACE_EVENT()
4316adc13f8SSteven Rostedt (Red Hat) * but adds two more parameters at the end:
4326adc13f8SSteven Rostedt (Red Hat) *
4336adc13f8SSteven Rostedt (Red Hat) * TRACE_EVENT_FN( name, proto, args, struct, assign, printk, reg, unreg)
4346adc13f8SSteven Rostedt (Red Hat) *
4356adc13f8SSteven Rostedt (Red Hat) * reg and unreg are functions with the prototype of:
4366adc13f8SSteven Rostedt (Red Hat) *
4376adc13f8SSteven Rostedt (Red Hat) * void reg(void)
4386adc13f8SSteven Rostedt (Red Hat) *
4396adc13f8SSteven Rostedt (Red Hat) * The reg function gets called before the tracepoint is enabled, and
4406adc13f8SSteven Rostedt (Red Hat) * the unreg function gets called after the tracepoint is disabled.
4416adc13f8SSteven Rostedt (Red Hat) *
4426adc13f8SSteven Rostedt (Red Hat) * Note, reg and unreg are allowed to be NULL. If you only need to
4436adc13f8SSteven Rostedt (Red Hat) * call a function before enabling, or after disabling, just set one
4446adc13f8SSteven Rostedt (Red Hat) * function and pass in NULL for the other parameter.
4456adc13f8SSteven Rostedt (Red Hat) */
4466adc13f8SSteven Rostedt (Red Hat) TRACE_EVENT_FN(foo_bar_with_fn,
4476adc13f8SSteven Rostedt (Red Hat)
4486adc13f8SSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar),
4496adc13f8SSteven Rostedt (Red Hat)
4506adc13f8SSteven Rostedt (Red Hat) TP_ARGS(foo, bar),
4516adc13f8SSteven Rostedt (Red Hat)
4526adc13f8SSteven Rostedt (Red Hat) TP_STRUCT__entry(
4536adc13f8SSteven Rostedt (Red Hat) __string( foo, foo )
4546adc13f8SSteven Rostedt (Red Hat) __field( int, bar )
4556adc13f8SSteven Rostedt (Red Hat) ),
4566adc13f8SSteven Rostedt (Red Hat)
4576adc13f8SSteven Rostedt (Red Hat) TP_fast_assign(
4586adc13f8SSteven Rostedt (Red Hat) __assign_str(foo, foo);
4596adc13f8SSteven Rostedt (Red Hat) __entry->bar = bar;
4606adc13f8SSteven Rostedt (Red Hat) ),
4616adc13f8SSteven Rostedt (Red Hat)
4626adc13f8SSteven Rostedt (Red Hat) TP_printk("foo %s %d", __get_str(foo), __entry->bar),
4636adc13f8SSteven Rostedt (Red Hat)
4646adc13f8SSteven Rostedt (Red Hat) foo_bar_reg, foo_bar_unreg
4656adc13f8SSteven Rostedt (Red Hat) );
4666adc13f8SSteven Rostedt (Red Hat)
4677496946aSSteven Rostedt (Red Hat) /*
4687496946aSSteven Rostedt (Red Hat) * Each TRACE_EVENT macro creates several helper functions to produce
4697496946aSSteven Rostedt (Red Hat) * the code to add the tracepoint, create the files in the trace
4707496946aSSteven Rostedt (Red Hat) * directory, hook it to perf, assign the values and to print out
4717496946aSSteven Rostedt (Red Hat) * the raw data from the ring buffer. To prevent too much bloat,
4727496946aSSteven Rostedt (Red Hat) * if there are more than one tracepoint that uses the same format
4737496946aSSteven Rostedt (Red Hat) * for the proto, args, struct, assign and printk, and only the name
4747496946aSSteven Rostedt (Red Hat) * is different, it is highly recommended to use the DECLARE_EVENT_CLASS
4757496946aSSteven Rostedt (Red Hat) *
4767496946aSSteven Rostedt (Red Hat) * DECLARE_EVENT_CLASS() macro creates most of the functions for the
4777496946aSSteven Rostedt (Red Hat) * tracepoint. Then DEFINE_EVENT() is use to hook a tracepoint to those
4787496946aSSteven Rostedt (Red Hat) * functions. This DEFINE_EVENT() is an instance of the class and can
4797496946aSSteven Rostedt (Red Hat) * be enabled and disabled separately from other events (either TRACE_EVENT
4807496946aSSteven Rostedt (Red Hat) * or other DEFINE_EVENT()s).
