287b6e68ca
Impact: feature
This patch sets a C-like output for the function graph tracing.
For this aim, we now call two handler for each function: one on the entry
and one other on return. This way we can draw a well-ordered call stack.
The pid of the previous trace is loosely stored to be compared against
the one of the current trace to see if there were a context switch.
Without this little feature, the call tree would seem broken at
some locations.
We could use the sched_tracer to capture these sched_events but this
way of processing is much more simpler.
2 spaces have been chosen for indentation to fit the screen while deep
calls. The time of execution in nanosecs is printed just after closed
braces, it seems more easy this way to find the corresponding function.
If the time was printed as a first column, it would be not so easy to
find the corresponding function if it is called on a deep depth.
I plan to output the return value but on 32 bits CPU, the return value
can be 32 or 64, and its difficult to guess on which case we are.
I don't know what would be the better solution on X86-32: only print
eax (low-part) or even edx (high-part).
Actually it's thee same problem when a function return a 8 bits value, the
high part of eax could contain junk values...
Here is an example of trace:
sys_read() {
fget_light() {
} 526
vfs_read() {
rw_verify_area() {
security_file_permission() {
cap_file_permission() {
} 519
} 1564
} 2640
do_sync_read() {
pipe_read() {
__might_sleep() {
} 511
pipe_wait() {
prepare_to_wait() {
} 760
deactivate_task() {
dequeue_task() {
dequeue_task_fair() {
dequeue_entity() {
update_curr() {
update_min_vruntime() {
} 504
} 1587
clear_buddies() {
} 512
add_cfs_task_weight() {
} 519
update_min_vruntime() {
} 511
} 5602
dequeue_entity() {
update_curr() {
update_min_vruntime() {
} 496
} 1631
clear_buddies() {
} 496
update_min_vruntime() {
} 527
} 4580
hrtick_update() {
hrtick_start_fair() {
} 488
} 1489
} 13700
} 14949
} 16016
msecs_to_jiffies() {
} 496
put_prev_task_fair() {
} 504
pick_next_task_fair() {
} 489
pick_next_task_rt() {
} 496
pick_next_task_fair() {
} 489
pick_next_task_idle() {
} 489
------------8<---------- thread 4 ------------8<----------
finish_task_switch() {
} 1203
do_softirq() {
__do_softirq() {
__local_bh_disable() {
} 669
rcu_process_callbacks() {
__rcu_process_callbacks() {
cpu_quiet() {
rcu_start_batch() {
} 503
} 1647
} 3128
__rcu_process_callbacks() {
} 542
} 5362
_local_bh_enable() {
} 587
} 8880
} 9986
kthread_should_stop() {
} 669
deactivate_task() {
dequeue_task() {
dequeue_task_fair() {
dequeue_entity() {
update_curr() {
calc_delta_mine() {
} 511
update_min_vruntime() {
} 511
} 2813
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
616 lines
17 KiB
C
616 lines
17 KiB
C
#ifndef _LINUX_KERNEL_TRACE_H
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#define _LINUX_KERNEL_TRACE_H
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#include <linux/fs.h>
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#include <asm/atomic.h>
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#include <linux/sched.h>
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#include <linux/clocksource.h>
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#include <linux/ring_buffer.h>
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#include <linux/mmiotrace.h>
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#include <linux/ftrace.h>
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#include <trace/boot.h>
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enum trace_type {
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__TRACE_FIRST_TYPE = 0,
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TRACE_FN,
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TRACE_CTX,
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TRACE_WAKE,
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TRACE_CONT,
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TRACE_STACK,
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TRACE_PRINT,
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TRACE_SPECIAL,
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TRACE_MMIO_RW,
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TRACE_MMIO_MAP,
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TRACE_BRANCH,
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TRACE_BOOT_CALL,
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TRACE_BOOT_RET,
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TRACE_GRAPH_RET,
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TRACE_GRAPH_ENT,
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TRACE_USER_STACK,
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TRACE_BTS,
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__TRACE_LAST_TYPE
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};
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/*
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* The trace entry - the most basic unit of tracing. This is what
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* is printed in the end as a single line in the trace output, such as:
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*
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* bash-15816 [01] 235.197585: idle_cpu <- irq_enter
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*/
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struct trace_entry {
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unsigned char type;
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unsigned char cpu;
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unsigned char flags;
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unsigned char preempt_count;
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int pid;
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int tgid;
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};
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/*
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* Function trace entry - function address and parent function addres:
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*/
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struct ftrace_entry {
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struct trace_entry ent;
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unsigned long ip;
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unsigned long parent_ip;
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};
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/* Function call entry */
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struct ftrace_graph_ent_entry {
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struct trace_entry ent;
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struct ftrace_graph_ent graph_ent;
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};
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/* Function return entry */
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struct ftrace_graph_ret_entry {
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struct trace_entry ent;
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struct ftrace_graph_ret ret;
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};
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extern struct tracer boot_tracer;
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/*
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* Context switch trace entry - which task (and prio) we switched from/to:
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*/
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struct ctx_switch_entry {
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struct trace_entry ent;
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unsigned int prev_pid;
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unsigned char prev_prio;
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unsigned char prev_state;
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unsigned int next_pid;
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unsigned char next_prio;
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unsigned char next_state;
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unsigned int next_cpu;
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};
