1*4882a593Smuzhiyunlibtraceevent(3) 2*4882a593Smuzhiyun================ 3*4882a593Smuzhiyun 4*4882a593SmuzhiyunNAME 5*4882a593Smuzhiyun---- 6*4882a593Smuzhiyuntep_print_event - Writes event information into a trace sequence. 7*4882a593Smuzhiyun 8*4882a593SmuzhiyunSYNOPSIS 9*4882a593Smuzhiyun-------- 10*4882a593Smuzhiyun[verse] 11*4882a593Smuzhiyun-- 12*4882a593Smuzhiyun*#include <event-parse.h>* 13*4882a593Smuzhiyun*#include <trace-seq.h>* 14*4882a593Smuzhiyun 15*4882a593Smuzhiyunvoid *tep_print_event*(struct tep_handle pass:[*]_tep_, struct trace_seqpass:[*]_s_, struct tep_record pass:[*]_record_, const char pass:[*]_fmt_, _..._) 16*4882a593Smuzhiyun-- 17*4882a593Smuzhiyun 18*4882a593SmuzhiyunDESCRIPTION 19*4882a593Smuzhiyun----------- 20*4882a593Smuzhiyun 21*4882a593SmuzhiyunThe _tep_print_event()_ function parses the event information of the given 22*4882a593Smuzhiyun_record_ and writes it into the trace sequence _s_, according to the format 23*4882a593Smuzhiyunstring _fmt_. The desired information is specified after the format string. 24*4882a593SmuzhiyunThe _fmt_ is printf-like format string, following arguments are supported: 25*4882a593Smuzhiyun[verse] 26*4882a593Smuzhiyun-- 27*4882a593Smuzhiyun TEP_PRINT_PID, "%d" - PID of the event. 28*4882a593Smuzhiyun TEP_PRINT_CPU, "%d" - Event CPU. 29*4882a593Smuzhiyun TEP_PRINT_COMM, "%s" - Event command string. 30*4882a593Smuzhiyun TEP_PRINT_NAME, "%s" - Event name. 31*4882a593Smuzhiyun TEP_PRINT_LATENCY, "%s" - Latency of the event. It prints 4 or more 32*4882a593Smuzhiyun fields - interrupt state, scheduling state, 33*4882a593Smuzhiyun current context, and preemption count. 34*4882a593Smuzhiyun Field 1 is the interrupt enabled state: 35*4882a593Smuzhiyun d : Interrupts are disabled 36*4882a593Smuzhiyun . : Interrupts are enabled 37*4882a593Smuzhiyun X : The architecture does not support this 38*4882a593Smuzhiyun information 39*4882a593Smuzhiyun Field 2 is the "need resched" state. 40*4882a593Smuzhiyun N : The task is set to call the scheduler when 41*4882a593Smuzhiyun possible, as another higher priority task 42*4882a593Smuzhiyun may need to be scheduled in. 43*4882a593Smuzhiyun . : The task is not set to call the scheduler. 44*4882a593Smuzhiyun Field 3 is the context state. 45*4882a593Smuzhiyun . : Normal context 46*4882a593Smuzhiyun s : Soft interrupt context 47*4882a593Smuzhiyun h : Hard interrupt context 48*4882a593Smuzhiyun H : Hard interrupt context which triggered 49*4882a593Smuzhiyun during soft interrupt context. 50*4882a593Smuzhiyun z : NMI context 51*4882a593Smuzhiyun Z : NMI context which triggered during hard 52*4882a593Smuzhiyun interrupt context 53*4882a593Smuzhiyun Field 4 is the preemption count. 54*4882a593Smuzhiyun . : The preempt count is zero. 55*4882a593Smuzhiyun On preemptible kernels (where the task can be scheduled 56*4882a593Smuzhiyun out in arbitrary locations while in kernel context), the 57*4882a593Smuzhiyun preempt count, when non zero, will prevent the kernel 58*4882a593Smuzhiyun from scheduling out the current task. The preempt count 59*4882a593Smuzhiyun number is displayed when it is not zero. 60*4882a593Smuzhiyun Depending on the kernel, it may show other fields 61*4882a593Smuzhiyun (lock depth, or migration disabled, which are unique to 62*4882a593Smuzhiyun specialized kernels). 