4817496946aSSteven Rostedt (Red Hat) *
4827496946aSSteven Rostedt (Red Hat) * Note, TRACE_EVENT() itself is simply defined as:
4837496946aSSteven Rostedt (Red Hat) *
4847496946aSSteven Rostedt (Red Hat) * #define TRACE_EVENT(name, proto, args, tstruct, assign, printk) \
485f094a233SWei Yang * DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, printk); \
4867496946aSSteven Rostedt (Red Hat) * DEFINE_EVENT(name, name, proto, args)
4877496946aSSteven Rostedt (Red Hat) *
4887496946aSSteven Rostedt (Red Hat) * The DEFINE_EVENT() also can be declared with conditions and reg functions:
4897496946aSSteven Rostedt (Red Hat) *
4907496946aSSteven Rostedt (Red Hat) * DEFINE_EVENT_CONDITION(template, name, proto, args, cond);
4917496946aSSteven Rostedt (Red Hat) * DEFINE_EVENT_FN(template, name, proto, args, reg, unreg);
4927496946aSSteven Rostedt (Red Hat) */
4937496946aSSteven Rostedt (Red Hat) DECLARE_EVENT_CLASS(foo_template,
4947496946aSSteven Rostedt (Red Hat)
4957496946aSSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar),
4967496946aSSteven Rostedt (Red Hat)
4977496946aSSteven Rostedt (Red Hat) TP_ARGS(foo, bar),
4987496946aSSteven Rostedt (Red Hat)
4997496946aSSteven Rostedt (Red Hat) TP_STRUCT__entry(
5007496946aSSteven Rostedt (Red Hat) __string( foo, foo )
5017496946aSSteven Rostedt (Red Hat) __field( int, bar )
5027496946aSSteven Rostedt (Red Hat) ),
5037496946aSSteven Rostedt (Red Hat)
5047496946aSSteven Rostedt (Red Hat) TP_fast_assign(
5057496946aSSteven Rostedt (Red Hat) __assign_str(foo, foo);
5067496946aSSteven Rostedt (Red Hat) __entry->bar = bar;
5077496946aSSteven Rostedt (Red Hat) ),
5087496946aSSteven Rostedt (Red Hat)
5097496946aSSteven Rostedt (Red Hat) TP_printk("foo %s %d", __get_str(foo), __entry->bar)
5107496946aSSteven Rostedt (Red Hat) );
5117496946aSSteven Rostedt (Red Hat)
5127496946aSSteven Rostedt (Red Hat) /*
5137496946aSSteven Rostedt (Red Hat) * Here's a better way for the previous samples (except, the first
51427019975SJeremy Linton * example had more fields and could not be used here).