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/*
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* Special (free-form) trace entry:
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*/
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struct special_entry {
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struct trace_entry ent;
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unsigned long arg1;
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unsigned long arg2;
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unsigned long arg3;
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};
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/*
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* Stack-trace entry:
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*/
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#define FTRACE_STACK_ENTRIES 8
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struct stack_entry {
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struct trace_entry ent;
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unsigned long caller[FTRACE_STACK_ENTRIES];
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};
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struct userstack_entry {
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struct trace_entry ent;
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unsigned long caller[FTRACE_STACK_ENTRIES];
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};
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/*
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* ftrace_printk entry:
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*/
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struct print_entry {
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struct trace_entry ent;
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unsigned long ip;
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char buf[];
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};
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#define TRACE_OLD_SIZE 88
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struct trace_field_cont {
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unsigned char type;
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/* Temporary till we get rid of this completely */
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char buf[TRACE_OLD_SIZE - 1];
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};
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struct trace_mmiotrace_rw {
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struct trace_entry ent;
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struct mmiotrace_rw rw;
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};
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struct trace_mmiotrace_map {
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struct trace_entry ent;
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struct mmiotrace_map map;
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};
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struct trace_boot_call {
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struct trace_entry ent;
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struct boot_trace_call boot_call;
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};
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struct trace_boot_ret {
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struct trace_entry ent;
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struct boot_trace_ret boot_ret;
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};
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#define TRACE_FUNC_SIZE 30
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#define TRACE_FILE_SIZE 20
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struct trace_branch {
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struct trace_entry ent;
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unsigned line;
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char func[TRACE_FUNC_SIZE+1];
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char file[TRACE_FILE_SIZE+1];
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char correct;
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};
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struct bts_entry {
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struct trace_entry ent;
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unsigned long from;
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unsigned long to;
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};
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/*
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* trace_flag_type is an enumeration that holds different
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* states when a trace occurs. These are:
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* IRQS_OFF - interrupts were disabled
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* IRQS_NOSUPPORT - arch does not support irqs_disabled_flags
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* NEED_RESCED - reschedule is requested
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* HARDIRQ - inside an interrupt handler
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* SOFTIRQ - inside a softirq handler
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* CONT - multiple entries hold the trace item
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*/
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enum trace_flag_type {
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TRACE_FLAG_IRQS_OFF = 0x01,
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TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
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TRACE_FLAG_NEED_RESCHED = 0x04,
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TRACE_FLAG_HARDIRQ = 0x08,
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TRACE_FLAG_SOFTIRQ = 0x10,
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TRACE_FLAG_CONT = 0x20,
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};
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#define TRACE_BUF_SIZE 1024
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/*
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* The CPU trace array - it consists of thousands of trace entries
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* plus some other descriptor data: (for example which task started
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* the trace, etc.)
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*/
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struct trace_array_cpu {
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atomic_t disabled;
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/* these fields get copied into max-trace: */
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unsigned long trace_idx;
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unsigned long overrun;
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unsigned long saved_latency;
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unsigned long critical_start;
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unsigned long critical_end;
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unsigned long critical_sequence;
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unsigned long nice;
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unsigned long policy;
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unsigned long rt_priority;
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cycle_t preempt_timestamp;
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pid_t pid;
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uid_t uid;
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char comm[TASK_COMM_LEN];
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};
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struct trace_iterator;
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/*
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* The trace array - an array of per-CPU trace arrays. This is the
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* highest level data structure that individual tracers deal with.
