Commit 58ca2415 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing updates from Steven Rostedt:

 - simplify the Kconfig use of FTRACE and TRACE_IRQFLAGS_SUPPORT

 - bootconfig can now start histograms

 - bootconfig supports group/all enabling

 - histograms now can put values in linear size buckets

 - execnames can be passed to synthetic events

 - introduce "event probes" that attach to other events and can retrieve
   data from pointers of fields, or record fields as different types (a
   pointer to a string as a string instead of just a hex number)

 - various fixes and clean ups

* tag 'trace-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (35 commits)
  tracing/doc: Fix table format in histogram code
  selftests/ftrace: Add selftest for testing duplicate eprobes and kprobes
  selftests/ftrace: Add selftest for testing eprobe events on synthetic events
  selftests/ftrace: Add test case to test adding and removing of event probe
  selftests/ftrace: Fix requirement check of README file
  selftests/ftrace: Add clear_dynamic_events() to test cases
  tracing: Add a probe that attaches to trace events
  tracing/probes: Reject events which have the same name of existing one
  tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs
  tracing/probe: Change traceprobe_set_print_fmt() to take a type
  tracing/probes: Use struct_size() instead of defining custom macros
  tracing/probes: Allow for dot delimiter as well as slash for system names
  tracing/probe: Have traceprobe_parse_probe_arg() take a const arg
  tracing: Have dynamic events have a ref counter
  tracing: Add DYNAMIC flag for dynamic events
  tracing: Replace deprecated CPU-hotplug functions.
  MAINTAINERS: Add an entry for os noise/latency
  tracepoint: Fix kerneldoc comments
  bootconfig/tracing/ktest: Update ktest example for boot-time tracing
  tools/bootconfig: Use per-group/all enable option in ftrace2bconf script
  ...
parents e07af262 4420f5b1

Documentation/trace/boottime-trace.rst

+80 −5
Original line number Diff line number Diff line
@@ -125,6 +125,71 @@ Note that kprobe and synthetic event definitions can be written under 
instance node, but those are also visible from other instances. So please

take care for event name conflict.



Ftrace Histogram Options

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



Since it is too long to write a histogram action as a string for per-event

action option, there are tree-style options under per-event 'hist' subkey

for the histogram actions. For the detail of the each parameter,

please read the event histogram document [3]_.



.. [3] See :ref:`Documentation/trace/histogram.rst <histogram>`



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]keys = KEY1[, KEY2[...]]

  Set histogram key parameters. (Mandatory)

  The 'N' is a digit string for the multiple histogram. You can omit it

  if there is one histogram on the event.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]values = VAL1[, VAL2[...]]

  Set histogram value parameters.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]sort = SORT1[, SORT2[...]]

  Set histogram sort parameter options.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]size = NR_ENTRIES

  Set histogram size (number of entries).



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]name = NAME

  Set histogram name.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]var.VARIABLE = EXPR

  Define a new VARIABLE by EXPR expression.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]<pause|continue|clear>

  Set histogram control parameter. You can set one of them.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]onmatch.[M.]event = GROUP.EVENT

  Set histogram 'onmatch' handler matching event parameter.

  The 'M' is a digit string for the multiple 'onmatch' handler. You can omit it

  if there is one 'onmatch' handler on this histogram.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]onmatch.[M.]trace = EVENT[, ARG1[...]]

  Set histogram 'trace' action for 'onmatch'.

  EVENT must be a synthetic event name, and ARG1... are parameters

  for that event. Mandatory if 'onmatch.event' option is set.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]onmax.[M.]var = VAR

  Set histogram 'onmax' handler variable parameter.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]onchange.[M.]var = VAR

  Set histogram 'onchange' handler variable parameter.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]<onmax|onchange>.[M.]save = ARG1[, ARG2[...]]

  Set histogram 'save' action parameters for 'onmax' or 'onchange' handler.

  This option or below 'snapshot' option is mandatory if 'onmax.var' or

  'onchange.var' option is set.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.[N.]<onmax|onchange>.[M.]snapshot

  Set histogram 'snapshot' action for 'onmax' or 'onchange' handler.

  This option or above 'save' option is mandatory if 'onmax.var' or

  'onchange.var' option is set.



ftrace.[instance.INSTANCE.]event.GROUP.EVENT.hist.filter = FILTER_EXPR

  Set histogram filter expression. You don't need 'if' in the FILTER_EXPR.



Note that this 'hist' option can conflict with the per-event 'actions'

option if the 'actions' option has a histogram action.





