Commit Graph

16 Commits

Author SHA1 Message Date
Adrian Hunter 3749e0bbde perf thread-stack: Add thread_stack__br_sample_late()
Add a thread stack function to create a branch stack for hardware events
where the sample records get created some time after the event occurred.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200429150751.12570-7-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-05-05 16:35:29 -03:00
Adrian Hunter 86d67180b9 perf thread-stack: Add branch stack support
Intel PT already has support for creating branch stacks for each context
(per-cpu or per-thread). In the more common per-cpu case, the branch stack
is not separated for different threads, instead being cleared in between
each sample.

That approach will not work very well for adding branch stacks to
regular events. The branch stacks really need to be accumulated
separately for each thread.

As a start to accomplishing that, this patch adds support for putting
branch stack support into the thread-stack. The advantages are:

1. the branches are accumulated separately for each thread
2. the branch stack is cleared only in between continuous traces

This helps pave the way for adding branch stacks to regular events, not
just synthesized events as at present.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200429150751.12570-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-05-05 16:35:29 -03:00
Adrian Hunter 4fef41bfb1 perf thread-stack: Add thread_stack__sample_late()
Add a thread stack function to create a call chain for hardware events
where the sample records get created some time after the event occurred.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200401101613.6201-10-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-04-16 12:19:15 -03:00
Ingo Molnar 3ce5aceb5d perf/core improvements and fixes:
perf record:
 
   Alexey Budankov:
 
   - Allow mixing --user-regs with --call-graph=dwarf, making sure that
     the minimal set of registers for DWARF unwinding is present in the
     set of user registers requested to be present in each sample, while
     warning the user that this may make callchains unreliable if more
     that the minimal set of registers is needed to unwind.
 
   yuzhoujian:
 
   - Add support to collect callchains from kernel or user space only,
     IOW allow setting the perf_event_attr.exclude_callchain_{kernel,user}
     bits from the command line.
 
 perf trace:
 
   Arnaldo Carvalho de Melo:
 
   - Remove x86_64 specific syscall numbers from the augmented_raw_syscalls
     BPF in-kernel collector of augmented raw_syscalls:sys_{enter,exit}
     payloads, use instead the syscall numbers obtainer either by the
     arch specific syscalltbl generators or from audit-libs.
 
   - Allow 'perf trace' to ask for the number of bytes to collect for
     string arguments, for now ask for PATH_MAX, i.e. the whole
     pathnames, which ends up being just a way to speficy which syscall
     args are pathnames and thus should be read using bpf_probe_read_str().
 
   - Skip unknown syscalls when expanding strace like syscall groups.
     This helps using the 'string' group of syscalls to work in arm64,
     where some of the syscalls present in x86_64 that deal with
     strings, for instance 'access', are deprecated and this should not
     be asked for tracing.
 
   Leo Yan:
 
   - Exit when failing to build eBPF program.
 
 perf config:
 
   Arnaldo Carvalho de Melo:
 
   - Bail out when a handler returns failure for a key-value pair. This
     helps with cases where processing a key-value pair is not just a
     matter of setting some tool specific knob, involving, for instance
     building a BPF program to then attach to the list of events 'perf
     trace' will use, e.g. augmented_raw_syscalls.c.
 
 perf.data:
 
   Kan Liang:
 
   - Read and store die ID information available in new Intel processors
     in CPUID.1F in the CPU topology written in the perf.data header.
 
 perf stat:
 
   Kan Liang:
 
   - Support per-die aggregation.
 
 Documentation:
 
   Arnaldo Carvalho de Melo:
 
   - Update perf.data documentation about the CPU_TOPOLOGY, MEM_TOPOLOGY,
     CLOCKID and DIR_FORMAT headers.
 
   Song Liu:
 
   - Add description of headers HEADER_BPF_PROG_INFO and HEADER_BPF_BTF.
 
   Leo Yan:
 
   - Update default value for llvm.clang-bpf-cmd-template in 'man perf-config'.
 