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* They have on/off state as well:
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*/
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struct trace_array {
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struct ring_buffer *buffer;
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unsigned long entries;
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int cpu;
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cycle_t time_start;
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struct task_struct *waiter;
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struct trace_array_cpu *data[NR_CPUS];
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};
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#define FTRACE_CMP_TYPE(var, type) \
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__builtin_types_compatible_p(typeof(var), type *)
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#undef IF_ASSIGN
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#define IF_ASSIGN(var, entry, etype, id) \
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if (FTRACE_CMP_TYPE(var, etype)) { \
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var = (typeof(var))(entry); \
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WARN_ON(id && (entry)->type != id); \
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break; \
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}
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/* Will cause compile errors if type is not found. */
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extern void __ftrace_bad_type(void);
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/*
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* The trace_assign_type is a verifier that the entry type is
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* the same as the type being assigned. To add new types simply
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* add a line with the following format:
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*
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* IF_ASSIGN(var, ent, type, id);
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*
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* Where "type" is the trace type that includes the trace_entry
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* as the "ent" item. And "id" is the trace identifier that is
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* used in the trace_type enum.
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*
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* If the type can have more than one id, then use zero.
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*/
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#define trace_assign_type(var, ent) \
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do { \
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IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
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IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
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IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
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IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
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IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
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IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
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IF_ASSIGN(var, ent, struct special_entry, 0); \
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IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
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TRACE_MMIO_RW); \
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IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
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TRACE_MMIO_MAP); \
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IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
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IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
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IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
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IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \
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TRACE_GRAPH_ENT); \
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IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \
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TRACE_GRAPH_RET); \
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IF_ASSIGN(var, ent, struct bts_entry, TRACE_BTS);\
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__ftrace_bad_type(); \
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} while (0)
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/* Return values for print_line callback */
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enum print_line_t {
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TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */
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TRACE_TYPE_HANDLED = 1,
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TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */
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};
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/*
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* An option specific to a tracer. This is a boolean value.
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* The bit is the bit index that sets its value on the
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* flags value in struct tracer_flags.
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*/
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struct tracer_opt {
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const char *name; /* Will appear on the trace_options file */
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u32 bit; /* Mask assigned in val field in tracer_flags */
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};
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/*
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* The set of specific options for a tracer. Your tracer
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* have to set the initial value of the flags val.
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*/
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struct tracer_flags {
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u32 val;
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struct tracer_opt *opts;
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};
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/* Makes more easy to define a tracer opt */
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#define TRACER_OPT(s, b) .name = #s, .bit = b
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/*
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* A specific tracer, represented by methods that operate on a trace array:
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*/
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struct tracer {
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const char *name;
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/* Your tracer should raise a warning if init fails */
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int (*init)(struct trace_array *tr);
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void (*reset)(struct trace_array *tr);
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void (*start)(struct trace_array *tr);
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void (*stop)(struct trace_array *tr);
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void (*open)(struct trace_iterator *iter);
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void (*pipe_open)(struct trace_iterator *iter);
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void (*close)(struct trace_iterator *iter);
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ssize_t (*read)(struct trace_iterator *iter,
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struct file *filp, char __user *ubuf,
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size_t cnt, loff_t *ppos);
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#ifdef CONFIG_FTRACE_STARTUP_TEST
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int (*selftest)(struct tracer *trace,
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struct trace_array *tr);
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#endif
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void (*print_header)(struct seq_file *m);
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enum print_line_t (*print_line)(struct trace_iterator *iter);
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/* If you handled the flag setting, return 0 */
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int (*set_flag)(u32 old_flags, u32 bit, int set);
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struct tracer *next;
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int print_max;
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struct tracer_flags *flags;
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};
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struct trace_seq {
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unsigned char buffer[PAGE_SIZE];
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unsigned int len;
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unsigned int readpos;
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};
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/*
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* Trace iterator - used by printout routines who present trace
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* results to users and which routines might sleep, etc:
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*/
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struct trace_iterator {
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struct trace_array *tr;
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struct tracer *trace;
