For X86, the var2_w field of PERF_SAMPLE_WEIGHT_STRUCT stands for the
instruction latency. Current perf forces the var2_w to the data->ins_lat
in the generic code. It works well for now because X86 is the only
architecture that supports the PERF_SAMPLE_WEIGHT_STRUCT, but it may
bring problems once other architectures support the sample type.  For
example, the var2_w may be used to capture something else on PowerPC.

Create two architecture specific functions to parse and synthesize the
weight related samples. Move the X86 specific codes to the X86 version
functions. Other architectures can implement their own functions later
separately.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/1612540912-6562-1-git-send-email-kan.liang@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Emitting a PSB+ can cause a CPU a slight delay. When doing timing analysis
of code with Intel PT, it is useful to know if a timing bubble was caused
by Intel PT or not. Add reporting of PSB events via perf script. PSB
events are printed with the existing itrace 'p' option which also prints
power and frequency changes. The PSB event contains the trace offset at
which the PSB occurs, to allow easy reference back to the PSB+ packets.

The PSB event timestamp is always the timestamp from the PSB+ TSC
packet, and the ip is always the address from the PSB+ FUP packet.

The code changes are non-trivial because the decoder must walk to the
PSB+ FUP address before outputting the PSB event.

Example:

  $ perf record -e intel_pt/cyc,psb_period=0/u uname
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.046 MB perf.data ]
  $ perf script --itrace=p --ns
     perf 17981 [006] 25617.510820383:  psb:  psb offs: 0                               0 [unknown] ([unknown])
     perf 17981 [006] 25617.510820383:  cbr:  cbr: 42 freq: 4219 MHz (156%)             0 [unknown] ([unknown])
    uname 17981 [006] 25617.510889753:  psb:  psb offs: 0xb50                7f78c12a212e __GI___tunables_init+0xee (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510899162:  psb:  psb offs: 0x12d0               7f78c128af1c dl_main+0x93c (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510939242:  psb:  psb offs: 0x1a50               7f78c128eefc _dl_map_object_from_fd+0x13c (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510981274:  psb:  psb offs: 0x21c8               7f78c1296307 _dl_relocate_object+0x927 (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510993034:  psb:  psb offs: 0x2948               7f78c12940e4 _dl_lookup_symbol_x+0x14 (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511003871:  psb:  psb offs: 0x30c8               7f78c12937b3 do_lookup_x+0x2f3 (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511019854:  psb:  psb offs: 0x3850               7f78c1295eed _dl_relocate_object+0x50d (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511029015:  psb:  psb offs: 0x4390               7f78c12a855a strcmp+0xf6a (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511064876:  psb:  psb offs: 0x4b10                          0 [unknown] ([unknown])
    uname 17981 [006] 25617.511080762:  psb:  psb offs: 0x5290               7f78c11db53d _dl_addr+0x13d (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511086035:  psb:  psb offs: 0x5a08               7f78c11db538 _dl_addr+0x138 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511091381:  psb:  psb offs: 0x6190               7f78c11db534 _dl_addr+0x134 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511096681:  psb:  psb offs: 0x6910               7f78c11db4c3 _dl_addr+0xc3 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511119520:  psb:  psb offs: 0x7090               7f78c10ada5e _nl_intern_locale_data+0x12e (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511126584:  psb:  psb offs: 0x7818               7f78c10ada50 _nl_intern_locale_data+0x120 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511132775:  psb:  psb offs: 0x8358               7f78c10c20c0 getenv+0xa0 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511134598:  psb:  psb offs: 0x8ad0               7f78c10ada09 _nl_intern_locale_data+0xd9 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511135685:  psb:  psb offs: 0x9258               7f78c10ada50 _nl_intern_locale_data+0x120 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511138322:  psb:  psb offs: 0x99d0               7f78c11fffd9 __strncmp_avx2+0x39 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511158907:  psb:  psb offs: 0xa150                          0 [unknown] ([unknown])
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210205175350.23817-5-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The code assumed every CYC-eligible packet has a CYC packet, which is not
the case when CYC thresholds are used. Fix by checking if a CYC packet is
actually present in that case.

Fixes: 5b1dc0fd ("perf intel-pt: Add support for samples to contain IPC ratio")
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210205175350.23817-4-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The code assumed a change in cycle count means accurate IPC. That is not
correct, for example when sampling both branches and instructions, or at
a FUP packet (which is not CYC-eligible) address. Fix by using an explicit
flag to indicate when IPC can be sampled.

Fixes: 5b1dc0fd ("perf intel-pt: Add support for samples to contain IPC ratio")
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20210205175350.23817-3-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add missing CYC packet processing when walking through PSB+. This
improves the accuracy of timestamps that follow PSB+, until the next
MTC.

Fixes: 3d498078 ("perf tools: Add new Intel PT packet definitions")
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: NAndi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210205175350.23817-2-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When locating the DWARF module for a given address, __find_debuginfo()
requires a 'struct dso' passed via the userdata argument.

However, this field is only set in __report_module() if the module is
found in via dwfl_addrmodule(), not if it is found later via
dwfl_report_elf().

Set userdata irrespective of how the DWARF module was found, as long as
we found a module.

Fixes: bf53fc6b ("perf unwind: Fix separate debug info files when using elfutils' libdw's unwinder")
Signed-off-by: NDave Rigby <d.rigby@me.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211801Acked-by: NJan Kratochvil <jan.kratochvil@redhat.com>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/linux-perf-users/20210218165654.36604-1-d.rigby@me.com/Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Commit da231338 ("perf record: Use an eventfd to wakeup when
done") uses eventfd() to solve a rare race where the setting and
checking of 'done' which add done_fd to pollfd.  When draining buffer,
revents of done_fd is 0 and evlist__filter_pollfd function returns a
non-zero value.  As a result, perf record does not stop profiling.

The following simple scenarios can trigger this condition:

  # sleep 10 &
  # perf record -p $!

After the sleep process exits, perf record should stop profiling and exit.
However, perf record keeps running.

If pollfd revents contains only POLLERR or POLLHUP, perf record
indicates that buffer is draining and need to stop profiling.  Use
fdarray_flag__nonfilterable() to set done eventfd to nonfilterable
objects, so that evlist__filter_pollfd() does not filter and check done
eventfd.