When to Start

=============
@@ -159,13 +224,23 @@ below:: 
        }

        synthetic.initcall_latency {

                fields = "unsigned long func", "u64 lat"

                actions = "hist:keys=func.sym,lat:vals=lat:sort=lat"

                hist {

                        keys = func.sym, lat

                        values = lat

                        sort = lat

                }

        }

        initcall.initcall_start.hist {

                keys = func

                var.ts0 = common_timestamp.usecs

        }

        initcall.initcall_start {

                actions = "hist:keys=func:ts0=common_timestamp.usecs"

        initcall.initcall_finish.hist {

                keys = func

                var.lat = common_timestamp.usecs - $ts0

                onmatch {

                        event = initcall.initcall_start

                        trace = initcall_latency, func, $lat

                }

        initcall.initcall_finish {

                actions = "hist:keys=func:lat=common_timestamp.usecs-$ts0:onmatch(initcall.initcall_start).initcall_latency(func,$lat)"

        }

  }

Documentation/trace/histogram.rst

+95 −15
Original line number Diff line number Diff line
@@ -70,15 +70,16 @@ Documentation written by Tom Zanussi 
  modified by appending any of the following modifiers to the field

  name:



	=========== ==========================================

	=============  =================================================

        .hex           display a number as a hex value

	.sym           display an address as a symbol

	.sym-offset    display an address as a symbol and offset

	.syscall       display a syscall id as a system call name

	.execname      display a common_pid as a program name

	.log2          display log2 value rather than raw number

	.buckets=size  display grouping of values rather than raw number

	.usecs         display a common_timestamp in microseconds

	=========== ==========================================

	=============  =================================================



  Note that in general the semantics of a given field aren't

  interpreted when applying a modifier to it, but there are some
@@ -228,7 +229,7 @@ Extended error information 
  that lists the total number of bytes requested for each function in

  the kernel that made one or more calls to kmalloc::



    # echo 'hist:key=call_site:val=bytes_req' > \

    # echo 'hist:key=call_site:val=bytes_req.buckets=32' > \

            /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger



  This tells the tracing system to create a 'hist' trigger using the
@@ -1823,20 +1824,99 @@ and variables defined on other events (see Section 2.2.3 below on 
how that is done using hist trigger 'onmatch' action). Once that is

done, the 'wakeup_latency' synthetic event instance is created.



A histogram can now be defined for the new synthetic event::



  # echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \

        /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger



The new event is created under the tracing/events/synthetic/ directory

and looks and behaves just like any other event::



  # ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency

        enable  filter  format  hist  id  trigger



A histogram can now be defined for the new synthetic event::



  # echo 'hist:keys=pid,prio,lat.log2:sort=lat' >> \

        /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger



The above shows the latency "lat" in a power of 2 grouping.



Like any other event, once a histogram is enabled for the event, the

output can be displayed by reading the event's 'hist' file.



  # cat /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/hist



  # event histogram

  #

  # trigger info: hist:keys=pid,prio,lat.log2:vals=hitcount:sort=lat.log2:size=2048 [active]

  #



  { pid:       2035, prio:          9, lat: ~ 2^2  } hitcount:         43

  { pid:       2034, prio:          9, lat: ~ 2^2  } hitcount:         60

  { pid:       2029, prio:          9, lat: ~ 2^2  } hitcount:        965

  { pid:       2034, prio:        120, lat: ~ 2^2  } hitcount:          9

  { pid:       2033, prio:        120, lat: ~ 2^2  } hitcount:          5

  { pid:       2030, prio:          9, lat: ~ 2^2  } hitcount:        335

  { pid:       2030, prio:        120, lat: ~ 2^2  } hitcount:         10

  { pid:       2032, prio:        120, lat: ~ 2^2  } hitcount:          1

  { pid:       2035, prio:        120, lat: ~ 2^2  } hitcount:          2

  { pid:       2031, prio:          9, lat: ~ 2^2  } hitcount:        176

  { pid:       2028, prio:        120, lat: ~ 2^2  } hitcount:         15

  { pid:       2033, prio:          9, lat: ~ 2^2  } hitcount:         91

  { pid:       2032, prio:          9, lat: ~ 2^2  } hitcount:        125

  { pid:       2029, prio:        120, lat: ~ 2^2  } hitcount:          4

  { pid:       2031, prio:        120, lat: ~ 2^2  } hitcount:          3

  { pid:       2029, prio:        120, lat: ~ 2^3  } hitcount:          2

  { pid:       2035, prio:          9, lat: ~ 2^3  } hitcount:         41

  { pid:       2030, prio:        120, lat: ~ 2^3  } hitcount:          1

  { pid:       2032, prio:          9, lat: ~ 2^3  } hitcount:         32

  { pid:       2031, prio:          9, lat: ~ 2^3  } hitcount:         44

  { pid:       2034, prio:          9, lat: ~ 2^3  } hitcount:         40

  { pid:       2030, prio:          9, lat: ~ 2^3  } hitcount:         29

  { pid:       2033, prio:          9, lat: ~ 2^3  } hitcount:         31

  { pid:       2029, prio:          9, lat: ~ 2^3  } hitcount:         31

  { pid:       2028, prio:        120, lat: ~ 2^3  } hitcount:         18

  { pid:       2031, prio:        120, lat: ~ 2^3  } hitcount:          2

  { pid:       2028, prio:        120, lat: ~ 2^4  } hitcount:          1

  { pid:       2029, prio:          9, lat: ~ 2^4  } hitcount:          4

  { pid:       2031, prio:        120, lat: ~ 2^7  } hitcount:          1

  { pid:       2032, prio:        120, lat: ~ 2^7  } hitcount:          1



  Totals:

