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authorIngo Molnar <mingo@kernel.org>2019-06-17 20:48:14 +0200
committerIngo Molnar <mingo@kernel.org>2019-06-17 20:48:14 +0200
commit3ce5aceb5dee298b082adfa2baa0df5a447c1b0b (patch)
treee5d3bcd206d4adc2251d0109d546cc7cc70e8d72 /tools
parentd0e1a507bdc761a14906f03399d933ea639a1756 (diff)
parent04c41bcb862bbec1fb225243ecf07a3219593f81 (diff)
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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>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/Documentation/db-export.txt41
-rw-r--r--tools/perf/Documentation/intel-pt.txt30
-rw-r--r--tools/perf/Documentation/perf-config.txt9
-rw-r--r--tools/perf/Documentation/perf-diff.txt14
-rw-r--r--tools/perf/Documentation/perf-record.txt11
-rw-r--r--tools/perf/Documentation/perf-report.txt9
-rw-r--r--tools/perf/Documentation/perf-script.txt14
-rw-r--r--tools/perf/Documentation/perf-stat.txt10
-rw-r--r--tools/perf/Documentation/perf.data-file-format.txt97
-rw-r--r--tools/perf/Makefile.config3
-rw-r--r--tools/perf/arch/arm/util/cs-etm.c313
-rw-r--r--tools/perf/builtin-record.c4
-rw-r--r--tools/perf/builtin-report.c8
-rw-r--r--tools/perf/builtin-script.c31
-rw-r--r--tools/perf/builtin-stat.c87
-rw-r--r--tools/perf/builtin-trace.c84
-rw-r--r--tools/perf/examples/bpf/augmented_raw_syscalls.c281
-rw-r--r--tools/perf/jvmti/libjvmti.c4
-rw-r--r--tools/perf/perf.h2
-rw-r--r--tools/perf/scripts/python/export-to-postgresql.py36
-rw-r--r--tools/perf/scripts/python/export-to-sqlite.py36
-rwxr-xr-xtools/perf/scripts/python/exported-sql-viewer.py294
-rw-r--r--tools/perf/tests/Build1
-rw-r--r--tools/perf/tests/builtin-test.c4
-rw-r--r--tools/perf/tests/parse-events.c27
-rw-r--r--tools/perf/tests/tests.h1
-rw-r--r--tools/perf/tests/time-utils-test.c251
-rw-r--r--tools/perf/util/annotate.c5
-rw-r--r--tools/perf/util/auxtrace.h34
-rw-r--r--tools/perf/util/config.c8
-rw-r--r--tools/perf/util/cpumap.c64
-rw-r--r--tools/perf/util/cpumap.h10
-rw-r--r--tools/perf/util/cputopo.c84
-rw-r--r--tools/perf/util/cputopo.h2
-rw-r--r--tools/perf/util/cs-etm-decoder/cs-etm-decoder.c268
-rw-r--r--tools/perf/util/cs-etm-decoder/cs-etm-decoder.h39
-rw-r--r--tools/perf/util/cs-etm.c1026
-rw-r--r--tools/perf/util/cs-etm.h94
-rw-r--r--tools/perf/util/env.c1
-rw-r--r--tools/perf/util/env.h3
-rw-r--r--tools/perf/util/event.h2
-rw-r--r--tools/perf/util/evsel.c16
-rw-r--r--tools/perf/util/header.c96
-rw-r--r--tools/perf/util/intel-pt-decoder/intel-pt-decoder.c329
-rw-r--r--tools/perf/util/intel-pt-decoder/intel-pt-decoder.h6
-rw-r--r--tools/perf/util/intel-pt.c354
-rw-r--r--tools/perf/util/perf_regs.h4
-rw-r--r--tools/perf/util/s390-cpumsf.c96
-rw-r--r--tools/perf/util/scripting-engines/trace-event-python.c8
-rw-r--r--tools/perf/util/smt.c8
-rw-r--r--tools/perf/util/stat-display.c29
-rw-r--r--tools/perf/util/stat-shadow.c1
-rw-r--r--tools/perf/util/stat.c1
-rw-r--r--tools/perf/util/stat.h1
-rw-r--r--tools/perf/util/symbol-elf.c3
-rw-r--r--tools/perf/util/thread-stack.c14
-rw-r--r--tools/perf/util/thread-stack.h4
-rw-r--r--tools/perf/util/time-utils.c132
58 files changed, 3581 insertions, 863 deletions
diff --git a/tools/perf/Documentation/db-export.txt b/tools/perf/Documentation/db-export.txt
new file mode 100644
index 000000000000..52ffccb02d55
--- /dev/null
+++ b/tools/perf/Documentation/db-export.txt
@@ -0,0 +1,41 @@
+Database Export
+===============
+
+perf tool's python scripting engine:
+
+ tools/perf/util/scripting-engines/trace-event-python.c
+
+supports scripts:
+
+ tools/perf/scripts/python/export-to-sqlite.py
+ tools/perf/scripts/python/export-to-postgresql.py
+
+which export data to a SQLite3 or PostgreSQL database.