Fixes: da231338 ("perf record: Use an eventfd to wakeup when done")
Signed-off-by: NYang Jihong <yangjihong1@huawei.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: NJiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: zhangjinhao2@huawei.com
Link: http://lore.kernel.org/lkml/20210205065001.23252-1-yangjihong1@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fix the following coccicheck warnings:

./tools/perf/util/header.c:3809:18-20: WARNING !A || A && B is
equivalent to !A || B.
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/1612497255-87189-1-git-send-email-jiapeng.chong@linux.alibaba.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Eliminate the following coccicheck warning:
./tools/perf/util/metricgroup.c:382:3-4: Unneeded semicolon
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NYang Li <yang.lee@linux.alibaba.com>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yang li <yang.lee@linux.alibaba.com>
Link: http://lore.kernel.org/lkml/1612165277-95878-1-git-send-email-yang.lee@linux.alibaba.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Detect symbols generated by the OCaml compiler based on their prefix.

Demangle OCaml symbols, returning a newly allocated string (like the
existing Java demangling functionality).

Move a helper function (hex) from tests/code-reading.c to util/string.c

To test:

  echo 'Printf.printf "%d\n" (Random.int 42)' > test.ml
  perf record ocamlopt.opt test.ml
  perf report -d ocamlopt.opt
Signed-off-by: NFabian Hemmer <copy@copy.sh>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LPU-Reference: 20210203211537.b25ytjb6dq5jfbwx@nyu
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

With LTO, there are symbols like these:

/usr/lib/debug/usr/lib64/libantlr4-runtime.so.4.8-4.8-1.4.x86_64.debug
 10305: 0000000000955fa4     0 NOTYPE  LOCAL  DEFAULT   29 Predicate.cpp.2bc410e7

This comes from a runtime/debug split done by the standard way:

  objcopy --only-keep-debug $runtime $debug
  objcopy --add-gnu-debuglink=$debugfn -R .comment -R .GCC.command.line --strip-all $runtime

perf currently cannot resolve such symbols (relicts of LTO), as section
29 exists only in the debug file (29 is .debug_info). And perf resolves
symbols only against runtime file. This results in all symbols from such
a library being unresolved:

     0.38%  main2    libantlr4-runtime.so.4.8  [.] 0x00000000000671e0

So try resolving against the debug file first. And only if it fails (the
section has NOBITS set), try runtime file. We can do this, as "objcopy
--only-keep-debug" per documentation preserves all sections, but clears
data of some of them (the runtime ones) and marks them as NOBITS.

The correct result is now:
     0.38%  main2    libantlr4-runtime.so.4.8  [.] antlr4::IntStream::~IntStream

Note that these LTO symbols are properly skipped anyway as they belong
neither to *text* nor to *data* (is_label && !elf_sec__filter(&shdr,
secstrs) is true).
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210217122125.26416-1-jslaby@suse.czSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The sample structure contains the field 'data_src' which is used to
tell the data operation attributions, e.g. operation type is loading or
storing, cache level, it's snooping or remote accessing, etc.  At the
end, the 'data_src' will be parsed by perf mem/c2c tools to display
human readable strings.

This patch is to fill the 'data_src' field in the synthesized samples
base on different types.  Currently perf tool can display statistics for
L1/L2/L3 caches but it doesn't support the 'last level cache'.  To fit
to current implementation, 'data_src' field uses L3 cache for last level
cache.

Before this commit, perf mem report looks like this:
  # Samples: 75K of event 'l1d-miss'
  # Total weight : 75951
  # Sort order   : local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked
  #
  # Overhead  Samples  Local Weight  Memory access  Symbol                  Shared Object  Data Symbol             Data Object  Snoop  TLB access
  # ........  .......  ............  .............  ......................  .............  ......................  ...........  .....  ..........
  #
      81.56%    61945  0             N/A            [.] 0x00000000000009d8  serial_c       [.] 0000000000000000    [unknown]    N/A    N/A
      18.44%    14003  0             N/A            [.] 0x0000000000000828  serial_c       [.] 0000000000000000    [unknown]    N/A    N/A

Now on a system with Arm SPE, addresses and access types are displayed:

  # Samples: 75K of event 'l1d-miss'
  # Total weight : 75951
  # Sort order   : local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked
  #
  # Overhead  Samples  Local Weight  Memory access  Symbol                  Shared Object  Data Symbol             Data Object  Snoop  TLB access
  # ........  .......  ............  .............  ......................  .............  ......................  ...........  .....  ..........
  #
       0.43%      324  0             L1 miss        [.] 0x00000000000009d8  serial_c       [.] 0x0000ffff80794e00  anon         N/A    Walker hit
       0.42%      322  0             L1 miss        [.] 0x00000000000009d8  serial_c       [.] 0x0000ffff80794580  anon         N/A    Walker hit
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Reviewed-by: NJames Clark <james.clark@arm.com>
Tested-by: NJames Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <al.grant@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wei Li <liwei391@huawei.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: NJames Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20210211133856.2137-6-james.clark@arm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The memory event can deliver two benefits:

- The first benefit is the memory event can give out global view for
  memory accessing, rather than organizing events with scatter mode
  (e.g. uses separate event for L1 cache, last level cache, etc) which
  which can only display a event for single memory type, memory events
  include all memory accessing so it can display the data accessing
  cross memory levels in the same view;

- The second benefit is the sample generation might introduce a big
  overhead and need to wait for long time for Perf reporting, we can
  specify itrace option '--itrace=M' to filter out other events and only
  output memory events, this can significantly reduce the overhead
  caused by generating samples.

This patch is to enable memory event for Arm SPE.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Reviewed-by: NJames Clark <james.clark@arm.com>
Tested-by: NJames Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <al.grant@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wei Li <liwei391@huawei.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: NJames Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20210211133856.2137-5-james.clark@arm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To properly handle memory and branch samples, this patch divides into
two functions for generating samples: arm_spe__synth_mem_sample() is for
synthesizing memory and TLB samples; arm_spe__synth_branch_sample() is
to synthesize branch samples.

Arm SPE backend decoder has passed virtual and physical address through
packets, the address info is stored into the synthesize samples in the
function arm_spe__synth_mem_sample().