5157496946aSSteven Rostedt (Red Hat) */
5167496946aSSteven Rostedt (Red Hat) DEFINE_EVENT(foo_template, foo_with_template_simple,
5177496946aSSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar),
5187496946aSSteven Rostedt (Red Hat) TP_ARGS(foo, bar));
5197496946aSSteven Rostedt (Red Hat)
5207496946aSSteven Rostedt (Red Hat) DEFINE_EVENT_CONDITION(foo_template, foo_with_template_cond,
5217496946aSSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar),
5227496946aSSteven Rostedt (Red Hat) TP_ARGS(foo, bar),
5237496946aSSteven Rostedt (Red Hat) TP_CONDITION(!(bar % 8)));
5247496946aSSteven Rostedt (Red Hat)
5257496946aSSteven Rostedt (Red Hat)
5267496946aSSteven Rostedt (Red Hat) DEFINE_EVENT_FN(foo_template, foo_with_template_fn,
5277496946aSSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar),
5287496946aSSteven Rostedt (Red Hat) TP_ARGS(foo, bar),
5297496946aSSteven Rostedt (Red Hat) foo_bar_reg, foo_bar_unreg);
5307496946aSSteven Rostedt (Red Hat)
5317496946aSSteven Rostedt (Red Hat) /*
5327496946aSSteven Rostedt (Red Hat) * Anytime two events share basically the same values and have
5337496946aSSteven Rostedt (Red Hat) * the same output, use the DECLARE_EVENT_CLASS() and DEFINE_EVENT()
5347496946aSSteven Rostedt (Red Hat) * when ever possible.
5357496946aSSteven Rostedt (Red Hat) */
5367496946aSSteven Rostedt (Red Hat)
5377496946aSSteven Rostedt (Red Hat) /*
5387496946aSSteven Rostedt (Red Hat) * If the event is similar to the DECLARE_EVENT_CLASS, but you need
5397496946aSSteven Rostedt (Red Hat) * to have a different output, then use DEFINE_EVENT_PRINT() which
5407496946aSSteven Rostedt (Red Hat) * lets you override the TP_printk() of the class.
5417496946aSSteven Rostedt (Red Hat) */
5427496946aSSteven Rostedt (Red Hat)
5437496946aSSteven Rostedt (Red Hat) DEFINE_EVENT_PRINT(foo_template, foo_with_template_print,
5447496946aSSteven Rostedt (Red Hat) TP_PROTO(const char *foo, int bar),
5457496946aSSteven Rostedt (Red Hat) TP_ARGS(foo, bar),
5467496946aSSteven Rostedt (Red Hat) TP_printk("bar %s %d", __get_str(foo), __entry->bar));
5477496946aSSteven Rostedt (Red Hat)
548b466b133SMasami Hiramatsu /*
549b466b133SMasami Hiramatsu * There are yet another __rel_loc dynamic data attribute. If you
550b466b133SMasami Hiramatsu * use __rel_dynamic_array() and __rel_string() etc. macros, you
551b466b133SMasami Hiramatsu * can use this attribute. There is no difference from the viewpoint
552b466b133SMasami Hiramatsu * of functionality with/without 'rel' but the encoding is a bit
553b466b133SMasami Hiramatsu * different. This is expected to be used with user-space event,
554b466b133SMasami Hiramatsu * there is no reason that the kernel event use this, but only for
555b466b133SMasami Hiramatsu * testing.
556b466b133SMasami Hiramatsu */
557b466b133SMasami Hiramatsu
558b466b133SMasami Hiramatsu TRACE_EVENT(foo_rel_loc,
559b466b133SMasami Hiramatsu
5608230f27bSSteven Rostedt (Google) TP_PROTO(const char *foo, int bar, unsigned long *mask, const cpumask_t *cpus),
561b466b133SMasami Hiramatsu
5628230f27bSSteven Rostedt (Google) TP_ARGS(foo, bar, mask, cpus),
563b466b133SMasami Hiramatsu
564b466b133SMasami Hiramatsu TP_STRUCT__entry(
565b466b133SMasami Hiramatsu __rel_string( foo, foo )
566b466b133SMasami Hiramatsu __field( int, bar )
567b466b133SMasami Hiramatsu __rel_bitmask( bitmask,