63*4882a593Smuzhiyun TEP_PRINT_TIME, %d - event time stamp. A divisor and precision can be 64*4882a593Smuzhiyun specified as part of this format string: 65*4882a593Smuzhiyun "%precision.divisord". Example: 66*4882a593Smuzhiyun "%3.1000d" - divide the time by 1000 and print the first 67*4882a593Smuzhiyun 3 digits before the dot. Thus, the time stamp 68*4882a593Smuzhiyun "123456000" will be printed as "123.456" 69*4882a593Smuzhiyun TEP_PRINT_INFO, "%s" - event information. 70*4882a593Smuzhiyun TEP_PRINT_INFO_RAW, "%s" - event information, in raw format. 71*4882a593Smuzhiyun 72*4882a593Smuzhiyun-- 73*4882a593SmuzhiyunEXAMPLE 74*4882a593Smuzhiyun------- 75*4882a593Smuzhiyun[source,c] 76*4882a593Smuzhiyun-- 77*4882a593Smuzhiyun#include <event-parse.h> 78*4882a593Smuzhiyun#include <trace-seq.h> 79*4882a593Smuzhiyun... 80*4882a593Smuzhiyunstruct trace_seq seq; 81*4882a593Smuzhiyuntrace_seq_init(&seq); 82*4882a593Smuzhiyunstruct tep_handle *tep = tep_alloc(); 83*4882a593Smuzhiyun... 84*4882a593Smuzhiyunvoid print_my_event(struct tep_record *record) 85*4882a593Smuzhiyun{ 86*4882a593Smuzhiyun trace_seq_reset(&seq); 87*4882a593Smuzhiyun tep_print_event(tep, s, record, "%16s-%-5d [%03d] %s %6.1000d %s %s", 88*4882a593Smuzhiyun TEP_PRINT_COMM, TEP_PRINT_PID, TEP_PRINT_CPU, 89*4882a593Smuzhiyun TEP_PRINT_LATENCY, TEP_PRINT_TIME, TEP_PRINT_NAME, 90*4882a593Smuzhiyun TEP_PRINT_INFO); 91*4882a593Smuzhiyun} 92*4882a593Smuzhiyun... 93*4882a593Smuzhiyun-- 94*4882a593Smuzhiyun 95*4882a593SmuzhiyunFILES 96*4882a593Smuzhiyun----- 97*4882a593Smuzhiyun[verse] 98*4882a593Smuzhiyun-- 99*4882a593Smuzhiyun*event-parse.h* 100*4882a593Smuzhiyun Header file to include in order to have access to the library APIs. 101*4882a593Smuzhiyun*trace-seq.h* 102*4882a593Smuzhiyun Header file to include in order to have access to trace sequences related APIs. 103*4882a593Smuzhiyun Trace sequences are used to allow a function to call several other functions 104*4882a593Smuzhiyun to create a string of data to use. 105*4882a593Smuzhiyun*-ltraceevent* 106*4882a593Smuzhiyun Linker switch to add when building a program that uses the library. 107*4882a593Smuzhiyun-- 108*4882a593Smuzhiyun 109*4882a593SmuzhiyunSEE ALSO 110*4882a593Smuzhiyun-------- 111*4882a593Smuzhiyun_libtraceevent(3)_, _trace-cmd(1)_ 112*4882a593Smuzhiyun 113*4882a593SmuzhiyunAUTHOR 114*4882a593Smuzhiyun------ 115*4882a593Smuzhiyun[verse] 116*4882a593Smuzhiyun-- 117*4882a593Smuzhiyun*Steven Rostedt* <rostedt@goodmis.org>, author of *libtraceevent*. 118*4882a593Smuzhiyun*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>, author of this man page. 119*4882a593Smuzhiyun-- 120*4882a593SmuzhiyunREPORTING BUGS 121*4882a593Smuzhiyun-------------- 122*4882a593SmuzhiyunReport bugs to <linux-trace-devel@vger.kernel.org> 123*4882a593Smuzhiyun 124*4882a593SmuzhiyunLICENSE 125*4882a593Smuzhiyun------- 126*4882a593Smuzhiyunlibtraceevent is Free Software licensed under the GNU LGPL 2.1 127*4882a593Smuzhiyun 128*4882a593SmuzhiyunRESOURCES 129*4882a593Smuzhiyun--------- 130*4882a593Smuzhiyunhttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 131