+
+The export process provides records with unique sequential ids which allows the
+data to be imported directly to a database and provides the relationships
+between tables.
+
+Over time it is possible to continue to expand the export while maintaining
+backward and forward compatibility, by following some simple rules:
+
+1. Because of the nature of SQL, existing tables and columns can continue to be
+used so long as the names and meanings (and to some extent data types) remain
+the same.
+
+2. New tables and columns can be added, without affecting existing SQL queries,
+so long as the new names are unique.
+
+3. Scripts that use a database (e.g. exported-sql-viewer.py) can maintain
+backward compatibility by testing for the presence of new tables and columns
+before using them. e.g. function IsSelectable() in exported-sql-viewer.py
+
+4. The export scripts themselves maintain forward compatibility (i.e. an existing
+script will continue to work with new versions of perf) by accepting a variable
+number of arguments (e.g. def call_return_table(*x)) i.e. perf can pass more
+arguments which old scripts will ignore.
+
+5. The scripting engine tests for the existence of script handler functions
+before calling them. The scripting engine can also test for the support of new
+or optional features by checking for the existence and value of script global
+variables.
diff --git a/tools/perf/Documentation/intel-pt.txt b/tools/perf/Documentation/intel-pt.txt
index 60d99e5e7921..50c5b60101bd 100644
--- a/tools/perf/Documentation/intel-pt.txt
+++ b/tools/perf/Documentation/intel-pt.txt
@@ -103,6 +103,36 @@ The flags are "bcrosyiABEx" which stand for branch, call, return, conditional,
system, asynchronous, interrupt, transaction abort, trace begin, trace end, and
in transaction, respectively.
+Another interesting field that is not printed by default is 'ipc' which can be
+displayed as follows:
+
+ perf script --itrace=be -F+ipc
+
+There are two ways that instructions-per-cycle (IPC) can be calculated depending
+on the recording.
+
+If the 'cyc' config term (see config terms section below) was used, then IPC is
+calculated using the cycle count from CYC packets, otherwise MTC packets are
+used - refer to the 'mtc' config term. When MTC is used, however, the values
+are less accurate because the timing is less accurate.
+
+Because Intel PT does not update the cycle count on every branch or instruction,
+the 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 for that event type. Note IPC for "branches"
+events is calculated separately from IPC for "instructions" events.
+
+Also note that the IPC instruction count may or may not include the current
+instruction. If the cycle count is associated with an asynchronous branch
+(e.g. page fault or interrupt), then the instruction count does not include the
+current instruction, otherwise it does. That is consistent with whether or not
+that instruction has retired when the cycle count is updated.
+
+Another note, in the case of "branches" events, non-taken branches are not
+presently sampled, so IPC values for them do not appear e.g. a CYC packet with a
+TNT packet that starts with a non-taken branch. To see every possible IPC
+value, "instructions" events can be used e.g. --itrace=i0ns
+
While it is possible to create scripts to analyze the data, an alternative
approach is available to export the data to a sqlite or postgresql database.
Refer to script export-to-sqlite.py or export-to-postgresql.py for more details,
diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index 462b3cde0675..e4aa268d2e38 100644
--- a/tools/perf/Documentation/perf-config.txt
+++ b/tools/perf/Documentation/perf-config.txt
@@ -564,9 +564,12 @@ llvm.*::
llvm.clang-bpf-cmd-template::
Cmdline template. Below lines show its default value. Environment
variable is used to pass options.
- "$CLANG_EXEC -D__KERNEL__ $CLANG_OPTIONS $KERNEL_INC_OPTIONS \
- -Wno-unused-value -Wno-pointer-sign -working-directory \
- $WORKING_DIR -c $CLANG_SOURCE -target bpf -O2 -o -"
+ "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\
+ "-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE " \
+ "$CLANG_OPTIONS $PERF_BPF_INC_OPTIONS $KERNEL_INC_OPTIONS " \
+ "-Wno-unused-value -Wno-pointer-sign " \
+ "-working-directory $WORKING_DIR " \
+ "-c \"$CLANG_SOURCE\" -target bpf $CLANG_EMIT_LLVM -O2 -o - $LLVM_OPTIONS_PIPE"
llvm.clang-opt::
Options passed to clang.
