From 770cb24345c0f6e0d47bd2b94aa6d67bea6f8b54 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 5 Mar 2009 21:35:29 -0500 Subject: tracing: add format files for ftrace default entries Impact: allow user apps to read binary format of basic ftrace entries Currently, only defined raw events export their formats so a binary reader can parse them. There's no reason that the default ftrace entries can't export their formats. This patch adds a subsystem called "ftrace" in the events directory that includes the ftrace entries for basic ftrace recorded items. These only have three files in the events directory: type : printf available_types : printf format : format for the event entry For example: # cat /debug/tracing/events/ftrace/wakeup/format name: wakeup ID: 3 format: field:unsigned char type; offset:0; size:1; field:unsigned char flags; offset:1; size:1; field:unsigned char preempt_count; offset:2; size:1; field:int pid; offset:4; size:4; field:int tgid; offset:8; size:4; field:unsigned int prev_pid; offset:12; size:4; field:unsigned char prev_prio; offset:16; size:1; field:unsigned char prev_state; offset:17; size:1; field:unsigned int next_pid; offset:20; size:4; field:unsigned char next_prio; offset:24; size:1; field:unsigned char next_state; offset:25; size:1; field:unsigned int next_cpu; offset:28; size:4; print fmt: "%u:%u:%u ==+ %u:%u:%u [%03u]" Signed-off-by: Steven Rostedt --- kernel/trace/trace_export.c | 81 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 kernel/trace/trace_export.c (limited to 'kernel/trace/trace_export.c') diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c new file mode 100644 index 000000000000..0fb7be73e31c --- /dev/null +++ b/kernel/trace/trace_export.c @@ -0,0 +1,81 @@ +/* + * trace_export.c - export basic ftrace utilities to user space + * + * Copyright (C) 2009 Steven Rostedt + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "trace_output.h" + +#include "trace_format.h" + +#undef TRACE_FIELD_ZERO_CHAR +#define TRACE_FIELD_ZERO_CHAR(item) \ + ret = trace_seq_printf(s, "\tfield: char " #item ";\t" \ + "offset:%lu;\tsize:0;\n", \ + offsetof(typeof(field), item)); \ + if (!ret) \ + return 0; + + +#undef TPRAWFMT +#define TPRAWFMT(args...) args + +#undef TRACE_EVENT_FORMAT +#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ +static int \ +ftrace_format_##call(struct trace_seq *s) \ +{ \ + struct args field; \ + int ret; \ + \ + tstruct; \ + \ + trace_seq_printf(s, "\nprint fmt: \"%s\"\n", tpfmt); \ + \ + return ret; \ +} + +#include "trace_event_types.h" + +#undef TRACE_ZERO_CHAR +#define TRACE_ZERO_CHAR(arg) + +#undef TRACE_FIELD +#define TRACE_FIELD(type, item, assign)\ + entry->item = assign; + +#undef TRACE_FIELD +#define TRACE_FIELD(type, item, assign)\ + entry->item = assign; + +#undef TPCMD +#define TPCMD(cmd...) cmd + +#undef TRACE_ENTRY +#define TRACE_ENTRY entry + +#undef TRACE_FIELD_SPECIAL +#define TRACE_FIELD_SPECIAL(type_item, item, cmd) \ + cmd; + +#undef TRACE_EVENT_FORMAT +#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ + \ +static struct ftrace_event_call __used \ +__attribute__((__aligned__(4))) \ +__attribute__((section("_ftrace_events"))) event_##call = { \ + .name = #call, \ + .id = proto, \ + .system = __stringify(TRACE_SYSTEM), \ + .show_format = ftrace_format_##call, \ +} +#include "trace_event_types.h" -- cgit v1.2.3 From 156b5f172a64103bcb13b6d26288388b9019caa3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 6 Mar 2009 10:50:53 -0500 Subject: tracing: typecast sizeof and offsetof to unsigned int Impact: fix compiler warnings On x86_64 sizeof and offsetof are treated as long, where as on x86_32 they are int. This patch typecasts them to unsigned int to avoid one arch giving warnings while the other does not. Reported-by: Ingo Molnar Signed-off-by: Steven Rostedt --- kernel/trace/trace_export.