 JVMTI:
 
   Jiri Olsa:
 
   - Address gcc string overflow warning for strncpy()
 
 core:
 
   - Remove superfluous nthreads system_wide setup in perf_evsel__alloc_fd().
 
 Intel PT:
 
   Adrian Hunter:
 
   - Add support for samples to contain IPC ratio, collecting cycles
     information from CYC packets, showing the IPC info periodically, because
     Intel PT does not update the cycle count on every branch or instruction,
     the incremental values will often be zero.  When there are values, they
     will be the number of instructions and number of cycles since the last
     update, and thus represent the average IPC since the last IPC value.
 
     E.g.:
 
     # perf record --cpu 1 -m200000 -a -e intel_pt/cyc/u sleep 0.0001
     rounding mmap pages size to 1024M (262144 pages)
     [ perf record: Woken up 0 times to write data ]
     [ perf record: Captured and wrote 2.208 MB perf.data ]
     # perf script --insn-trace --xed -F+ipc,-dso,-cpu,-tid
     #
     <SNIP + add line numbering to make sense of IPC counts e.g.: (18/3)>
     1   cc1 63501.650479626: 7f5219ac27bf _int_free+0x3f   jnz 0x7f5219ac2af0       IPC: 0.81 (36/44)
     2   cc1 63501.650479626: 7f5219ac27c5 _int_free+0x45   cmp $0x1f, %rbp
     3   cc1 63501.650479626: 7f5219ac27c9 _int_free+0x49   jbe 0x7f5219ac2b00
     4   cc1 63501.650479626: 7f5219ac27cf _int_free+0x4f   test $0x8, %al
     5   cc1 63501.650479626: 7f5219ac27d1 _int_free+0x51   jnz 0x7f5219ac2b00
     6   cc1 63501.650479626: 7f5219ac27d7 _int_free+0x57   movq  0x13c58a(%rip), %rcx
     7   cc1 63501.650479626: 7f5219ac27de _int_free+0x5e   mov %rdi, %r12
     8   cc1 63501.650479626: 7f5219ac27e1 _int_free+0x61   movq  %fs:(%rcx), %rax
     9   cc1 63501.650479626: 7f5219ac27e5 _int_free+0x65   test %rax, %rax
    10   cc1 63501.650479626: 7f5219ac27e8 _int_free+0x68   jz 0x7f5219ac2821
    11   cc1 63501.650479626: 7f5219ac27ea _int_free+0x6a   leaq  -0x11(%rbp), %rdi
    12   cc1 63501.650479626: 7f5219ac27ee _int_free+0x6e   mov %rdi, %rsi
    13   cc1 63501.650479626: 7f5219ac27f1 _int_free+0x71   shr $0x4, %rsi
    14   cc1 63501.650479626: 7f5219ac27f5 _int_free+0x75   cmpq  %rsi, 0x13caf4(%rip)
    15   cc1 63501.650479626: 7f5219ac27fc _int_free+0x7c   jbe 0x7f5219ac2821
    16   cc1 63501.650479626: 7f5219ac2821 _int_free+0xa1   cmpq  0x13f138(%rip), %rbp
    17   cc1 63501.650479626: 7f5219ac2828 _int_free+0xa8   jnbe 0x7f5219ac28d8
    18   cc1 63501.650479626: 7f5219ac28d8 _int_free+0x158  testb  $0x2, 0x8(%rbx)
    19   cc1 63501.650479628: 7f5219ac28dc _int_free+0x15c  jnz 0x7f5219ac2ab0       IPC: 6.00 (18/3)
     <SNIP>
 
   - Allow using time ranges with Intel PT, i.e. these features, already
     present but not optimially usable with Intel PT, should be now:
 
         Select the second 10% time slice:
 
         $ perf script --time 10%/2
 
         Select from 0% to 10% time slice:
 
         $ perf script --time 0%-10%
 
         Select the first and second 10% time slices:
 
         $ perf script --time 10%/1,10%/2
 
         Select from 0% to 10% and 30% to 40% slices:
 
         $ perf script --time 0%-10%,30%-40%
 
 cs-etm (ARM):
 
   Mathieu Poirier:
 
   - Add support for CPU-wide trace scenarios.
 
 s390:
 
   Thomas Richter:
 
   - Fix missing kvm module load for s390.
 