Committer notes:

Fixed this:

  36    46.77 fedora:27                     : FAIL clang version 5.0.2 (tags/RELEASE_502/final)

    util/arm-spe.c:269:34: error: missing field 'pid' initializer [-Werror,-Wmissing-field-initializers]
            struct perf_sample sample = { 0 };
                                            ^
    util/arm-spe.c:288:34: error: missing field 'pid' initializer [-Werror,-Wmissing-field-initializers]
            struct perf_sample sample = { 0 };

By using = { .ip = 0, };
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Reviewed-by: NJames Clark <james.clark@arm.com>
Tested-by: NJames Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <al.grant@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wei Li <liwei391@huawei.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: NJames Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20210211133856.2137-4-james.clark@arm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Perf failed to add a kretprobe event with debuginfo of vmlinux which is
compiled by gcc with -fpatchable-function-entry option enabled.  The
same issue with kernel module.

Issue:

  # perf probe  -v 'kernel_clone%return $retval'
  ......
  Writing event: r:probe/kernel_clone__return _text+599624 $retval
  Failed to write event: Invalid argument
    Error: Failed to add events. Reason: Invalid argument (Code: -22)

  # cat /sys/kernel/debug/tracing/error_log
  [156.75] trace_kprobe: error: Retprobe address must be an function entry
  Command: r:probe/kernel_clone__return _text+599624 $retval
                                        ^

  # llvm-dwarfdump  vmlinux |grep  -A 10  -w 0x00df2c2b
  0x00df2c2b:   DW_TAG_subprogram
                DW_AT_external  (true)
                DW_AT_name      ("kernel_clone")
                DW_AT_decl_file ("/home/code/linux-next/kernel/fork.c")
                DW_AT_decl_line (2423)
                DW_AT_decl_column       (0x07)
                DW_AT_prototyped        (true)
                DW_AT_type      (0x00dcd492 "pid_t")
                DW_AT_low_pc    (0xffff800010092648)
                DW_AT_high_pc   (0xffff800010092b9c)
                DW_AT_frame_base        (DW_OP_call_frame_cfa)

  # cat /proc/kallsyms |grep kernel_clone
  ffff800010092640 T kernel_clone
  # readelf -s vmlinux |grep -i kernel_clone
  183173: ffff800010092640  1372 FUNC    GLOBAL DEFAULT    2 kernel_clone

  # objdump -d vmlinux |grep -A 10  -w \<kernel_clone\>:
  ffff800010092640 <kernel_clone>:
  ffff800010092640:       d503201f        nop
  ffff800010092644:       d503201f        nop
  ffff800010092648:       d503233f        paciasp
  ffff80001009264c:       a9b87bfd        stp     x29, x30, [sp, #-128]!
  ffff800010092650:       910003fd        mov     x29, sp
  ffff800010092654:       a90153f3        stp     x19, x20, [sp, #16]

The entry address of kernel_clone converted by debuginfo is _text+599624
(0x92648), which is consistent with the value of DW_AT_low_pc attribute.
But the symbolic address of kernel_clone from /proc/kallsyms is
ffff800010092640.

This issue is found on arm64, -fpatchable-function-entry=2 is enabled when
CONFIG_DYNAMIC_FTRACE_WITH_REGS=y;
Just as objdump displayed the assembler contents of kernel_clone,
GCC generate 2 NOPs  at the beginning of each function.

kprobe_on_func_entry detects that (_text+599624) is not the entry address
of the function, which leads to the failure of adding kretprobe event.

  kprobe_on_func_entry
  ->_kprobe_addr
  ->kallsyms_lookup_size_offset
  ->arch_kprobe_on_func_entry		// FALSE

The cause of the issue is that the first instruction in the compile unit
indicated by DW_AT_low_pc does not include NOPs.
This issue exists in all gcc versions that support
-fpatchable-function-entry option.

I have reported it to the GCC community:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98776

Currently arm64 and PA-RISC may enable fpatchable-function-entry option.
The kernel compiled with clang does not have this issue.

FIX:

This GCC issue only cause the registration failure of the kretprobe event
which doesn't need debuginfo. So, stop using debuginfo for retprobe.
map will be used to query the probe function address.
Signed-off-by: NJianlin Lv <Jianlin.Lv@arm.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: clang-built-linux@googlegroups.com
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20210210062646.2377995-1-Jianlin.Lv@arm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The first time dso__load() was called on a PE file it always returned -1
error. This caused the first call to map__find_symbol() to always fail
on a PE file so the first sample from each PE file always had symbol
<unknown>. Subsequent samples succeed however because the DSO is already
loaded.

This fixes dso__load() to return 0 when successfully loading a DSO with
libbfd.

Fixes: eac9a434 ("perf symbols: Try reading the symbol table with libbfd")
Signed-off-by: NNicholas Fraser <nfraser@codeweavers.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Huw Davies <huw@codeweavers.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Remi Bernon <rbernon@codeweavers.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Tommi Rantala <tommi.t.rantala@nokia.com>
Cc: Ulrich Czekalla <uczekalla@codeweavers.com>
Link: http://lore.kernel.org/lkml/1671b43b-09c3-1911-dbf8-7f030242fbf7@codeweavers.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

dso__load_bfd_symbols() attempts to load a DSO at its original path,
then closes it and loads the file in the debug cache. This is incorrect.
It should ignore the original file and work with only the debug cache.

The original file may have changed or may not even exist, for example if
the debug cache has been transferred to another machine via "perf
archive".

This fix makes it only load the file in the debug cache.

Further notes from Nicholas:

dso__load_bfd_symbols() is called in a loop from dso__load() for a variety
of paths. These are generated by the various DSO_BINARY_TYPEs in the
binary_type_symtab list at the top of util/symbol.c. In each case the
debugfile passed to dso__load_bfd_symbols() is the path to try.

One of those iterations (the first one I believe) passes the original path
as the debugfile. If the file still exists at the original path, this is
the one that ends up being used in case the debugcache was deleted or the
PE file doesn't have a build-id.

A later iteration (BUILD_ID_CACHE) passes debugfile as the file in the
debugcache if it has a build-id. Even if the file was previously loaded at
its original path, (if I understand correctly) this load will override it
so the debugcache file ends up being used.

