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Commit 5beda5f6 authored by Ingo Molnar's avatar Ingo Molnar
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Merge branch 'tip/perf/core' of... 

Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
parents ba3dd36c 6752ab4a
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Showing with 74 additions and 197 deletions
Documentation/trace/ftrace-design.txt
View file @ 5beda5f6
......@@ -247,6 +247,13 @@ You need very few things to get the syscalls tracing in an arch.
- Support the TIF_SYSCALL_TRACEPOINT thread flags.
- Put the trace_sys_enter() and trace_sys_exit() tracepoints calls from ptrace
in the ptrace syscalls tracing path.
- If the system call table on this arch is more complicated than a simple array
of addresses of the system calls, implement an arch_syscall_addr to return
the address of a given system call.
- If the symbol names of the system calls do not match the function names on
this arch, define ARCH_HAS_SYSCALL_MATCH_SYM_NAME in asm/ftrace.h and
implement arch_syscall_match_sym_name with the appropriate logic to return
true if the function name corresponds with the symbol name.
- Tag this arch as HAVE_SYSCALL_TRACEPOINTS.
......
Documentation/trace/ftrace.txt
View file @ 5beda5f6
......@@ -80,11 +80,11 @@ of ftrace. Here is a list of some of the key files:
tracers listed here can be configured by
echoing their name into current_tracer.
tracing_enabled:
tracing_on:
This sets or displays whether the current_tracer
is activated and tracing or not. Echo 0 into this
file to disable the tracer or 1 to enable it.
This sets or displays whether writing to the trace
ring buffer is enabled. Echo 0 into this file to disable
the tracer or 1 to enable it.
trace:
......@@ -202,10 +202,6 @@ Here is the list of current tracers that may be configured.
to draw a graph of function calls similar to C code
source.
"sched_switch"
Traces the context switches and wakeups between tasks.
"irqsoff"
Traces the areas that disable interrupts and saves
......@@ -273,39 +269,6 @@ format, the function name that was traced "path_put" and the
parent function that called this function "path_walk". The
timestamp is the time at which the function was entered.
The sched_switch tracer also includes tracing of task wakeups
and context switches.
ksoftirqd/1-7 [01] 1453.070013: 7:115:R + 2916:115:S
ksoftirqd/1-7 [01] 1453.070013: 7:115:R + 10:115:S
ksoftirqd/1-7 [01] 1453.070013: 7:115:R ==> 10:115:R
events/1-10 [01] 1453.070013: 10:115:S ==> 2916:115:R
kondemand/1-2916 [01] 1453.070013: 2916:115:S ==> 7:115:R
ksoftirqd/1-7 [01] 1453.070013: 7:115:S ==> 0:140:R
Wake ups are represented by a "+" and the context switches are
shown as "==>". The format is:
Context switches:
Previous task Next Task
<pid>:<prio>:<state> ==> <pid>:<prio>:<state>
Wake ups:
Current task Task waking up
<pid>:<prio>:<state> + <pid>:<prio>:<state>
The prio is the internal kernel priority, which is the inverse
of the priority that is usually displayed by user-space tools.
Zero represents the highest priority (99). Prio 100 starts the
"nice" priorities with 100 being equal to nice -20 and 139 being
nice 19. The prio "140" is reserved for the idle task which is
the lowest priority thread (pid 0).
Latency trace format
--------------------
......@@ -491,79 +454,6 @@ x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6]
latencies, as described in "Latency
trace format".
sched_switch
------------
This tracer simply records schedule switches. Here is an example
of how to use it.
# echo sched_switch > current_tracer
# echo 1 > tracing_enabled
# sleep 1
# echo 0 > tracing_enabled
# cat trace
# tracer: sched_switch
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
bash-3997 [01] 240.132281: 3997:120:R + 4055:120:R
bash-3997 [01] 240.132284: 3997:120:R ==> 4055:120:R
sleep-4055 [01] 240.132371: 4055:120:S ==> 3997:120:R
bash-3997 [01] 240.132454: 3997:120:R + 4055:120:S
bash-3997 [01] 240.132457: 3997:120:R ==> 4055:120:R
sleep-4055 [01] 240.132460: 4055:120:D ==> 3997:120:R
bash-3997 [01] 240.132463: 3997:120:R + 4055:120:D
bash-3997 [01] 240.132465: 3997:120:R ==> 4055:120:R
<idle>-0 [00] 240.132589: 0:140:R + 4:115:S
<idle>-0 [00] 240.132591: 0:140:R ==> 4:115:R
ksoftirqd/0-4 [00] 240.132595: 4:115:S ==> 0:140:R
<idle>-0 [00] 240.132598: 0:140:R + 4:115:S
<idle>-0 [00] 240.132599: 0:140:R ==> 4:115:R
ksoftirqd/0-4 [00] 240.132603: 4:115:S ==> 0:140:R
sleep-4055 [01] 240.133058: 4055:120:S ==> 3997:120:R
[...]