   - Fix OOM error in TUI mode on s390
 
   - Support s390 diag event display when doing analysis on !s390
     architectures.
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo-5.3-20190611' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

perf record:

  Alexey Budankov:

  - Allow mixing --user-regs with --call-graph=dwarf, making sure that
    the minimal set of registers for DWARF unwinding is present in the
    set of user registers requested to be present in each sample, while
    warning the user that this may make callchains unreliable if more
    that the minimal set of registers is needed to unwind.

  yuzhoujian:

  - Add support to collect callchains from kernel or user space only,
    IOW allow setting the perf_event_attr.exclude_callchain_{kernel,user}
    bits from the command line.

perf trace:

  Arnaldo Carvalho de Melo:

  - Remove x86_64 specific syscall numbers from the augmented_raw_syscalls
    BPF in-kernel collector of augmented raw_syscalls:sys_{enter,exit}
    payloads, use instead the syscall numbers obtainer either by the
    arch specific syscalltbl generators or from audit-libs.

  - Allow 'perf trace' to ask for the number of bytes to collect for
    string arguments, for now ask for PATH_MAX, i.e. the whole
    pathnames, which ends up being just a way to speficy which syscall
    args are pathnames and thus should be read using bpf_probe_read_str().

  - Skip unknown syscalls when expanding strace like syscall groups.
    This helps using the 'string' group of syscalls to work in arm64,
    where some of the syscalls present in x86_64 that deal with
    strings, for instance 'access', are deprecated and this should not
    be asked for tracing.

  Leo Yan:

  - Exit when failing to build eBPF program.

perf config:

  Arnaldo Carvalho de Melo:

  - Bail out when a handler returns failure for a key-value pair. This
    helps with cases where processing a key-value pair is not just a
    matter of setting some tool specific knob, involving, for instance
    building a BPF program to then attach to the list of events 'perf
    trace' will use, e.g. augmented_raw_syscalls.c.

perf.data:

  Kan Liang:

  - Read and store die ID information available in new Intel processors
    in CPUID.1F in the CPU topology written in the perf.data header.

perf stat:

  Kan Liang:

  - Support per-die aggregation.

Documentation:

  Arnaldo Carvalho de Melo:

  - Update perf.data documentation about the CPU_TOPOLOGY, MEM_TOPOLOGY,
    CLOCKID and DIR_FORMAT headers.

  Song Liu:

  - Add description of headers HEADER_BPF_PROG_INFO and HEADER_BPF_BTF.

  Leo Yan:

  - Update default value for llvm.clang-bpf-cmd-template in 'man perf-config'.

JVMTI:

  Jiri Olsa:

  - Address gcc string overflow warning for strncpy()

core:

  - Remove superfluous nthreads system_wide setup in perf_evsel__alloc_fd().

Intel PT:

  Adrian Hunter:

  - Add support for samples to contain IPC ratio, collecting cycles
    information from CYC packets, showing the IPC info periodically, because
    Intel PT does not update the cycle count on every branch or instruction,
    the incremental values will often be zero.  When there are values, they
    will be the number of instructions and number of cycles since the last
    update, and thus represent the average IPC since the last IPC value.

