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Commit a926021c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'perf-core-for-linus' of... 

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (184 commits)
  perf probe: Clean up probe_point_lazy_walker() return value
  tracing: Fix irqoff selftest expanding max buffer
  tracing: Align 4 byte ints together in struct tracer
  tracing: Export trace_set_clr_event()
  tracing: Explain about unstable clock on resume with ring buffer warning
  ftrace/graph: Trace function entry before updating index
  ftrace: Add .ref.text as one of the safe areas to trace
  tracing: Adjust conditional expression latency formatting.
  tracing: Fix event alignment: skb:kfree_skb
  tracing: Fix event alignment: mce:mce_record
  tracing: Fix event alignment: kvm:kvm_hv_hypercall
  tracing: Fix event alignment: module:module_request
  tracing: Fix event alignment: ftrace:context_switch and ftrace:wakeup
  tracing: Remove lock_depth from event entry
  perf header: Stop using 'self'
  perf session: Use evlist/evsel for managing perf.data attributes
  perf top: Don't let events to eat up whole header line
  perf top: Fix events overflow in top command
  ring-buffer: Remove unused #include <linux/trace_irq.h>
  tracing: Add an 'overwrite' trace_option.
  ...
parents 0586bed3 5e814dd5

Documentation/trace/ftrace-design.txt

+7 −0
Original line number Diff line number Diff line
@@ -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

+23 −128
Original line number Diff line number Diff line
@@ -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

--------------------
@@ -491,78 +454,10 @@ 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



  overwrite - This controls what happens when the trace buffer is

              full. If "1" (default), the oldest events are

              discarded and overwritten. If "0", then the newest

              events are discarded.



ftrace_enabled

--------------
@@ -607,10 +502,10 @@ 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 +610,10 @@ 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 +758,10 @@ 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 +921,9 @@ 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 +1035,9 @@ 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 +1075,7 @@ 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 +1526,9 @@ 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 +1774,9 @@ 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

#

Documentation/trace/kprobetrace.txt

+15 −1
Original line number Diff line number Diff line
@@ -42,11 +42,25 @@ Synopsis of kprobe_events 
  +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)

  NAME=FETCHARG : Set NAME as the argument name of FETCHARG.

  FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types

		  (u8/u16/u32/u64/s8/s16/s32/s64) and string are supported.

		  (u8/u16/u32/u64/s8/s16/s32/s64), "string" and bitfield

		  are supported.



  (*) only for return probe.

  (**) this is useful for fetching a field of data structures.



Types

-----

Several types are supported for fetch-args. Kprobe tracer will access memory

by given type. Prefix 's' and 'u' means those types are signed and unsigned

respectively. Traced arguments are shown in decimal (signed) or hex (unsigned).

String type is a special type, which fetches a "null-terminated" string from

kernel space. This means it will fail and store NULL if the string container

has been paged out.

Bitfield is another special type, which takes 3 parameters, bit-width, bit-

offset, and container-size (usually 32). The syntax is;



 b<bit-width>@<bit-offset>/<container-size>





Per-Probe Event Filtering

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

arch/x86/ia32/ia32entry.S

+2 −0
Original line number Diff line number Diff line
@@ -25,6 +25,8 @@ 
#define sysretl_audit ia32_ret_from_sys_call

#endif



	.section .entry.text, "ax"



#define IA32_NR_syscalls ((ia32_syscall_end - ia32_sys_call_table)/8)



	.macro IA32_ARG_FIXUP noebp=0

arch/x86/include/asm/cpufeature.h

+2 −0
Original line number Diff line number Diff line
@@ -160,6 +160,7 @@ 
#define X86_FEATURE_NODEID_MSR	(6*32+19) /* NodeId MSR */

#define X86_FEATURE_TBM		(6*32+21) /* trailing bit manipulations */

#define X86_FEATURE_TOPOEXT	(6*32+22) /* topology extensions CPUID leafs */

#define X86_FEATURE_PERFCTR_CORE (6*32+23) /* core performance counter extensions */



/*

 * Auxiliary flags: Linux defined - For features scattered in various
@@ -279,6 +280,7 @@ extern const char * const x86_power_flags[32]; 
#define cpu_has_xsave		boot_cpu_has(X86_FEATURE_XSAVE)

#define cpu_has_hypervisor	boot_cpu_has(X86_FEATURE_HYPERVISOR)

#define cpu_has_pclmulqdq	boot_cpu_has(X86_FEATURE_PCLMULQDQ)

#define cpu_has_perfctr_core	boot_cpu_has(X86_FEATURE_PERFCTR_CORE)



#if defined(CONFIG_X86_INVLPG) || defined(CONFIG_X86_64)

# define cpu_has_invlpg		1