As we have discussed previously about this format, the header
shows the name of the trace and points to the options. The
"FUNCTION" is a misnomer since here it represents the wake ups
and context switches.
The sched_switch file only lists the wake ups (represented with
'+') and context switches ('==>') with the previous task or
current task first followed by the next task or task waking up.
The format for both of these is PID:KERNEL-PRIO:TASK-STATE.
Remember that the KERNEL-PRIO is the inverse of the actual
priority with zero (0) being the highest priority and the nice
values starting at 100 (nice -20). Below is a quick chart to map
the kernel priority to user land priorities.
Kernel Space User Space
===============================================================
0(high) to 98(low) user RT priority 99(high) to 1(low)
with SCHED_RR or SCHED_FIFO
---------------------------------------------------------------
99 sched_priority is not used in scheduling
decisions(it must be specified as 0)
---------------------------------------------------------------
100(high) to 139(low) user nice -20(high) to 19(low)
---------------------------------------------------------------
140 idle task priority
---------------------------------------------------------------
The task states are:
R - running : wants to run, may not actually be running
S - sleep : process is waiting to be woken up (handles signals)
D - disk sleep (uninterruptible sleep) : process must be woken up
(ignores signals)
T - stopped : process suspended
t - traced : process is being traced (with something like gdb)
Z - zombie : process waiting to be cleaned up
X - unknown
ftrace_enabled
--------------
......@@ -607,10 +497,10 @@ an example:
# echo irqsoff > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# echo 1 > tracing_on
# ls -ltr
[...]
# echo 0 > tracing_enabled
# echo 0 > tracing_on
# cat trace
# tracer: irqsoff
#
......@@ -715,10 +605,10 @@ is much like the irqsoff tracer.
# echo preemptoff > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# echo 1 > tracing_on
# ls -ltr
[...]
# echo 0 > tracing_enabled
# echo 0 > tracing_on
# cat trace
# tracer: preemptoff
#
......@@ -863,10 +753,10 @@ tracers.
# echo preemptirqsoff > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# echo 1 > tracing_on
# ls -ltr
[...]
# echo 0 > tracing_enabled
# echo 0 > tracing_on
# cat trace
# tracer: preemptirqsoff
#
......@@ -1026,9 +916,9 @@ Instead of performing an 'ls', we will run 'sleep 1' under
# echo wakeup > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# echo 1 > tracing_on
# chrt -f 5 sleep 1
# echo 0 > tracing_enabled
# echo 0 > tracing_on
# cat trace
# tracer: wakeup
#
......@@ -1140,9 +1030,9 @@ ftrace_enabled is set; otherwise this tracer is a nop.
# sysctl kernel.ftrace_enabled=1
# echo function > current_tracer
# echo 1 > tracing_enabled
# echo 1 > tracing_on
# usleep 1
# echo 0 > tracing_enabled
# echo 0 > tracing_on
# cat trace
# tracer: function
#
......@@ -1180,7 +1070,7 @@ int trace_fd;
[...]
int main(int argc, char *argv[]) {
[...]
trace_fd = open(tracing_file("tracing_enabled"), O_WRONLY);
trace_fd = open(tracing_file("tracing_on"), O_WRONLY);
[...]
if (condition_hit()) {
write(trace_fd, "0", 1);
......@@ -1631,9 +1521,9 @@ If I am only interested in sys_nanosleep and hrtimer_interrupt:
# echo sys_nanosleep hrtimer_interrupt \
> set_ftrace_filter
# echo function > current_tracer
# echo 1 > tracing_enabled
# echo 1 > tracing_on
# usleep 1
# echo 0 > tracing_enabled
# echo 0 > tracing_on
# cat trace
# tracer: ftrace
#
......@@ -1879,9 +1769,9 @@ different. The trace is live.
