diff options
Diffstat (limited to 'samples/trace_events/trace-events-sample.h')
| -rw-r--r-- | samples/trace_events/trace-events-sample.h | 94 |
1 files changed, 89 insertions, 5 deletions
diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h index 80b4a70315b6..1a92226202fc 100644 --- a/samples/trace_events/trace-events-sample.h +++ b/samples/trace_events/trace-events-sample.h @@ -141,6 +141,54 @@ * In most cases, the __assign_str() macro will take the same * parameters as the __string() macro had to declare the string. * + * __vstring: This is similar to __string() but instead of taking a + * dynamic length, it takes a variable list va_list 'va' variable. + * Some event callers already have a message from parameters saved + * in a va_list. Passing in the format and the va_list variable + * will save just enough on the ring buffer for that string. + * Note, the va variable used is a pointer to a va_list, not + * to the va_list directly. + * + * (va_list *va) + * + * __vstring(foo, fmt, va) is similar to: vsnprintf(foo, fmt, va) + * + * To assign the string, use the helper macro __assign_vstr(). + * + * __assign_vstr(foo, fmt, va); + * + * In most cases, the __assign_vstr() macro will take the same + * parameters as the __vstring() macro had to declare the string. + * Use __get_str() to retrieve the __vstring() just like it would for + * __string(). + * + * __string_len: This is a helper to a __dynamic_array, but it understands + * that the array has characters in it, and with the combined + * use of __assign_str_len(), it will allocate 'len' + 1 bytes + * in the ring buffer and add a '\0' to the string. This is + * useful if the string being saved has no terminating '\0' byte. + * It requires that the length of the string is known as it acts + * like a memcpy(). + * + * Declared with: + * + * __string_len(foo, bar, len) + * + * To assign this string, use the helper macro __assign_str_len(). + * + * __assign_str_len(foo, bar, len); + * + * Then len + 1 is allocated to the ring buffer, and a nul terminating + * byte is added. This is similar to: + * + * memcpy(__get_str(foo), bar, len); + * __get_str(foo)[len] = 0; + * + * The advantage of using this over __dynamic_array, is that it + * takes care of allocating the extra byte on the ring buffer + * for the '\0' terminating byte, and __get_str(foo) can be used + * in the TP_printk(). + * * __bitmask: This is another kind of __dynamic_array, but it expects * an array of longs, and the number of bits to parse. It takes * two parameters (name, nr_bits), where name is the name of the @@ -229,9 +277,10 @@ TRACE_DEFINE_ENUM(TRACE_SAMPLE_ZOO); TRACE_EVENT(foo_bar, TP_PROTO(const char *foo, int bar, const int *lst, - const char *string, const struct cpumask *mask), + const char *string, const struct cpumask *mask, + const char *fmt, va_list *va), - TP_ARGS(foo, bar, lst, string, mask), + TP_ARGS(foo, bar, lst, string, mask, fmt, va), TP_STRUCT__entry( __array( char, foo, 10 ) @@ -239,6 +288,7 @@ TRACE_EVENT(foo_bar, __dynamic_array(int, list, __length_of(lst)) __string( str, string ) __bitmask( cpus, num_possible_cpus() ) + __vstring( vstr, fmt, va ) ), TP_fast_assign( @@ -247,10 +297,11 @@ TRACE_EVENT(foo_bar, memcpy(__get_dynamic_array(list), lst, __length_of(lst) * sizeof(int)); __assign_str(str, string); + __assign_vstr(vstr, fmt, va); __assign_bitmask(cpus, cpumask_bits(mask), num_possible_cpus()); ), - TP_printk("foo %s %d %s %s %s %s (%s)", __entry->foo, __entry->bar, + TP_printk("foo %s %d %s %s %s %s (%s) %s", __entry->foo, __entry->bar, /* * Notice here the use of some helper functions. This includes: @@ -294,7 +345,7 @@ TRACE_EVENT(foo_bar, __print_array(__get_dynamic_array(list), __get_dynamic_array_len(list) / sizeof(int), sizeof(int)), - __get_str(str), __get_bitmask(cpus)) + __get_str(str), __get_bitmask(cpus), __get_str(vstr)) ); /* @@ -416,7 +467,7 @@ TRACE_EVENT_FN(foo_bar_with_fn, * Note, TRACE_EVENT() itself is simply defined as: * * #define TRACE_EVENT(name, proto, args, tstruct, assign, printk) \ - * DEFINE_EVENT_CLASS(name, proto, args, tstruct, assign, printk); \ + * DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, printk); \ * DEFINE_EVENT(name, name, proto, args) * * The DEFINE_EVENT() also can be declared with conditions and reg functions: @@ -479,6 +530,39 @@ DEFINE_EVENT_PRINT(foo_template, foo_with_template_print, TP_ARGS(foo, bar), TP_printk("bar %s %d", __get_str(foo), __entry->bar)); +/* + * There are yet another __rel_loc dynamic data attribute. If you + * use __rel_dynamic_array() and __rel_string() etc. macros, you + * can use this attribute. There is no difference from the viewpoint + * of functionality with/without 'rel' but the encoding is a bit + * different. This is expected to be used with user-space event, + * there is no reason that the kernel event use this, but only for + * testing. + */ + +TRACE_EVENT(foo_rel_loc, + + TP_PROTO(const char *foo, int bar, unsigned long *mask), + + TP_ARGS(foo, bar, mask), + + TP_STRUCT__entry( + __rel_string( foo, foo ) + __field( int, bar ) + __rel_bitmask( bitmask, + BITS_PER_BYTE * sizeof(unsigned long) ) + ), + + TP_fast_assign( + __assign_rel_str(foo, foo); + __entry->bar = bar; + __assign_rel_bitmask(bitmask, mask, + BITS_PER_BYTE * sizeof(unsigned long)); + ), + + TP_printk("foo_rel_loc %s, %d, %s", __get_rel_str(foo), __entry->bar, + __get_rel_bitmask(bitmask)) +); #endif /***** NOTICE! The #if protection ends here. *****/ |