Committer notes:

So if it fails to find in the cache, it will eventually hope for the
best and look at the path in the local filesystem, which in many cases
is enough.

At some point we need to switch from this "hope for the best" approach
to one that warns the user that there is no guarantee, if no buildid is
present, that just by looking at the pathname the symbolisation will
work.
Signed-off-by: NNicholas Fraser <nfraser@codeweavers.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Huw Davies <huw@codeweavers.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Remi Bernon <rbernon@codeweavers.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Tommi Rantala <tommi.t.rantala@nokia.com>
Cc: Ulrich Czekalla <uczekalla@codeweavers.com>
Link: http://lore.kernel.org/lkml/e58e1237-94ab-e1c9-a7b9-473531906954@codeweavers.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch is to store operation type in packet structure.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Reviewed-by: NJames Clark <james.clark@arm.com>
Tested-by: NJames Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <al.grant@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wei Li <liwei391@huawei.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: NJames Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20210211133856.2137-3-james.clark@arm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch is to store virtual and physical memory addresses in packet,
which will be used for memory samples.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Reviewed-by: NJames Clark <james.clark@arm.com>
Tested-by: NJames Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <al.grant@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wei Li <liwei391@huawei.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210211133856.2137-2-james.clark@arm.comSigned-off-by: NJames Clark <james.clark@arm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch is to enable sample type PERF_SAMPLE_DATA_SRC for Arm SPE in
the perf data, when output the tracing data, it tells tools that it
contains data source in the memory event.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Reviewed-by: NJames Clark <james.clark@arm.com>
Tested-by: NJames Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <al.grant@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wei Li <liwei391@huawei.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210211133856.2137-1-james.clark@arm.comSigned-off-by: NJames Clark <james.clark@arm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Minor cleanup.
Signed-off-by: NIan Rogers <irogers@google.com>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210211183914.4093187-1-irogers@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Migrated to libperf in:

  4b247fa7 ("libperf: Adopt xyarray class from perf")
Signed-off-by: NIan Rogers <irogers@google.com>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210212043803.365993-1-irogers@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

GCC (GCC) 8.4.0 20200304 fails to build perf with:
: util/symbol.c: In function 'dso__load_bfd_symbols':
: util/symbol.c:1626:16: error: comparison of integer expressions of different signednes
:   for (i = 0; i < symbols_count; ++i) {
:                 ^
: util/symbol.c:1632:16: error: comparison of integer expressions of different signednes
:    while (i + 1 < symbols_count &&
:                 ^
: util/symbol.c:1637:13: error: comparison of integer expressions of different signednes
:    if (i + 1 < symbols_count &&
:              ^
: cc1: all warnings being treated as errors

It's unlikely that the symtable will be that big, but the fix is an
oneliner and as perf has CORE_CFLAGS += -Wextra, which makes build to
fail together with CORE_CFLAGS += -Werror

Fixes: eac9a434 ("perf symbols: Try reading the symbol table with libbfd")
Signed-off-by: NDmitry Safonov <dima@arista.com>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Jacek Caban <jacek@codeweavers.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Remi Bernon <rbernon@codeweavers.com>
Link: http://lore.kernel.org/lkml/20210209145148.178702-1-dima@arista.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Considering the following testcase:

  int
  foo(int a, int b)
  {
     for (unsigned i = 0; i < 1000000000; i++)
       a += b;
     return a;
  }

  int main()
  {
     foo (3, 4);
     return 0;
  }

'perf annotate' displays:

  86.52 │40055e: → ja   40056c <foo(int, int)+0x26>
  13.37 │400560:   mov  -0x18(%rbp),%eax
        │400563:   add  %eax,-0x14(%rbp)
        │400566:   addl $0x1,-0x4(%rbp)
   0.11 │40056a: → jmp  400557 <foo(int, int)+0x11>
        │40056c:   mov  -0x14(%rbp),%eax
        │40056f:   pop  %rbp

and the 'ja 40056c' does not link to the location in the function.  It's
caused by fact that comma is wrongly parsed, it's part of function
signature.

With my patch I see:

  86.52 │   ┌──ja   26
  13.37 │   │  mov  -0x18(%rbp),%eax
        │   │  add  %eax,-0x14(%rbp)
        │   │  addl $0x1,-0x4(%rbp)
   0.11 │   │↑ jmp  11
        │26:└─→mov  -0x14(%rbp),%eax

and 'o' output prints:

  86.52 │4005┌── ↓ ja   40056c <foo(int, int)+0x26>
  13.37 │4005│0:   mov  -0x18(%rbp),%eax
        │4005│3:   add  %eax,-0x14(%rbp)
        │4005│6:   addl $0x1,-0x4(%rbp)
   0.11 │4005│a: ↑ jmp  400557 <foo(int, int)+0x11>
        │4005└─→   mov  -0x14(%rbp),%eax

On the contrary, compiling the very same file with gcc -x c, the parsing
is fine because function arguments are not displayed:

  jmp  400543 <foo+0x1d>

Committer testing:

Before:

  $ cat cpp_args_annotate.c
  int
  foo(int a, int b)
  {
     for (unsigned i = 0; i < 1000000000; i++)
       a += b;
     return a;
  }

  int main()
  {
     foo (3, 4);
     return 0;
  }
  $ gcc --version |& head -1
  gcc (GCC) 10.2.1 20201125 (Red Hat 10.2.1-9)
  $ gcc -g cpp_args_annotate.c -o cpp_args_annotate
  $ perf record ./cpp_args_annotate
  [ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 0.275 MB perf.data (7188 samples) ]
  $ perf annotate --stdio2 foo
  Samples: 7K of event 'cycles:u', 4000 Hz, Event count (approx.): 7468429289, [percent: local period]
  foo() /home/acme/c/cpp_args_annotate
  Percent
              0000000000401106 <foo>:
              foo():
              int
              foo(int a, int b)
              {
                push %rbp
                mov  %rsp,%rbp
                mov  %edi,-0x14(%rbp)
                mov  %esi,-0x18(%rbp)
              for (unsigned i = 0; i < 1000000000; i++)
                movl $0x0,-0x4(%rbp)
              ↓ jmp  1d
              a += b;
   13.45  13:   mov  -0x18(%rbp),%eax
                add  %eax,-0x14(%rbp)
              for (unsigned i = 0; i < 1000000000; i++)
                addl $0x1,-0x4(%rbp)
    0.09  1d:   cmpl $0x3b9ac9ff,-0x4(%rbp)
   86.46      ↑ jbe  13
              return a;
                mov  -0x14(%rbp),%eax
              }
                pop  %rbp
              ← retq
  $