# echo function > current_tracer
# cat trace_pipe > /tmp/trace.out &
[1] 4153
# echo 1 > tracing_enabled
# echo 1 > tracing_on
# usleep 1
# echo 0 > tracing_enabled
# echo 0 > tracing_on
# cat trace
# tracer: function
#
......
include/linux/syscalls.h
View file @ 5beda5f6
......@@ -132,11 +132,11 @@ extern struct trace_event_functions exit_syscall_print_funcs;
.class = &event_class_syscall_enter, \
.event.funcs = &enter_syscall_print_funcs, \
.data = (void *)&__syscall_meta_##sname,\
.flags = TRACE_EVENT_FL_CAP_ANY, \
}; \
static struct ftrace_event_call __used \
__attribute__((section("_ftrace_events"))) \
*__event_enter_##sname = &event_enter_##sname; \
__TRACE_EVENT_FLAGS(enter_##sname, TRACE_EVENT_FL_CAP_ANY)
*__event_enter_##sname = &event_enter_##sname;
#define SYSCALL_TRACE_EXIT_EVENT(sname) \
static struct syscall_metadata __syscall_meta_##sname; \
......@@ -146,11 +146,11 @@ extern struct trace_event_functions exit_syscall_print_funcs;
.class = &event_class_syscall_exit, \
.event.funcs = &exit_syscall_print_funcs, \
.data = (void *)&__syscall_meta_##sname,\
.flags = TRACE_EVENT_FL_CAP_ANY, \
}; \
static struct ftrace_event_call __used \
__attribute__((section("_ftrace_events"))) \
*__event_exit_##sname = &event_exit_##sname; \
__TRACE_EVENT_FLAGS(exit_##sname, TRACE_EVENT_FL_CAP_ANY)
*__event_exit_##sname = &event_exit_##sname;
#define SYSCALL_METADATA(sname, nb) \
SYSCALL_TRACE_ENTER_EVENT(sname); \
......@@ -158,6 +158,7 @@ extern struct trace_event_functions exit_syscall_print_funcs;
static struct syscall_metadata __used \
__syscall_meta_##sname = { \
.name = "sys"#sname, \
.syscall_nr = -1, /* Filled in at boot */ \
.nb_args = nb, \
.types = types_##sname, \
.args = args_##sname, \
......@@ -175,6 +176,7 @@ extern struct trace_event_functions exit_syscall_print_funcs;
static struct syscall_metadata __used \
__syscall_meta__##sname = { \
.name = "sys_"#sname, \
.syscall_nr = -1, /* Filled in at boot */ \
.nb_args = 0, \
.enter_event = &event_enter__##sname, \
.exit_event = &event_exit__##sname, \
......
kernel/trace/ring_buffer.c
View file @ 5beda5f6
......@@ -2163,10 +2163,14 @@ rb_reserve_next_event(struct ring_buffer *buffer,
delta = diff;
if (unlikely(test_time_stamp(delta))) {
WARN_ONCE(delta > (1ULL << 59),
KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n",
KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n%s",
(unsigned long long)delta,
(unsigned long long)ts,
(unsigned long long)cpu_buffer->write_stamp);
(unsigned long long)cpu_buffer->write_stamp,
sched_clock_stable ? "" :
"If you just came from a suspend/resume,\n"
"please switch to the trace global clock:\n"
" echo global > /sys/kernel/debug/tracing/trace_clock\n");
add_timestamp = 1;
}
}
......
kernel/trace/trace.c
View file @ 5beda5f6
......@@ -2710,6 +2710,10 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf,
mutex_lock(&trace_types_lock);
if (tracer_enabled ^ val) {
/* Only need to warn if this is used to change the state */
WARN_ONCE(1, "tracing_enabled is deprecated. Use tracing_on");
if (val) {
tracer_enabled = 1;
if (current_trace->start)
......
kernel/trace/trace_sched_switch.c
View file @ 5beda5f6
......@@ -247,51 +247,3 @@ void tracing_sched_switch_assign_trace(struct trace_array *tr)
ctx_trace = tr;
}
static void stop_sched_trace(struct trace_array *tr)
{
tracing_stop_sched_switch_record();
}
static int sched_switch_trace_init(struct trace_array *tr)
{
ctx_trace = tr;
tracing_reset_online_cpus(tr);
tracing_start_sched_switch_record();
return 0;
}
static void sched_switch_trace_reset(struct trace_array *tr)
{
if (sched_ref)
stop_sched_trace(tr);
}
static void sched_switch_trace_start(struct trace_array *tr)
{
sched_stopped = 0;
}
static void sched_switch_trace_stop(struct trace_array *tr)
{
sched_stopped = 1;
}
static struct tracer sched_switch_trace __read_mostly =
{
.name = "sched_switch",
.init = sched_switch_trace_init,
.reset = sched_switch_trace_reset,
.start = sched_switch_trace_start,
.stop = sched_switch_trace_stop,
.wait_pipe = poll_wait_pipe,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_sched_switch,
#endif
};
__init static int init_sched_switch_trace(void)
{
return register_tracer(&sched_switch_trace);
}
device_initcall(init_sched_switch_trace);
kernel/trace/trace_syscalls.c
View file @ 5beda5f6
......@@ -60,6 +60,19 @@ extern struct syscall_metadata *__stop_syscalls_metadata[];
static struct syscall_metadata **syscalls_metadata;
#ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME
static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
{
/*
* Only compare after the "sys" prefix. Archs that use
* syscall wrappers may have syscalls symbols aliases prefixed
* with "SyS" instead of "sys", leading to an unwanted
* mismatch.