    E.g.:

    # perf record --cpu 1 -m200000 -a -e intel_pt/cyc/u sleep 0.0001
    rounding mmap pages size to 1024M (262144 pages)
    [ perf record: Woken up 0 times to write data ]
    [ perf record: Captured and wrote 2.208 MB perf.data ]
    # perf script --insn-trace --xed -F+ipc,-dso,-cpu,-tid
    #
    <SNIP + add line numbering to make sense of IPC counts e.g.: (18/3)>
    1   cc1 63501.650479626: 7f5219ac27bf _int_free+0x3f   jnz 0x7f5219ac2af0       IPC: 0.81 (36/44)
    2   cc1 63501.650479626: 7f5219ac27c5 _int_free+0x45   cmp $0x1f, %rbp
    3   cc1 63501.650479626: 7f5219ac27c9 _int_free+0x49   jbe 0x7f5219ac2b00
    4   cc1 63501.650479626: 7f5219ac27cf _int_free+0x4f   test $0x8, %al
    5   cc1 63501.650479626: 7f5219ac27d1 _int_free+0x51   jnz 0x7f5219ac2b00
    6   cc1 63501.650479626: 7f5219ac27d7 _int_free+0x57   movq  0x13c58a(%rip), %rcx
    7   cc1 63501.650479626: 7f5219ac27de _int_free+0x5e   mov %rdi, %r12
    8   cc1 63501.650479626: 7f5219ac27e1 _int_free+0x61   movq  %fs:(%rcx), %rax
    9   cc1 63501.650479626: 7f5219ac27e5 _int_free+0x65   test %rax, %rax
   10   cc1 63501.650479626: 7f5219ac27e8 _int_free+0x68   jz 0x7f5219ac2821
   11   cc1 63501.650479626: 7f5219ac27ea _int_free+0x6a   leaq  -0x11(%rbp), %rdi
   12   cc1 63501.650479626: 7f5219ac27ee _int_free+0x6e   mov %rdi, %rsi
   13   cc1 63501.650479626: 7f5219ac27f1 _int_free+0x71   shr $0x4, %rsi
   14   cc1 63501.650479626: 7f5219ac27f5 _int_free+0x75   cmpq  %rsi, 0x13caf4(%rip)
   15   cc1 63501.650479626: 7f5219ac27fc _int_free+0x7c   jbe 0x7f5219ac2821
   16   cc1 63501.650479626: 7f5219ac2821 _int_free+0xa1   cmpq  0x13f138(%rip), %rbp
   17   cc1 63501.650479626: 7f5219ac2828 _int_free+0xa8   jnbe 0x7f5219ac28d8
   18   cc1 63501.650479626: 7f5219ac28d8 _int_free+0x158  testb  $0x2, 0x8(%rbx)
   19   cc1 63501.650479628: 7f5219ac28dc _int_free+0x15c  jnz 0x7f5219ac2ab0       IPC: 6.00 (18/3)
    <SNIP>

  - Allow using time ranges with Intel PT, i.e. these features, already
    present but not optimially usable with Intel PT, should be now:

        Select the second 10% time slice:

        $ perf script --time 10%/2

        Select from 0% to 10% time slice:

        $ perf script --time 0%-10%

        Select the first and second 10% time slices:

        $ perf script --time 10%/1,10%/2

        Select from 0% to 10% and 30% to 40% slices:

        $ perf script --time 0%-10%,30%-40%

cs-etm (ARM):

  Mathieu Poirier:

  - Add support for CPU-wide trace scenarios.

s390:

  Thomas Richter:

  - Fix missing kvm module load for s390.

  - Fix OOM error in TUI mode on s390

  - Support s390 diag event display when doing analysis on !s390
    architectures.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-06-17 20:48:14 +02:00
Thomas Gleixner 2025cf9e19 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 263 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00
Adrian Hunter 003ccdc716 perf thread-stack: Accumulate IPC information
Cycle and instruction counts are added to the stack. The IPC of a
function and all functions it calls, is also recorded.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190520113728.14389-14-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-06-05 09:47:57 -03:00
Adrian Hunter f435887ec0 perf db-export: Add calls parent_id to enable creation of call trees
The call_path can be used to find the parent symbol for a call but not
the exact parent call. To do that add parent_id to the call_return
export. This enables the creation of a call tree from the exported data.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lkml.kernel.org/n/tip-6j7tzdxo67cox6kan7k22oo6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-03-01 14:50:47 -03:00
Adrian Hunter f08046cb30 perf thread-stack: Represent jmps to the start of a different symbol
The compiler might optimize a call/ret combination by making it a jmp.
However the thread-stack does not presently cater for that, so that such
control flow is not visible in the call graph. Make it visible by
recording on the stack a branch to the start of a different symbol.
Note, that means when a ret pops the stack, all jmps must be popped off
first.