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void *private;
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struct ring_buffer_iter *buffer_iter[NR_CPUS];
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/* The below is zeroed out in pipe_read */
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struct trace_seq seq;
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struct trace_entry *ent;
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int cpu;
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u64 ts;
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unsigned long iter_flags;
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loff_t pos;
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long idx;
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cpumask_t started;
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};
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int tracing_is_enabled(void);
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void trace_wake_up(void);
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void tracing_reset(struct trace_array *tr, int cpu);
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int tracing_open_generic(struct inode *inode, struct file *filp);
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struct dentry *tracing_init_dentry(void);
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void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
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struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
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struct trace_array_cpu *data);
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void tracing_generic_entry_update(struct trace_entry *entry,
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unsigned long flags,
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int pc);
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void ftrace(struct trace_array *tr,
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struct trace_array_cpu *data,
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unsigned long ip,
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unsigned long parent_ip,
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unsigned long flags, int pc);
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void tracing_sched_switch_trace(struct trace_array *tr,
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struct trace_array_cpu *data,
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struct task_struct *prev,
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struct task_struct *next,
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unsigned long flags, int pc);
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void tracing_record_cmdline(struct task_struct *tsk);
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void tracing_sched_wakeup_trace(struct trace_array *tr,
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struct trace_array_cpu *data,
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struct task_struct *wakee,
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struct task_struct *cur,
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unsigned long flags, int pc);
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void trace_special(struct trace_array *tr,
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struct trace_array_cpu *data,
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unsigned long arg1,
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unsigned long arg2,
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unsigned long arg3, int pc);
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void trace_function(struct trace_array *tr,
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struct trace_array_cpu *data,
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unsigned long ip,
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unsigned long parent_ip,
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unsigned long flags, int pc);
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void trace_graph_return(struct ftrace_graph_ret *trace);
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void trace_graph_entry(struct ftrace_graph_ent *trace);
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void trace_bts(struct trace_array *tr,
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unsigned long from,
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unsigned long to);
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void tracing_start_cmdline_record(void);
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void tracing_stop_cmdline_record(void);
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void tracing_sched_switch_assign_trace(struct trace_array *tr);
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void tracing_stop_sched_switch_record(void);
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void tracing_start_sched_switch_record(void);
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int register_tracer(struct tracer *type);
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void unregister_tracer(struct tracer *type);
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extern unsigned long nsecs_to_usecs(unsigned long nsecs);
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extern unsigned long tracing_max_latency;
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extern unsigned long tracing_thresh;
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void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
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void update_max_tr_single(struct trace_array *tr,
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struct task_struct *tsk, int cpu);
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extern cycle_t ftrace_now(int cpu);
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#ifdef CONFIG_FUNCTION_TRACER
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void tracing_start_function_trace(void);
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void tracing_stop_function_trace(void);
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#else
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# define tracing_start_function_trace() do { } while (0)
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# define tracing_stop_function_trace() do { } while (0)
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#endif
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#ifdef CONFIG_CONTEXT_SWITCH_TRACER
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typedef void
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(*tracer_switch_func_t)(void *private,
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void *__rq,
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struct task_struct *prev,
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struct task_struct *next);
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struct tracer_switch_ops {
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tracer_switch_func_t func;
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void *private;
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struct tracer_switch_ops *next;
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};
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#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
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#ifdef CONFIG_DYNAMIC_FTRACE
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extern unsigned long ftrace_update_tot_cnt;
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#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
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extern int DYN_FTRACE_TEST_NAME(void);
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#endif
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#ifdef CONFIG_FTRACE_STARTUP_TEST
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extern int trace_selftest_startup_function(struct tracer *trace,
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struct trace_array *tr);
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extern int trace_selftest_startup_irqsoff(struct tracer *trace,
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struct trace_array *tr);
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extern int trace_selftest_startup_preemptoff(struct tracer *trace,
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struct trace_array *tr);
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extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
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struct trace_array *tr);
|
|
extern int trace_selftest_startup_wakeup(struct tracer *trace,
|
|
struct trace_array *tr);
|
|
extern int trace_selftest_startup_nop(struct tracer *trace,
|
|
struct trace_array *tr);
|
|
extern int trace_selftest_startup_sched_switch(struct tracer *trace,
|
|
struct trace_array *tr);
|
|
extern int trace_selftest_startup_sysprof(struct tracer *trace,
|
|
struct trace_array *tr);
|
|
extern int trace_selftest_startup_branch(struct tracer *trace,
|
|
struct trace_array *tr);
|
|
#endif /* CONFIG_FTRACE_STARTUP_TEST */
|
|
|
|
extern void *head_page(struct trace_array_cpu *data);
|
|
extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
|
|
extern void trace_seq_print_cont(struct trace_seq *s,
|
|
struct trace_iterator *iter);
|
|
|
|
extern int
|
|
seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
|
|
unsigned long sym_flags);
|
|
extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
|
|
size_t cnt);
|
|
extern long ns2usecs(cycle_t nsec);
|
|
extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
|
|
|
|
extern unsigned long trace_flags;
|
|
|
|
/* Standard output formatting function used for function return traces */
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
extern enum print_line_t print_graph_function(struct trace_iterator *iter);
|
|
#else
|
|
static inline enum print_line_t
|
|
print_graph_function(struct trace_iterator *iter)
|
|
{
|
|
return TRACE_TYPE_UNHANDLED;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* trace_iterator_flags is an enumeration that defines bit
|
|
* positions into trace_flags that controls the output.