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel/trace/trace_export.c') diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index 0fb7be73e31c..7162ab49d05d 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -18,11 +18,11 @@ #include "trace_format.h" #undef TRACE_FIELD_ZERO_CHAR -#define TRACE_FIELD_ZERO_CHAR(item) \ - ret = trace_seq_printf(s, "\tfield: char " #item ";\t" \ - "offset:%lu;\tsize:0;\n", \ - offsetof(typeof(field), item)); \ - if (!ret) \ +#define TRACE_FIELD_ZERO_CHAR(item) \ + ret = trace_seq_printf(s, "\tfield: char " #item ";\t" \ + "offset:%u;\tsize:0;\n", \ + (unsigned int)offsetof(typeof(field), item)); \ + if (!ret) \ return 0; -- cgit v1.2.3 From 2939b0469d04ba9ac791aca9a81625d7eb50662b Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 9 Mar 2009 15:47:18 -0400 Subject: tracing: replace TP with TP_ Impact: clean up The macros TPPROTO, TPARGS, TPFMT, TPRAWFMT, and TPCMD all look a bit ugly. This patch adds an underscore to their names. Signed-off-by: Steven Rostedt --- kernel/trace/trace_export.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel/trace/trace_export.c') diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index 7162ab49d05d..e62bc10f8103 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -26,8 +26,8 @@ return 0; -#undef TPRAWFMT -#define TPRAWFMT(args...) args +#undef TP_RAW_FMT +#define TP_RAW_FMT(args...) args #undef TRACE_EVENT_FORMAT #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ @@ -57,8 +57,8 @@ ftrace_format_##call(struct trace_seq *s) \ #define TRACE_FIELD(type, item, assign)\ entry->item = assign; -#undef TPCMD -#define TPCMD(cmd...) cmd +#undef TP_CMD +#define TP_CMD(cmd...) cmd #undef TRACE_ENTRY #define TRACE_ENTRY entry -- cgit v1.2.3 From da4d03020c2af32f73e8bfbab0a66620d85bb9bb Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 9 Mar 2009 17:14:30 -0400 Subject: tracing: new format for specialized trace points Impact: clean up and enhancement The TRACE_EVENT_FORMAT macro looks quite ugly and is limited in its ability to save data as well as to print the record out. Working with Ingo Molnar, we came up with a new format that is much more pleasing to the eye of C developers. This new macro is more C style than the old macro, and is more obvious to what it does. Here's the example. The only updated macro in this patch is the sched_switch trace point. The old method looked like this: TRACE_EVENT_FORMAT(sched_switch, TP_PROTO(struct rq *rq, struct task_struct *prev, struct task_struct *next), TP_ARGS(rq, prev, next), TP_FMT("task %s:%d ==> %s:%d", prev->comm, prev->pid, next->comm, next->pid), TRACE_STRUCT( TRACE_FIELD(pid_t, prev_pid, prev->pid) TRACE_FIELD(int, prev_prio, prev->prio) TRACE_FIELD_SPECIAL(char next_comm[TASK_COMM_LEN], next_comm, TP_CMD(memcpy(TRACE_ENTRY->next_comm, next->comm, TASK_COMM_LEN))) TRACE_FIELD(pid_t, next_pid, next->pid) TRACE_FIELD(int, next_prio, next->prio) ), TP_RAW_FMT("prev %d:%d ==> next %s:%d:%d") ); The above method is hard to read and requires two format fields. The new method: /* * Tracepoint for task switches, performed by the scheduler: * * (NOTE: the 'rq' argument is not used by generic trace events, * but used by the latency tracer plugin. ) */ TRACE_EVENT(sched_switch, TP_PROTO(struct rq *rq, struct task_struct *prev, struct task_struct *next), TP_ARGS(rq, prev, next), TP_STRUCT__entry( __array( char, prev_comm, TASK_COMM_LEN ) __field( pid_t, prev_pid ) __field( int, prev_prio ) __array( char, next_comm, TASK_COMM_LEN ) __field( pid_t, next_pid ) __field( int, next_prio ) ), TP_printk("task %s:%d [%d] ==> %s:%d [%d]", __entry->prev_comm, __entry->prev_pid, __entry->prev_prio, __entry->next_comm, __entry->next_pid, __entry->next_prio), TP_fast_assign( memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); __entry->prev_pid = prev->pid; __entry->prev_prio = prev->prio; memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN); __entry->next_pid = next->pid; __entry->next_prio = next->prio; ) ); This macro is called TRACE_EVENT, it is broken up into 5 parts: TP_PROTO: the proto type of the trace point TP_ARGS: the