Commit c7cc7730 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branches 'tracing/blktrace', 'tracing/ftrace',... 

Merge branches 'tracing/blktrace', 'tracing/ftrace', 'tracing/function-graph-tracer' and 'tracing/power-tracer' into tracing/core
parents 0bfc2455 d144d5ee 437f24fb f3f47a67

Documentation/ftrace.txt

+79 −0
Original line number Diff line number Diff line
@@ -127,6 +127,8 @@ of ftrace. Here is a list of some of the key files: 
		be traced. If a function exists in both set_ftrace_filter

		and set_ftrace_notrace,	the function will _not_ be traced.



  set_ftrace_pid: Have the function tracer only trace a single thread.



  available_filter_functions: This lists the functions that ftrace

		has processed and can trace. These are the function

		names that you can pass to "set_ftrace_filter" or
@@ -1073,6 +1075,83 @@ For simple one time traces, the above is sufficent. For anything else, 
a search through /proc/mounts may be needed to find where the debugfs

file-system is mounted.





Single thread tracing

---------------------



By writing into /debug/tracing/set_ftrace_pid you can trace a

single thread. For example:



# cat /debug/tracing/set_ftrace_pid

no pid

# echo 3111 > /debug/tracing/set_ftrace_pid

# cat /debug/tracing/set_ftrace_pid

3111

# echo function > /debug/tracing/current_tracer

# cat /debug/tracing/trace | head

 # tracer: function

 #

 #           TASK-PID    CPU#    TIMESTAMP  FUNCTION

 #              | |       |          |         |

     yum-updatesd-3111  [003]  1637.254676: finish_task_switch <-thread_return

     yum-updatesd-3111  [003]  1637.254681: hrtimer_cancel <-schedule_hrtimeout_range

     yum-updatesd-3111  [003]  1637.254682: hrtimer_try_to_cancel <-hrtimer_cancel

     yum-updatesd-3111  [003]  1637.254683: lock_hrtimer_base <-hrtimer_try_to_cancel

     yum-updatesd-3111  [003]  1637.254685: fget_light <-do_sys_poll

     yum-updatesd-3111  [003]  1637.254686: pipe_poll <-do_sys_poll

# echo -1 > /debug/tracing/set_ftrace_pid

# cat /debug/tracing/trace |head

 # tracer: function

 #

 #           TASK-PID    CPU#    TIMESTAMP  FUNCTION

 #              | |       |          |         |

 ##### CPU 3 buffer started ####

     yum-updatesd-3111  [003]  1701.957688: free_poll_entry <-poll_freewait

     yum-updatesd-3111  [003]  1701.957689: remove_wait_queue <-free_poll_entry

     yum-updatesd-3111  [003]  1701.957691: fput <-free_poll_entry

     yum-updatesd-3111  [003]  1701.957692: audit_syscall_exit <-sysret_audit

     yum-updatesd-3111  [003]  1701.957693: path_put <-audit_syscall_exit



If you want to trace a function when executing, you could use

something like this simple program:



#include <stdio.h>

#include <stdlib.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <unistd.h>



int main (int argc, char **argv)

{

        if (argc < 1)

                exit(-1);



        if (fork() > 0) {

                int fd, ffd;

                char line[64];

                int s;



                ffd = open("/debug/tracing/current_tracer", O_WRONLY);

                if (ffd < 0)

                        exit(-1);

                write(ffd, "nop", 3);



                fd = open("/debug/tracing/set_ftrace_pid", O_WRONLY);

                s = sprintf(line, "%d\n", getpid());

                write(fd, line, s);



                write(ffd, "function", 8);



                close(fd);

                close(ffd);



                execvp(argv[1], argv+1);

        }



        return 0;

}



dynamic ftrace

--------------

arch/x86/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ config X86 
	select HAVE_FTRACE_MCOUNT_RECORD

	select HAVE_DYNAMIC_FTRACE

	select HAVE_FUNCTION_TRACER

	select HAVE_FUNCTION_RET_TRACER if X86_32

	select HAVE_FUNCTION_GRAPH_TRACER if X86_32

	select HAVE_FUNCTION_TRACE_MCOUNT_TEST

	select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)

	select HAVE_ARCH_KGDB if !X86_VOYAGER

arch/x86/include/asm/ftrace.h

+2 −2
Original line number Diff line number Diff line
@@ -28,7 +28,7 @@ struct dyn_arch_ftrace { 
#endif /* __ASSEMBLY__ */

#endif /* CONFIG_FUNCTION_TRACER */



#ifdef CONFIG_FUNCTION_RET_TRACER

#ifdef CONFIG_FUNCTION_GRAPH_TRACER



#ifndef __ASSEMBLY__
@@ -51,6 +51,6 @@ struct ftrace_ret_stack { 
extern void return_to_handler(void);



#endif /* __ASSEMBLY__ */

#endif /* CONFIG_FUNCTION_RET_TRACER */

#endif /* CONFIG_FUNCTION_GRAPH_TRACER */



#endif /* _ASM_X86_FTRACE_H */

arch/x86/kernel/Makefile

+2 −2
Original line number Diff line number Diff line
@@ -14,7 +14,7 @@ CFLAGS_REMOVE_paravirt-spinlocks.o = -pg 
CFLAGS_REMOVE_ftrace.o = -pg

endif



ifdef CONFIG_FUNCTION_RET_TRACER

ifdef CONFIG_FUNCTION_GRAPH_TRACER

# Don't trace __switch_to() but let it for function tracer

CFLAGS_REMOVE_process_32.o = -pg

endif
@@ -70,7 +70,7 @@ obj-$(CONFIG_X86_LOCAL_APIC) += apic.o nmi.o 
obj-$(CONFIG_X86_IO_APIC)	+= io_apic.o

obj-$(CONFIG_X86_REBOOTFIXUPS)	+= reboot_fixups_32.o

obj-$(CONFIG_DYNAMIC_FTRACE)	+= ftrace.o

obj-$(CONFIG_FUNCTION_RET_TRACER)	+= ftrace.o

obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o

obj-$(CONFIG_KEXEC)		+= machine_kexec_$(BITS).o

obj-$(CONFIG_KEXEC)		+= relocate_kernel_$(BITS).o crash.o

obj-$(CONFIG_CRASH_DUMP)	+= crash_dump_$(BITS).o

arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c

+4 −0
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/cpufreq.h>

#include <linux/compiler.h>

#include <linux/dmi.h>

#include <linux/ftrace.h>



#include <linux/acpi.h>

#include <acpi/processor.h>
@@ -391,6 +392,7 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, 
	unsigned int next_perf_state = 0; /* Index into perf table */

	unsigned int i;

	int result = 0;

	struct power_trace it;



	dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
@@ -427,6 +429,8 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, 
		}

	}



	trace_power_mark(&it, POWER_PSTATE, next_perf_state);



	switch (data->cpu_feature) {

	case SYSTEM_INTEL_MSR_CAPABLE:

		cmd.type = SYSTEM_INTEL_MSR_CAPABLE;