|
|
*
|
|
* NOTE: These bits must match the trace_options array in
|
|
* trace.c.
|
|
*/
|
|
enum trace_iterator_flags {
|
|
TRACE_ITER_PRINT_PARENT = 0x01,
|
|
TRACE_ITER_SYM_OFFSET = 0x02,
|
|
TRACE_ITER_SYM_ADDR = 0x04,
|
|
TRACE_ITER_VERBOSE = 0x08,
|
|
TRACE_ITER_RAW = 0x10,
|
|
TRACE_ITER_HEX = 0x20,
|
|
TRACE_ITER_BIN = 0x40,
|
|
TRACE_ITER_BLOCK = 0x80,
|
|
TRACE_ITER_STACKTRACE = 0x100,
|
|
TRACE_ITER_SCHED_TREE = 0x200,
|
|
TRACE_ITER_PRINTK = 0x400,
|
|
TRACE_ITER_PREEMPTONLY = 0x800,
|
|
TRACE_ITER_BRANCH = 0x1000,
|
|
TRACE_ITER_ANNOTATE = 0x2000,
|
|
TRACE_ITER_USERSTACKTRACE = 0x4000,
|
|
TRACE_ITER_SYM_USEROBJ = 0x8000
|
|
};
|
|
|
|
/*
|
|
* TRACE_ITER_SYM_MASK masks the options in trace_flags that
|
|
* control the output of kernel symbols.
|
|
*/
|
|
#define TRACE_ITER_SYM_MASK \
|
|
(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
|
|
|
|
extern struct tracer nop_trace;
|
|
|
|
/**
|
|
* ftrace_preempt_disable - disable preemption scheduler safe
|
|
*
|
|
* When tracing can happen inside the scheduler, there exists
|
|
* cases that the tracing might happen before the need_resched
|
|
* flag is checked. If this happens and the tracer calls
|
|
* preempt_enable (after a disable), a schedule might take place
|
|
* causing an infinite recursion.
|
|
*
|
|
* To prevent this, we read the need_recshed flag before
|
|
* disabling preemption. When we want to enable preemption we
|
|
* check the flag, if it is set, then we call preempt_enable_no_resched.
|
|
* Otherwise, we call preempt_enable.
|
|
*
|
|
* The rational for doing the above is that if need resched is set
|
|
* and we have yet to reschedule, we are either in an atomic location
|
|
* (where we do not need to check for scheduling) or we are inside
|
|
* the scheduler and do not want to resched.
|
|
*/
|
|
static inline int ftrace_preempt_disable(void)
|
|
{
|
|
int resched;
|
|
|
|
resched = need_resched();
|
|
preempt_disable_notrace();
|
|
|
|
return resched;
|
|
}
|
|
|
|
/**
|
|
* ftrace_preempt_enable - enable preemption scheduler safe
|
|
* @resched: the return value from ftrace_preempt_disable
|
|
*
|
|
* This is a scheduler safe way to enable preemption and not miss
|
|
* any preemption checks. The disabled saved the state of preemption.
|
|
* If resched is set, then we were either inside an atomic or
|
|
* are inside the scheduler (we would have already scheduled
|
|
* otherwise). In this case, we do not want to call normal
|
|
* preempt_enable, but preempt_enable_no_resched instead.
|
|
*/
|
|
static inline void ftrace_preempt_enable(int resched)
|
|
{
|
|
if (resched)
|
|
preempt_enable_no_resched_notrace();
|
|
else
|
|
preempt_enable_notrace();
|
|
}
|
|
|
|
#ifdef CONFIG_BRANCH_TRACER
|
|
extern int enable_branch_tracing(struct trace_array *tr);
|
|
extern void disable_branch_tracing(void);
|
|
static inline int trace_branch_enable(struct trace_array *tr)
|
|
{
|
|
if (trace_flags & TRACE_ITER_BRANCH)
|
|
return enable_branch_tracing(tr);
|
|
return 0;
|
|
}
|
|
static inline void trace_branch_disable(void)
|
|
{
|
|
/* due to races, always disable */
|
|
disable_branch_tracing();
|
|
}
|
|
#else
|
|
static inline int trace_branch_enable(struct trace_array *tr)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline void trace_branch_disable(void)
|
|
{
|
|
}
|
|
#endif /* CONFIG_BRANCH_TRACER */
|
|
|
|
#endif /* _LINUX_KERNEL_TRACE_H */
|