*/
return !strcmp(sym + 3, name + 3);
}
#endif
static __init struct syscall_metadata *
find_syscall_meta(unsigned long syscall)
{
......@@ -72,14 +85,11 @@ find_syscall_meta(unsigned long syscall)
stop = __stop_syscalls_metadata;
kallsyms_lookup(syscall, NULL, NULL, NULL, str);
if (arch_syscall_match_sym_name(str, "sys_ni_syscall"))
return NULL;
for ( ; start < stop; start++) {
/*
* Only compare after the "sys" prefix. Archs that use
* syscall wrappers may have syscalls symbols aliases prefixed
* with "SyS" instead of "sys", leading to an unwanted
* mismatch.
*/
if ((*start)->name && !strcmp((*start)->name + 3, str + 3))
if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name))
return *start;
}
return NULL;
......@@ -359,7 +369,7 @@ int reg_event_syscall_enter(struct ftrace_event_call *call)
int num;
num = ((struct syscall_metadata *)call->data)->syscall_nr;
if (num < 0 || num >= NR_syscalls)
if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
return -ENOSYS;
mutex_lock(&syscall_trace_lock);
if (!sys_refcount_enter)
......@@ -377,7 +387,7 @@ void unreg_event_syscall_enter(struct ftrace_event_call *call)
int num;
num = ((struct syscall_metadata *)call->data)->syscall_nr;
if (num < 0 || num >= NR_syscalls)
if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
return;
mutex_lock(&syscall_trace_lock);
sys_refcount_enter--;
......@@ -393,7 +403,7 @@ int reg_event_syscall_exit(struct ftrace_event_call *call)
int num;
num = ((struct syscall_metadata *)call->data)->syscall_nr;
if (num < 0 || num >= NR_syscalls)
if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
return -ENOSYS;
mutex_lock(&syscall_trace_lock);
if (!sys_refcount_exit)
......@@ -411,7 +421,7 @@ void unreg_event_syscall_exit(struct ftrace_event_call *call)
int num;
num = ((struct syscall_metadata *)call->data)->syscall_nr;
if (num < 0 || num >= NR_syscalls)
if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
return;
mutex_lock(&syscall_trace_lock);
sys_refcount_exit--;
......@@ -424,6 +434,14 @@ void unreg_event_syscall_exit(struct ftrace_event_call *call)
int init_syscall_trace(struct ftrace_event_call *call)
{
int id;
int num;
num = ((struct syscall_metadata *)call->data)->syscall_nr;
if (num < 0 || num >= NR_syscalls) {
pr_debug("syscall %s metadata not mapped, disabling ftrace event\n",
((struct syscall_metadata *)call->data)->name);
return -ENOSYS;
}
if (set_syscall_print_fmt(call) < 0)
return -ENOMEM;
......@@ -438,7 +456,7 @@ int init_syscall_trace(struct ftrace_event_call *call)
return id;
}
unsigned long __init arch_syscall_addr(int nr)
unsigned long __init __weak arch_syscall_addr(int nr)
{
return (unsigned long)sys_call_table[nr];
}
......
scripts/kconfig/streamline_config.pl
View file @ 5beda5f6
#!/usr/bin/perl -w
#
# Copywrite 2005-2009 - Steven Rostedt
# Copyright 2005-2009 - Steven Rostedt
# Licensed under the terms of the GNU GPL License version 2
#
# It's simple enough to figure out how this works.
......
tools/testing/ktest/ktest.pl
View file @ 5beda5f6
#!/usr/bin/perl -w
#
# Copywrite 2010 - Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
# Copyright 2010 - Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
# Licensed under the terms of the GNU GPL License version 2
#
......
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