I.e. works for C, now lets switch to C++:

  $ g++ -g cpp_args_annotate.c -o cpp_args_annotate
  $ perf record ./cpp_args_annotate
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.268 MB perf.data (6976 samples) ]
  $ perf annotate --stdio2 foo
  Samples: 6K of event 'cycles:u', 4000 Hz, Event count (approx.): 7380681761, [percent: local period]
  foo() /home/acme/c/cpp_args_annotate
  Percent
              0000000000401106 <foo(int, int)>:
              foo(int, int):
              int
              foo(int a, int b)
              {
                push %rbp
                mov  %rsp,%rbp
                mov  %edi,-0x14(%rbp)
                mov  %esi,-0x18(%rbp)
              for (unsigned i = 0; i < 1000000000; i++)
                movl $0x0,-0x4(%rbp)
                cmpl $0x3b9ac9ff,-0x4(%rbp)
   86.53      → ja   40112c <foo(int, int)+0x26>
              a += b;
   13.32        mov  -0x18(%rbp),%eax
    0.00        add  %eax,-0x14(%rbp)
              for (unsigned i = 0; i < 1000000000; i++)
                addl $0x1,-0x4(%rbp)
    0.15      → jmp  401117 <foo(int, int)+0x11>
              return a;
                mov  -0x14(%rbp),%eax
              }
                pop  %rbp
              ← retq
  $

Reproduced.

Now with this patch:

Reusing the C++ built binary, as we can see here:

  $ readelf -wi cpp_args_annotate | grep producer
    <c>   DW_AT_producer    : (indirect string, offset: 0x2e): GNU C++14 10.2.1 20201125 (Red Hat 10.2.1-9) -mtune=generic -march=x86-64 -g
  $

And furthermore:

  $ file cpp_args_annotate
  cpp_args_annotate: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=4fe3cab260204765605ec630d0dc7a7e93c361a9, for GNU/Linux 3.2.0, with debug_info, not stripped
  $ perf buildid-list -i cpp_args_annotate
  4fe3cab260204765605ec630d0dc7a7e93c361a9
  $ perf buildid-list | grep cpp_args_annotate
  4fe3cab260204765605ec630d0dc7a7e93c361a9 /home/acme/c/cpp_args_annotate
  $

It now works:

  $ perf annotate --stdio2 foo
  Samples: 6K of event 'cycles:u', 4000 Hz, Event count (approx.): 7380681761, [percent: local period]
  foo() /home/acme/c/cpp_args_annotate
  Percent
              0000000000401106 <foo(int, int)>:
              foo(int, int):
              int
              foo(int a, int b)
              {
                push %rbp
                mov  %rsp,%rbp
                mov  %edi,-0x14(%rbp)
                mov  %esi,-0x18(%rbp)
              for (unsigned i = 0; i < 1000000000; i++)
                movl $0x0,-0x4(%rbp)
          11:   cmpl $0x3b9ac9ff,-0x4(%rbp)
   86.53      ↓ ja   26
              a += b;
   13.32        mov  -0x18(%rbp),%eax
    0.00        add  %eax,-0x14(%rbp)
              for (unsigned i = 0; i < 1000000000; i++)
                addl $0x1,-0x4(%rbp)
    0.15      ↑ jmp  11
              return a;
          26:   mov  -0x14(%rbp),%eax
              }
                pop  %rbp
              ← retq
  $
Signed-off-by: NMartin Liška <mliska@suse.cz>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Link: http://lore.kernel.org/lkml/13e1a405-edf9-e4c2-4327-a9b454353730@suse.czSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

As started by commit 05a5f51c ("Documentation: Replace lkml.org
links with lore"), replace lkml.org links with lore to better use a
single source that's more likely to stay available long-term.
Signed-off-by: NKees Kook <keescook@chromium.org>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Kook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: http://lore.kernel.org/lkml/20210210234220.2401035-1-keescook@chromium.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

'perf script' supports '-S' or '--symbol' options to only list the
records for these symbols. A symbol is typically a name or hex address.
If it's hex address, it is the start address of one symbol.

While it would be useful if we can filter trace records by any hex
address (not only the start address of symbol). So now we support
filtering trace records by more conditions, such as:

- symbol name
- start address of symbol
- any hexadecimal address
- address range

The comparison order is defined as:

1. symbol name comparison
2. symbol start address comparison.
3. any hexadecimal address comparison.
4. address range comparison.

The idea is if we can get a valid address from -S list, we add the
address to addr_list for address comparison otherwise we still leave
it to sym_list for symbol comparison.

Some examples:

  root@kbl-ppc:~# ./perf script -S ffffffff9a477308
            perf  8562 [000] 347303.578858:          1   cycles:  ffffffff9a477308 native_write_msr+0x8 ([kernel.kallsyms])
            perf  8562 [000] 347303.578860:          1   cycles:  ffffffff9a477308 native_write_msr+0x8 ([kernel.kallsyms])
            perf  8562 [000] 347303.578861:         11   cycles:  ffffffff9a477308 native_write_msr+0x8 ([kernel.kallsyms])
            perf  8562 [001] 347303.578903:          1   cycles:  ffffffff9a477308 native_write_msr+0x8 ([kernel.kallsyms])
            perf  8562 [001] 347303.578905:          1   cycles:  ffffffff9a477308 native_write_msr+0x8 ([kernel.kallsyms])
            perf  8562 [001] 347303.578906:         15   cycles:  ffffffff9a477308 native_write_msr+0x8 ([kernel.kallsyms])
            perf  8562 [002] 347303.578952:          1   cycles:  ffffffff9a477308 native_write_msr+0x8 ([kernel.kallsyms])
            perf  8562 [002] 347303.578953:          1   cycles:  ffffffff9a477308 native_write_msr+0x8 ([kernel.kallsyms])