568b466b133SMasami Hiramatsu BITS_PER_BYTE * sizeof(unsigned long) )
5698230f27bSSteven Rostedt (Google) __rel_cpumask( cpumask )
570b466b133SMasami Hiramatsu ),
571b466b133SMasami Hiramatsu
572b466b133SMasami Hiramatsu TP_fast_assign(
573b466b133SMasami Hiramatsu __assign_rel_str(foo, foo);
574b466b133SMasami Hiramatsu __entry->bar = bar;
575b466b133SMasami Hiramatsu __assign_rel_bitmask(bitmask, mask,
576b466b133SMasami Hiramatsu BITS_PER_BYTE * sizeof(unsigned long));
5778230f27bSSteven Rostedt (Google) __assign_rel_cpumask(cpumask, cpus);
578b466b133SMasami Hiramatsu ),
579b466b133SMasami Hiramatsu
5808230f27bSSteven Rostedt (Google) TP_printk("foo_rel_loc %s, %d, %s, %s", __get_rel_str(foo), __entry->bar,
5818230f27bSSteven Rostedt (Google) __get_rel_bitmask(bitmask),
5828230f27bSSteven Rostedt (Google) __get_rel_cpumask(cpumask))
583b466b133SMasami Hiramatsu );
5849cfe06f8SSteven Rostedt #endif
5859cfe06f8SSteven Rostedt
5869cfe06f8SSteven Rostedt /***** NOTICE! The #if protection ends here. *****/
5879cfe06f8SSteven Rostedt
5889cfe06f8SSteven Rostedt
5899cfe06f8SSteven Rostedt /*
5909cfe06f8SSteven Rostedt * There are several ways I could have done this. If I left out the
5919cfe06f8SSteven Rostedt * TRACE_INCLUDE_PATH, then it would default to the kernel source
5929cfe06f8SSteven Rostedt * include/trace/events directory.
5939cfe06f8SSteven Rostedt *
5949cfe06f8SSteven Rostedt * I could specify a path from the define_trace.h file back to this
5959cfe06f8SSteven Rostedt * file.
5969cfe06f8SSteven Rostedt *
5979cfe06f8SSteven Rostedt * #define TRACE_INCLUDE_PATH ../../samples/trace_events
5989cfe06f8SSteven Rostedt *
59944ad18e0SSteven Rostedt * But the safest and easiest way to simply make it use the directory
60044ad18e0SSteven Rostedt * that the file is in is to add in the Makefile:
6019cfe06f8SSteven Rostedt *
60244ad18e0SSteven Rostedt * CFLAGS_trace-events-sample.o := -I$(src)
6039cfe06f8SSteven Rostedt *
6049cfe06f8SSteven Rostedt * This will make sure the current path is part of the include
60544ad18e0SSteven Rostedt * structure for our file so that define_trace.h can find it.
6069cfe06f8SSteven Rostedt *
6079cfe06f8SSteven Rostedt * I could have made only the top level directory the include:
6089cfe06f8SSteven Rostedt *
6099cfe06f8SSteven Rostedt * CFLAGS_trace-events-sample.o := -I$(PWD)
6109cfe06f8SSteven Rostedt *
6119cfe06f8SSteven Rostedt * And then let the path to this directory be the TRACE_INCLUDE_PATH:
6129cfe06f8SSteven Rostedt *
6139cfe06f8SSteven Rostedt * #define TRACE_INCLUDE_PATH samples/trace_events
6149cfe06f8SSteven Rostedt *
61544ad18e0SSteven Rostedt * But then if something defines "samples" or "trace_events" as a macro
61644ad18e0SSteven Rostedt * then we could risk that being converted too, and give us an unexpected
6179cfe06f8SSteven Rostedt * result.
6189cfe06f8SSteven Rostedt */
6199cfe06f8SSteven Rostedt #undef TRACE_INCLUDE_PATH
62071e1c8acSSteven Rostedt #undef TRACE_INCLUDE_FILE
6219cfe06f8SSteven Rostedt #define TRACE_INCLUDE_PATH .
62271e1c8acSSteven Rostedt /*
62371e1c8acSSteven Rostedt * TRACE_INCLUDE_FILE is not needed if the filename and TRACE_SYSTEM are equal
62471e1c8acSSteven Rostedt */
62571e1c8acSSteven Rostedt #define TRACE_INCLUDE_FILE trace-events-sample
6269cfe06f8SSteven Rostedt #include <trace/define_trace.h>
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