      Hits: 2122

      Entries: 30

      Dropped: 0





The latency values can also be grouped linearly by a given size with

the ".buckets" modifier and specify a size (in this case groups of 10).



  # echo 'hist:keys=pid,prio,lat.buckets=10:sort=lat' >> \

        /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger



  # event histogram

  #

  # trigger info: hist:keys=pid,prio,lat.buckets=10:vals=hitcount:sort=lat.buckets=10:size=2048 [active]

  #



  { pid:       2067, prio:          9, lat: ~ 0-9 } hitcount:        220

  { pid:       2068, prio:          9, lat: ~ 0-9 } hitcount:        157

  { pid:       2070, prio:          9, lat: ~ 0-9 } hitcount:        100

  { pid:       2067, prio:        120, lat: ~ 0-9 } hitcount:          6

  { pid:       2065, prio:        120, lat: ~ 0-9 } hitcount:          2

  { pid:       2066, prio:        120, lat: ~ 0-9 } hitcount:          2

  { pid:       2069, prio:          9, lat: ~ 0-9 } hitcount:        122

  { pid:       2069, prio:        120, lat: ~ 0-9 } hitcount:          8

  { pid:       2070, prio:        120, lat: ~ 0-9 } hitcount:          1

  { pid:       2068, prio:        120, lat: ~ 0-9 } hitcount:          7

  { pid:       2066, prio:          9, lat: ~ 0-9 } hitcount:        365

  { pid:       2064, prio:        120, lat: ~ 0-9 } hitcount:         35

  { pid:       2065, prio:          9, lat: ~ 0-9 } hitcount:        998

  { pid:       2071, prio:          9, lat: ~ 0-9 } hitcount:         85

  { pid:       2065, prio:          9, lat: ~ 10-19 } hitcount:          2

  { pid:       2064, prio:        120, lat: ~ 10-19 } hitcount:          2



  Totals:

      Hits: 2112

      Entries: 16

      Dropped: 0



2.2.3 Hist trigger 'handlers' and 'actions'

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

MAINTAINERS

+14 −0
Original line number Diff line number Diff line
@@ -18973,6 +18973,20 @@ F: arch/x86/mm/testmmiotrace.c 
F:	include/linux/mmiotrace.h

F:	kernel/trace/trace_mmiotrace.c









TRACING OS NOISE / LATENCY TRACERS









M:	Steven Rostedt <rostedt@goodmis.org>









M:	Daniel Bristot de Oliveira <bristot@kernel.org>









S:	Maintained









F:	kernel/trace/trace_osnoise.c









F:	include/trace/events/osnoise.h









F:	kernel/trace/trace_hwlat.c









F:	kernel/trace/trace_irqsoff.c









F:	kernel/trace/trace_sched_wakeup.c









F:	Documentation/trace/osnoise-tracer.rst









F:	Documentation/trace/timerlat-tracer.rst









F:	Documentation/trace/hwlat_detector.rst









F:	arch/*/kernel/trace.c

















TRADITIONAL CHINESE DOCUMENTATION









M:	Hu Haowen <src.res@email.cn>









L:	linux-doc-tw-discuss@lists.sourceforge.net

























arch/Kconfig



+3
−0






























Original line number
Diff line number
Diff line







@@ -197,6 +197,9 @@ config HAVE_FUNCTION_ERROR_INJECTION







config HAVE_NMI









	bool



















config TRACE_IRQFLAGS_SUPPORT









	bool



















#









# An arch should select this if it provides all these things:









#
































arch/arc/Kconfig



+1
−3






























Original line number
Diff line number
Diff line







@@ -49,9 +49,7 @@ config ARC







	select PERF_USE_VMALLOC if ARC_CACHE_VIPT_ALIASING









	select HAVE_ARCH_JUMP_LABEL if ISA_ARCV2 && !CPU_ENDIAN_BE32









	select SET_FS



















config TRACE_IRQFLAGS_SUPPORT









	def_bool y









	select TRACE_IRQFLAGS_SUPPORT



















config LOCKDEP_SUPPORT









	def_bool y