Filter the traced records by hex address ffffffff9a477308.

  root@kbl-ppc:~# ./perf script -S ffffffff9a4dd4ce,ffffffff9a4d2de9,ffffffff9a6bf9f4
            perf  8562 [001] 347303.578911:     311706   cycles:  ffffffff9a6bf9f4 __kmalloc_node+0x204 ([kernel.kallsyms])
            perf  8562 [002] 347303.578960:     354477   cycles:  ffffffff9a4d2de9 sched_setaffinity+0x49 ([kernel.kallsyms])
            perf  8562 [003] 347303.579015:     450958   cycles:  ffffffff9a4dd4ce dequeue_task_fair+0x1ae ([kernel.kallsyms])

Filter the traced records by hex address ffffffff9a4dd4ce, ffffffff9a4d2de9, ffffffff9a6bf9f4.

  root@kbl-ppc:~# ./perf script -S ffffffff9a477309 --addr-range 16
            perf  8562 [000] 347303.578863:        291   cycles:  ffffffff9a47730a native_write_msr+0xa ([kernel.kallsyms])
            perf  8562 [001] 347303.578907:        411   cycles:  ffffffff9a47730a native_write_msr+0xa ([kernel.kallsyms])
            perf  8562 [002] 347303.578956:        462   cycles:  ffffffff9a47730f native_write_msr+0xf ([kernel.kallsyms])
            perf  8562 [003] 347303.579010:        497   cycles:  ffffffff9a47730f native_write_msr+0xf ([kernel.kallsyms])
            perf  8562 [004] 347303.579059:        429   cycles:  ffffffff9a47730f native_write_msr+0xf ([kernel.kallsyms])
            perf  8562 [005] 347303.579109:        408   cycles:  ffffffff9a47730a native_write_msr+0xa ([kernel.kallsyms])
            perf  8562 [006] 347303.579159:        460   cycles:  ffffffff9a47730f native_write_msr+0xf ([kernel.kallsyms])
            perf  8562 [007] 347303.579213:        436   cycles:  ffffffff9a47730f native_write_msr+0xf ([kernel.kallsyms])

Filter the traced records from address range [ffffffff9a477309, ffffffff9a477309 + 15].

  root@kbl-ppc:~# ./perf script -S "ffffffff9b163046,rcu_nmi_exit"
            perf  8562 [004] 347303.579060:      12013   cycles:  ffffffff9b163046 exc_nmi+0x166 ([kernel.kallsyms])
            perf  8562 [007] 347303.579214:      12138   cycles:  ffffffff9b165944 rcu_nmi_exit+0x34 ([kernel.kallsyms])

Filter by address + symbol
Signed-off-by: NJin Yao <yao.jin@linux.intel.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210207080935.31784-2-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This is to let intlist support addresses as its payload.

One potential problem is it can't support negative number. But so far,
there is no such kind of use case.
Signed-off-by: NJin Yao <yao.jin@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210207080935.31784-1-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

ftw() has been obsolete for about 12 years now.

Committer notes:

Further notes provided by the patch author:

    "NOTE: Not runtime-tested, I have no idea what I need to do in perf
     to test this. But at least it compiles now with my uClibc-based
     toolchain."

I looked at the nftw()/ftw() man page and for the use made with cgroups
in 'perf stat' the end result is equivalent.

Fixes: bb1c15b6 ("perf stat: Support regex pattern in --for-each-cgroup")
Signed-off-by: NPaul Cercueil <paul@crapouillou.net>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: od@zcrc.me
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20210208181157.1324550-1-paul@crapouillou.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The TMA method level 2 metrics is supported from the Intel Sapphire
Rapids server, which expose four L2 Topdown metrics events to user
space. There are eight L2 events in total. The other four L2 Topdown
metrics events are calculated from the corresponding L1 and the exposed
L2 events.

Now, the --topdown prints the complete top-down metrics that supported
by the CPU. For the Intel Sapphire Rapids server, there are 4 L1 events
and 8 L2 events displyed in one line.

Add a new option, --td-level, to display the top-down statistics that
equal to or lower than the input level.

The L2 event is marked only when both its L1 parent event and itself
crosse the threshold.

Here is an example:

  $ perf stat --topdown --td-level=2 --no-metric-only sleep 1
  Topdown accuracy may decrease when measuring long periods.
  Please print the result regularly, e.g. -I1000

  Performance counter stats for 'sleep 1':

     16,734,390   slots
      2,100,001   topdown-retiring       # 12.6% retiring
      2,034,376   topdown-bad-spec       # 12.3% bad speculation
      4,003,128   topdown-fe-bound       # 24.1% frontend bound
        328,125   topdown-heavy-ops      #  2.0% heavy operations    #  10.6% light operations
      1,968,751   topdown-br-mispredict  # 11.9% branch mispredict   #  0.4% machine clears
      2,953,127   topdown-fetch-lat      # 17.8% fetch latency       #  6.3% fetch bandwidth
      5,906,255   topdown-mem-bound      # 35.6% memory bound        #  15.4% core bound
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/1612296553-21962-9-git-send-email-kan.liang@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The instruction latency information can be recorded on some platforms,
e.g., the Intel Sapphire Rapids server. With both memory latency
(weight) and the new instruction latency information, users can easily
locate the expensive load instructions, and also understand the time
spent in different stages. The users can optimize their applications in
different pipeline stages.

The 'weight' field is shared among different architectures. Reusing the
'weight' field may impacts other architectures. Add a new field to store
the instruction latency.

Like the 'weight' support, introduce a 'ins_lat' for the global
instruction latency, and a 'local_ins_lat' for the local instruction
latency version.

Add new sort functions, INSTR Latency and Local INSTR Latency,
accordingly.

Add local_ins_lat to the default_mem_sort_order[].
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/1612296553-21962-7-git-send-email-kan.liang@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The new sample type, PERF_SAMPLE_WEIGHT_STRUCT, is an alternative of the
PERF_SAMPLE_WEIGHT sample type. Users can apply either the
PERF_SAMPLE_WEIGHT sample type or the PERF_SAMPLE_WEIGHT_STRUCT sample
type to retrieve the sample weight, but they cannot apply both sample
types simultaneously.