Example:

  $ cat jmp-to-fn.c
  __attribute__((noinline)) int bar(void)
  {
          return -1;
  }

  __attribute__((noinline)) int foo(void)
  {
          return bar() + 1;
  }

  int main()
  {
          return foo();
  }
  $ gcc -ggdb3 -Wall -Wextra -O2 -o jmp-to-fn jmp-to-fn.c
  $ objdump -d jmp-to-fn
  <SNIP>
  0000000000001040 <main>:
      1040:       31 c0                   xor    %eax,%eax
      1042:       e9 09 01 00 00          jmpq   1150 <foo>
  <SNIP>
  0000000000001140 <bar>:
      1140:       b8 ff ff ff ff          mov    $0xffffffff,%eax
      1145:       c3                      retq
  <SNIP>
  0000000000001150 <foo>:
      1150:       31 c0                   xor    %eax,%eax
      1152:       e8 e9 ff ff ff          callq  1140 <bar>
      1157:       83 c0 01                add    $0x1,%eax
      115a:       c3                      retq
  <SNIP>
  $ perf record -o jmp-to-fn.perf.data -e intel_pt/cyc/u ./jmp-to-fn
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0,017 MB jmp-to-fn.perf.data ]
  $ perf script -i jmp-to-fn.perf.data --itrace=be -s ~/libexec/perf-core/scripts/python/export-to-sqlite.py jmp-to-fn.db branches calls
  2019-01-08 13:24:58.783069 Creating database...
  2019-01-08 13:24:58.794650 Writing records...
  2019-01-08 13:24:59.008050 Adding indexes
  2019-01-08 13:24:59.015802 Done
  $  ~/libexec/perf-core/scripts/python/exported-sql-viewer.py jmp-to-fn.db

Before:

    main
        -> bar

After:

    main
        -> foo
            -> bar

Committer testing:

Install the python2-pyside package, then select these menu options
on the GUI:

   "Reports"
      "Context sensitive callgraphs"

Then go on expanding the symbols, to get, full picture when doing this
on a fedora:29 with gcc version 8.2.1 20181215 (Red Hat 8.2.1-6) (GCC):

jmp-to-fn
  PID:TID
    _start                (ld-2.28.so)
      __libc_start_main
        main
          foo
            bar

To verify that indeed, this fixes the problem.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190109091835.5570-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-02-06 10:00:40 -03:00
Adrian Hunter 256d92bc93 perf thread-stack: Fix thread stack processing for the idle task
perf creates a single 'struct thread' to represent the idle task. That
is because threads are identified by PID and TID, and the idle task
always has PID == TID == 0.

However, there are actually separate idle tasks for each CPU. That
creates a problem for thread stack processing which assumes that each
thread has a single stack, not one stack per CPU.

Fix that by passing through the CPU number, and in the case of the idle
"thread", pick the thread stack from an array based on the CPU number.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20181221120620.9659-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-01-02 11:03:17 -03:00
Adrian Hunter 242483068b perf intel-pt: Insert callchain context into synthesized callchains
In the absence of a fallback, callchains must encode also the callchain
context. Do that now there is no fallback.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: stable@vger.kernel.org # 4.19
Link: http://lkml.kernel.org/r/100ea2ec-ed14-b56d-d810-e0a6d2f4b069@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-10-31 12:54:27 -03:00
Adrian Hunter e216708d98 perf script: Add callindent option
Based on patches from Andi Kleen.