arguments of the trace point TP_STRUCT_entry: the structure layout of the entry in the ring buffer TP_printk: the printk format TP_fast_assign: the method used to write the entry into the ring buffer The structure is the definition of how the event will be saved in the ring buffer. The printk is used by the internal tracing in case of an oops, and the kernel needs to print out the format of the record to the console. This the TP_printk gives a means to show the records in a human readable format. It is also used to print out the data from the trace file. The TP_fast_assign is executed directly. It is basically like a C function, where the __entry is the handle to the record. Signed-off-by: Steven Rostedt --- kernel/trace/trace_export.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace_export.c') diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index e62bc10f8103..23ae78430d58 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -15,7 +15,28 @@ #include "trace_output.h" -#include "trace_format.h" + +#undef TRACE_STRUCT +#define TRACE_STRUCT(args...) args + +#undef TRACE_FIELD +#define TRACE_FIELD(type, item, assign) \ + ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t" \ + "offset:%u;\tsize:%u;\n", \ + (unsigned int)offsetof(typeof(field), item), \ + (unsigned int)sizeof(field.item)); \ + if (!ret) \ + return 0; + + +#undef TRACE_FIELD_SPECIAL +#define TRACE_FIELD_SPECIAL(type_item, item, cmd) \ + ret = trace_seq_printf(s, "\tfield special:" #type_item ";\t" \ + "offset:%u;\tsize:%u;\n", \ + (unsigned int)offsetof(typeof(field), item), \ + (unsigned int)sizeof(field.item)); \ + if (!ret) \ + return 0; #undef TRACE_FIELD_ZERO_CHAR #define TRACE_FIELD_ZERO_CHAR(item) \ -- cgit v1.2.3 From ef18012b248b47ec9a12c3a83ca5e99782d39c5d Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 10 Mar 2009 14:10:56 -0400 Subject: tracing: remove funky whitespace in the trace code Impact: clean up There existed a lot of 's in the tracing code. This patch removes them. Signed-off-by: Steven Rostedt --- kernel/trace/trace_export.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace/trace_export.c') diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index 23ae78430d58..4d9952d3df50 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -94,7 +94,7 @@ ftrace_format_##call(struct trace_seq *s) \ static struct ftrace_event_call __used \ __attribute__((__aligned__(4))) \ __attribute__((section("_ftrace_events"))) event_##call = { \ - .name = #call, \ + .name = #call, \ .id = proto, \ .system = __stringify(TRACE_SYSTEM), \ .show_format = ftrace_format_##call, \ -- cgit v1.2.3 From 1bbe2a83ab68e5cf8c66c372c7cb3b51910c2cfe Mon Sep 17 00:00:00 2001 From: Zhaolei Date: Fri, 3 Apr 2009 18:24:46 +0800 Subject: ftrace: Correct a text align for event format output If we cat debugfs/tracing/events/ftrace/bprint/format, we'll see: name: bprint ID: 6 format: field:unsigned char common_type; offset:0; size:1; field:unsigned char common_flags; offset:1; size:1; field:unsigned char common_preempt_count; offset:2; size:1; field:int common_pid; offset:4; size:4; field:int common_tgid; offset:8; size:4; field:unsigned long ip; offset:12; size:4; field:char * fmt; offset:16; size:4; field: char buf; offset:20; size:0; print fmt: "%08lx (%d) fmt:%p %s" There is an inconsistent blank before char buf. Signed-off-by: Zhao Lei LKML-Reference: <49D5E3EE.70201@cn.fujitsu.com> Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_export.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace/trace_export.c') diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index 4d9952d3df50..07a22c33ebf3 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -40,7 +40,7 @@ #undef TRACE_FIELD_ZERO_CHAR #define TRACE_FIELD_ZERO_CHAR(item) \ - ret = trace_seq_printf(s, "\tfield: char " #item ";\t" \ + ret = trace_seq_printf(s, "\tfield:char " #item ";\t" \ "offset:%u;\tsize:0;\n", \ (unsigned int)offsetof(typeof(field), item)); \ if (!ret) \ -- cgit v1.2.3