The new sample type shares the same space as the PERF_SAMPLE_WEIGHT
sample type. The lower 32 bits are exactly the same for both sample
type. The higher 32 bits may be different for different architecture.

Add arch specific arch_evsel__set_sample_weight() to set the new sample
type for X86. Only store the lower 32 bits for the sample->weight if the
new sample type is applied. In practice, no memory access could last
than 4G cycles. No data will be lost.

If the kernel doesn't support the new sample type. Fall back to the
PERF_SAMPLE_WEIGHT sample type.

There is no impact for other architectures.

Committer notes:

Fixup related to PERF_SAMPLE_CODE_PAGE_SIZE, present in acme/perf/core
but not upstream yet.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/1612296553-21962-6-git-send-email-kan.liang@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

'perf c2c' is also a memory profiling tool. Apply the two new data
source fields to 'perf c2c' as well.

Extend 'perf c2c' to display the number of loads which blocked by data or
address conflict.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/1612296553-21962-5-git-send-email-kan.liang@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Two new data source fields, to indicate the block reasons of a load
instruction, are introduced on the Intel Sapphire Rapids server. The
fields can be used by the memory profiling.

Add a new sort function, SORT_MEM_BLOCKED, for the two fields.

For the previous platforms or the block reason is unknown, print "N/A"
for the block reason.

Add blocked as a default mem sort key for perf report and perf mem
report.

Committer testing:

So in machines without this capability we get a "N/A" filling the new "Blocked"
column:

  $ perf mem record ls
  arch     certs	 CREDITS  Documentation  include  ipc     Kconfig  lib       MAINTAINERS  mm   samples  security  usr    block
  COPYING	 crypto	 drivers  fs             init     Kbuild  kernel   LICENSES  Makefile     net  README   scripts   sound  tools
  virt
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.008 MB perf.data (17 samples) ]
  $
  $ perf mem report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Total Lost Samples: 0
  #
  # Samples: 6  of event 'cpu/mem-loads,ldlat=30/Pu'
  # Total weight : 1381
  # Sort order   : local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked,blocked
  #
  # Overhead  Samples  Local Weight  Memory access         Symbol                   Shared Object  Data Symbol             Data Object   Snoop  TLB access    Locked  Blocked
  # ........  .......  ............  ....................  .......................  .............  ......................  ............  .....  ............  ......  .......
  #
      32.87%        1  454           Local RAM or RAM hit  [.] _dl_relocate_object  ld-2.31.so     [.] 0x00007fe91cef3078  libc-2.31.so  Hit    L1 or L2 hit  No       N/A
      25.56%        1  353           LFB or LFB hit        [.] strcmp               ld-2.31.so     [.] 0x00005586973855ca  ls            None   L1 or L2 hit  No       N/A
      22.59%        1  312           LFB or LFB hit        [.] _dl_cache_libcmp     ld-2.31.so     [.] 0x00007fe91d0e3b18  ld.so.cache   None   L1 or L2 hit  No       N/A
       8.47%        1  117           LFB or LFB hit        [.] _dl_relocate_object  ld-2.31.so     [.] 0x00007fe91ceee570  libc-2.31.so  None   L1 or L2 hit  No       N/A
       6.88%        1  95            LFB or LFB hit        [.] _dl_relocate_object  ld-2.31.so     [.] 0x00007fe91ceed490  libc-2.31.so  None   L1 or L2 hit  No       N/A
       3.62%        1  50            LFB or LFB hit        [.] _dl_cache_libcmp     ld-2.31.so     [.] 0x00007fe91d0ebe60  ld.so.cache   None   L1 or L2 hit  No       N/A

  # Samples: 11  of event 'cpu/mem-stores/Pu'
  # Total weight : 11
  # Sort order   : local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked,blocked
  #
  # Overhead  Samples  Local Weight  Memory access  Symbol                   Shared Object  Data Symbol             Data Object  Snoop  TLB access  Locked  Blocked
  # ........  .......  ............  .............  .......................  .............  ......................  ...........  .....  ..........  ......  .......
  #
       9.09%        1  0             L1 hit         [.] __strcoll_l          libc-2.31.so   [.] 0x00007fffe5648fc8  [stack]      N/A    N/A         N/A      N/A
       9.09%        1  0             L1 hit         [.] _dl_lookup_symbol_x  ld-2.31.so     [.] 0x00007fffe56490b8  [stack]      N/A    N/A         N/A      N/A
       9.09%        1  0             L1 hit         [.] _dl_name_match_p     ld-2.31.so     [.] 0x00007fffe56487d8  [stack]      N/A    N/A         N/A      N/A
       9.09%        1  0             L1 hit         [.] _dl_start            ld-2.31.so     [.] start_time+0x0      ld-2.31.so   N/A    N/A         N/A      N/A
       9.09%        1  0             L1 hit         [.] _dl_sysdep_start     ld-2.31.so     [.] 0x00007fffe56494b8  [stack]      N/A    N/A         N/A      N/A
       9.09%        1  0             L1 hit         [.] do_lookup_x          ld-2.31.so     [.] 0x00007fffe5648ff8  [stack]      N/A    N/A         N/A      N/A
       9.09%        1  0             L1 hit         [.] do_lookup_x          ld-2.31.so     [.] 0x00007fffe5649064  [stack]      N/A    N/A         N/A      N/A
       9.09%        1  0             L1 hit         [.] do_lookup_x          ld-2.31.so     [.] 0x00007fffe5649130  [stack]      N/A    N/A         N/A      N/A
       9.09%        1  0             L1 miss        [.] _dl_start            ld-2.31.so     [.] _rtld_global+0xaf8  ld-2.31.so   N/A    N/A         N/A      N/A
       9.09%        1  0             L1 miss        [.] _dl_start            ld-2.31.so     [.] _rtld_global+0xc28  ld-2.31.so   N/A    N/A         N/A      N/A
       9.09%        1  0             L1 miss        [.] _dl_start            ld-2.31.so     [.] 0x00007fffe56495b8  [stack]      N/A    N/A         N/A      N/A

  # (Tip: Show user configuration overrides: perf config --user --list)
  $
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/1612296553-21962-4-git-send-email-kan.liang@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

On the Intel Sapphire Rapids server, an auxiliary event has to be
enabled simultaneously with the load latency event to retrieve complete
Memory Info.