When printing PT instruction traces with perf script it is rather useful
to see some indentation for the call tree. This patch adds a new
callindent field to perf script that prints spaces for the function call
stack depth.

We already have code to track the function call stack for PT, that we
can reuse with minor modifications.

The resulting output is not quite as nice as ftrace yet, but a lot
better than what was there before.

Note there are some corner cases when the thread stack gets code
confused and prints incorrect indentation. Even with that it is fairly
useful.

When displaying kernel code traces it is recommended to run as root, as
otherwise perf doesn't understand the kernel addresses properly, and may
not reset the call stack correctly on kernel boundaries.

Example output:

	sudo perf-with-kcore record eg2 -a -e intel_pt// -- sleep 1
	sudo perf-with-kcore script eg2 --ns -F callindent,time,comm,pid,sym,ip,addr,flags,cpu --itrace=cre | less
	...
         swapper     0 [000]  5830.389116586:   call        irq_exit                                                     ffffffff8104d620 smp_call_function_single_interrupt+0x30 => ffffffff8107e720 irq_exit
         swapper     0 [000]  5830.389116586:   call            idle_cpu                                                 ffffffff8107e769 irq_exit+0x49 => ffffffff810a3970 idle_cpu
         swapper     0 [000]  5830.389116586:   return          idle_cpu                                                 ffffffff810a39b7 idle_cpu+0x47 => ffffffff8107e76e irq_exit
         swapper     0 [000]  5830.389116586:   call            tick_nohz_irq_exit                                       ffffffff8107e7bd irq_exit+0x9d => ffffffff810f2fc0 tick_nohz_irq_exit
         swapper     0 [000]  5830.389116919:   call                __tick_nohz_idle_enter                               ffffffff810f2fe0 tick_nohz_irq_exit+0x20 => ffffffff810f28d0 __tick_nohz_idle_enter
         swapper     0 [000]  5830.389116919:   call                    ktime_get                                        ffffffff810f28f1 __tick_nohz_idle_enter+0x21 => ffffffff810e9ec0 ktime_get
         swapper     0 [000]  5830.389116919:   call                        read_tsc                                     ffffffff810e9ef6 ktime_get+0x36 => ffffffff81035070 read_tsc
         swapper     0 [000]  5830.389116919:   return                      read_tsc                                     ffffffff81035084 read_tsc+0x14 => ffffffff810e9efc ktime_get
         swapper     0 [000]  5830.389116919:   return                  ktime_get                                        ffffffff810e9f46 ktime_get+0x86 => ffffffff810f28f6 __tick_nohz_idle_enter
         swapper     0 [000]  5830.389116919:   call                    sched_clock_idle_sleep_event                     ffffffff810f290b __tick_nohz_idle_enter+0x3b => ffffffff810a7380 sched_clock_idle_sleep_event
         swapper     0 [000]  5830.389116919:   call                        sched_clock_cpu                              ffffffff810a738b sched_clock_idle_sleep_event+0xb => ffffffff810a72e0 sched_clock_cpu
         swapper     0 [000]  5830.389116919:   call                            sched_clock                              ffffffff810a734d sched_clock_cpu+0x6d => ffffffff81035750 sched_clock
         swapper     0 [000]  5830.389116919:   call                                native_sched_clock                   ffffffff81035754 sched_clock+0x4 => ffffffff81035640 native_sched_clock
         swapper     0 [000]  5830.389116919:   return                              native_sched_clock                   ffffffff8103568c native_sched_clock+0x4c => ffffffff81035759 sched_clock
         swapper     0 [000]  5830.389116919:   return                          sched_clock                              ffffffff8103575c sched_clock+0xc => ffffffff810a7352 sched_clock_cpu
         swapper     0 [000]  5830.389116919:   return                      sched_clock_cpu                              ffffffff810a7356 sched_clock_cpu+0x76 => ffffffff810a7390 sched_clock_idle_sleep_event
         swapper     0 [000]  5830.389116919:   return                  sched_clock_idle_sleep_event                     ffffffff810a7391 sched_clock_idle_sleep_event+0x11 => ffffffff810f2910 __tick_nohz_idle_enter
	...