Add X86 specific perf_mem_events__name() to handle the auxiliary event.

- Users are only interested in the samples of the mem-loads event.
  Sample read the auxiliary event.

- The auxiliary event must be in front of the load latency event in a
  group. Assume the second event to sample if the auxiliary event is the
  leader.

- Add a weak is_mem_loads_aux_event() to check the auxiliary event for
  X86. For other ARCHs, it always return false.

Parse the unique event name, mem-loads-aux, for the auxiliary event.

Committer notes:

According to 61b985e3 ("perf/x86/intel: Add perf core PMU
support for Sapphire Rapids"), ENODATA is only returned by
sys_perf_event_open() when used with these auxiliary events, with this
in evsel__open_strerror():

       case ENODATA:
               return scnprintf(msg, size, "Cannot collect data source with the load latency event alone. "
                                "Please add an auxiliary event in front of the load latency event.");

This is Ok at this point in time, but fragile long term, I pointed this
out in the e-mail thread, requesting a follow up patch to check if
ENODATA is really for this specific case.

Fixed up sizeof(MEM_LOADS_AUX_NAME) bug pointed out by Namhyung.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210205152648.GC920417@kernel.org
Link: http://lore.kernel.org/lkml/1612296553-21962-3-git-send-email-kan.liang@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

if dwarf_offdie() returns NULL, the continue statement forces the next
iteration of the loop without updating the 'off' variable. It will cause
an endless loop in the process of traversing the compile unit.  So add
exception protection for looping CUs.
Signed-off-by: NJianlin Lv <Jianlin.Lv@arm.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: jianlin.lv@arm.com
Link: http://lore.kernel.org/lkml/20210203145702.1219509-1-Jianlin.Lv@arm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Avoid a naming conflict with for_each_event with similar code in
parse-events.c, rename to for_each_event_tps.
Signed-off-by: NIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210203052659.2975736-1-irogers@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch fixes "perf inject --jit" to properly operate on
namespaced/containerized processes:

* jitdump files are generated by the process, thus they should be
  looked up in its mount NS.

* DSOs of injected MMAP events will later be looked up in the process
  mount NS, so write them into its NS.

* PIDs & TIDs from jitdump events need to be translated to the PID as
  seen by "perf record" before written into MMAP events.

For a process in a different PID NS, the TID & PID given in the jitdump
event are actually ignored; I use the TID & PID of the thread which
mmap()ed the jitdump file. This is simplified and won't do for forks of
the initial process, if they continue using the same jitdump file.
Future patches might improve it.

This was tested by recording a NodeJS process running with
"--perf-prof", inside a Docker container, and by recording another
NodeJS process running in the same namespaces as perf itself, to make
sure it's not broken for non-containerized processes.
Signed-off-by: NYonatan Goldschmidt <yonatan.goldschmidt@granulate.io>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20201105015604.1726943-1-yonatan.goldschmidt@granulate.ioSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Provides an accurate mean to determine if the owner thread is in a
different PID namespace.
Signed-off-by: NYonatan Goldschmidt <yonatan.goldschmidt@granulate.io>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20201105015418.1725218-1-yonatan.goldschmidt@granulate.ioSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Like in __event__synthesize_thread(), I think it's better to use
scandir() instead of the readdir() loop.  In case some malicious task
continues to create new threads, the readdir() loop will run over and
over to collect tids.  The scandir() also has the problem but the window
is much smaller since it doesn't do much work during the iteration.

Also add filter_task() function as we only care the tasks.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210202090118.2008551-4-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To synthesize information to resolve sample IPs, it needs to scan task
and mmap info from the /proc filesystem.  For each process, it opens
(and reads) status and maps file respectively.  But as kernel threads
don't have memory maps so we can skip the maps file.

To find kernel threads, check "VmPeak:" line in /proc/<PID>/status file.
It's about the peak virtual memory usage so only user-level tasks have
that.  Note that it's possible to miss the line due to partial reads.
So we should double-check if it's a really kernel thread when there's no
VmPeak line.

Thus check "Threads:" line (which follows the VmPeak line whether or not
it exists) to be sure it's read enough data - just in case of deeply
nested pid namespaces or large number of supplementary groups are
involved.

This is for user process:

  $ head -40 /proc/1/status
  Name:	systemd
  Umask:	0000
  State:	S (sleeping)
  Tgid:	1
  Ngid:	0
  Pid:	1
  PPid:	0
  TracerPid:	0
  Uid:	0	0	0	0
  Gid:	0	0	0	0
  FDSize:	256
  Groups:
  NStgid:	1
  NSpid:	1
  NSpgid:	1
  NSsid:	1
  VmPeak:	  234192 kB           <-- here
  VmSize:	  169964 kB
  VmLck:	       0 kB
  VmPin:	       0 kB
  VmHWM:	   29528 kB
  VmRSS:	    6104 kB
  RssAnon:	    2756 kB
  RssFile:	    3348 kB
  RssShmem:	       0 kB
  VmData:	   19776 kB
  VmStk:	    1036 kB
  VmExe:	     784 kB
  VmLib:	    9532 kB
  VmPTE:	     116 kB
  VmSwap:	    2400 kB
  HugetlbPages:	       0 kB
  CoreDumping:	0
  THP_enabled:	1
  Threads:	1                     <-- and here
  SigQ:	1/62808
  SigPnd:	0000000000000000
  ShdPnd:	0000000000000000
  SigBlk:	7be3c0fe28014a03
  SigIgn:	0000000000001000

And this is for kernel thread:

  $ head -20 /proc/2/status
  Name:	kthreadd
  Umask:	0000
  State:	S (sleeping)
  Tgid:	2
  Ngid:	0
  Pid:	2
  PPid:	0
  TracerPid:	0
  Uid:	0	0	0	0
  Gid:	0	0	0	0
  FDSize:	64
  Groups:
  NStgid:	2
  NSpid:	2
  NSpgid:	0
  NSsid:	0
  Threads:	1                     <-- here
  SigQ:	1/62808
  SigPnd:	0000000000000000
  ShdPnd:	0000000000000000
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210202090118.2008551-3-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>