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1466689258-28493-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-23 17:04:26 -03:00
Chris Phlipot 2c15f5eb04 perf script: Expose usage of the callchain db export via the python api
This change allows python scripts to be able to utilize the recent
changes to the db export api allowing the export of call_paths derived
from sampled callchains. These call paths are also now associated with
the samples from which they were derived.

- This feature is enabled by setting "perf_db_export_callchains" to true

- When enabled, samples that have callchain information will have the
  callchains exported via call_path_table

- The call_path_id field is added to sample_table to enable association of
  samples with the corresponding callchain stored in the call paths
  table. A call_path_id of 0 will be exported if there is no
  corresponding callchain.

- When "perf_db_export_callchains" and "perf_db_export_calls" are both
  set to True, the call path root data structure will be shared. This
  prevents duplicating of data and call path ids that would result from
  building two separate call path trees in memory.

- The call_return_processor structure definition was relocated to the header
  file to make its contents visible to db-export.c. This enables the
  sharing of call path trees between the two features, as mentioned
  above.

This change is visible to python scripts using the python db export api.

The change is backwards compatible with scripts written against the
previous API, assuming that the scripts model the sample_table function
after the one in export-to-postgresql.py script by allowing for
additional arguments to be added in the future. ie. using *x as the
final argument of the sample_table function.

Signed-off-by: Chris Phlipot <cphlipot0@gmail.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461831551-12213-6-git-send-email-cphlipot0@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-06 13:00:54 -03:00
Chris Phlipot 451db12617 perf tools: Refactor code to move call path handling out of thread-stack
Move the call path handling code out of thread-stack.c and
thread-stack.h to allow other components that are not part of
thread-stack to create call paths.

Summary:

- Create call-path.c and call-path.h and add them to the build.

- Move all call path related code out of thread-stack.c and thread-stack.h
  and into call-path.c and call-path.h.

- A small subset of structures and functions are now visible through
  call-path.h, which is required for thread-stack.c to continue to
  compile.

This change is a prerequisite for subsequent patches in this change set
and by itself contains no user-visible changes.

Signed-off-by: Chris Phlipot <cphlipot0@gmail.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461831551-12213-3-git-send-email-cphlipot0@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-06 13:00:43 -03:00
Adrian Hunter a5499b3719 perf tools: Ensure thread-stack is flushed
The thread-stack represents a thread's current stack.  When a thread
exits there can still be many functions on the stack e.g. exit() can be
called many levels deep, so all the callers will never return.  To get
that information output, the thread-stack must be flushed.

Previously it was assumed the thread-stack would be flushed when the
struct thread was deleted.  With thread ref-counting it is no longer
clear when that will be, if ever. So instead explicitly flush all the
thread-stacks at the end of a session.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1432906425-9911-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-06-19 16:03:33 -03:00
Adrian Hunter 92a9e4f7db perf tools: Enhance the thread stack to output call/return data
Enhance the thread stack to output detailed information about paired
calls and returns.

The enhanced processing consumes sample information via
thread_stack__process() and outputs information about paired calls /
returns via a call-back.

While the call-back makes it possible for the facility to be used by
arbitrary tools, a subsequent patch will provide the information to
Python scripting via the db-export interface.

An important part of the call/return information is the
call path which provides a structure that defines a context
sensitive call graph.

Note that there are now two ways to use the thread stack.

For simply providing a call stack (like you would get from the perf
record -g option) the interface consists of thread_stack__event() and
thread_stack__sample().

Whereas the enhanced interface consists of call_return_processor__new()
and thread_stack__process().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1414678188-14946-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-11-03 17:43:56 -03:00
Adrian Hunter 00447ccdf3 perf tools: Add a thread stack for synthesizing call chains
Add a thread stack for synthesizing call chains from call and return
events.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1414678188-14946-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-11-03 17:10:59 -03:00