diff --git a/tools/perf/Documentation/perf-diff.txt b/tools/perf/Documentation/perf-diff.txt
index da7809b15cc9..facd91e4e945 100644
--- a/tools/perf/Documentation/perf-diff.txt
+++ b/tools/perf/Documentation/perf-diff.txt
@@ -142,12 +142,14 @@ OPTIONS
perf diff --time 0%-10%,30%-40%
It also supports analyzing samples within a given time window
- <start>,<stop>. Times have the format seconds.microseconds. If 'start'
- is not given (i.e., time string is ',x.y') then analysis starts at
- the beginning of the file. If stop time is not given (i.e, time
- string is 'x.y,') then analysis goes to the end of the file. Time string is
- 'a1.b1,c1.d1:a2.b2,c2.d2'. Use ':' to separate timestamps for different
- perf.data files.
+ <start>,<stop>. Times have the format seconds.nanoseconds. If 'start'
+ is not given (i.e. time string is ',x.y') then analysis starts at
+ the beginning of the file. If stop time is not given (i.e. time
+ string is 'x.y,') then analysis goes to the end of the file.
+ Multiple ranges can be separated by spaces, which requires the argument
+ to be quoted e.g. --time "1234.567,1234.789 1235,"
+ Time string is'a1.b1,c1.d1:a2.b2,c2.d2'. Use ':' to separate timestamps
+ for different perf.data files.
For example, we get the timestamp information from 'perf script'.
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index de269430720a..15e0fa87241b 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -490,6 +490,17 @@ Configure all used events to run in kernel space.
--all-user::
Configure all used events to run in user space.
+--kernel-callchains::
+Collect callchains only from kernel space. I.e. this option sets
+perf_event_attr.exclude_callchain_user to 1.
+
+--user-callchains::
+Collect callchains only from user space. I.e. this option sets
+perf_event_attr.exclude_callchain_kernel to 1.
+
+Don't use both --kernel-callchains and --user-callchains at the same time or no
+callchains will be collected.
+
--timestamp-filename
Append timestamp to output file name.
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index f441baa794ce..8c4372819e11 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -412,12 +412,13 @@ OPTIONS
--time::
Only analyze samples within given time window: <start>,<stop>. Times
- have the format seconds.microseconds. If start is not given (i.e., time
+ have the format seconds.nanoseconds. If start is not given (i.e. time
string is ',x.y') then analysis starts at the beginning of the file. If
- stop time is not given (i.e, time string is 'x.y,') then analysis goes
- to end of file.
+ stop time is not given (i.e. time string is 'x.y,') then analysis goes
+ to end of file. Multiple ranges can be separated by spaces, which
+ requires the argument to be quoted e.g. --time "1234.567,1234.789 1235,"
- Also support time percent with multiple time range. Time string is
+ Also support time percent with multiple time ranges. Time string is
'a%/n,b%/m,...' or 'a%-b%,c%-%d,...'.
For example:
diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
index af8282782911..d4e2e18a5881 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -117,7 +117,7 @@ OPTIONS
Comma separated list of fields to print. Options are:
comm, tid, pid, time, cpu, event, trace, ip, sym, dso, addr, symoff,
srcline, period, iregs, uregs, brstack, brstacksym, flags, bpf-output, brstackinsn,
- brstackoff, callindent, insn, insnlen, synth, phys_addr, metric, misc, srccode.
+ brstackoff, callindent, insn, insnlen, synth, phys_addr, metric, misc, srccode, ipc.
Field list can be prepended with the type, trace, sw or hw,
to indicate to which event type the field list applies.
e.g., -F sw:comm,tid,time,ip,sym and -F trace:time,cpu,trace
@@ -203,6 +203,9 @@ OPTIONS
The synth field is used by synthesized events which may be created when
Instruction Trace decoding.
+ The ipc (instructions per cycle) field is synthesized and may have a value when
+ Instruction Trace decoding.
+
Finally, a user may not set fields to none for all event types.
i.e., -F "" is not allowed.
@@ -358,12 +361,13 @@ include::itrace.txt[]
--time::
Only analyze samples within given time window: <start>,<stop>. Times
- have the format seconds.microseconds. If start is not given (i.e., time
+ have the format seconds.nanoseconds. If start is not given (i.e. time
string is ',x.y') then analysis starts at the beginning of the file. If
- stop time is not given (i.e, time string is 'x.y,') then analysis goes
- to end of file.
+ stop time is not given (i.e. time string is 'x.y,') then analysis goes
+ to end of file. Multiple ranges can be separated by spaces, which
+ requires the argument to be quoted e.g. --time "1234.567,1234.789 1235,"
- Also support time percent with multipe time range. Time string is
+ Also support time percent with multiple time ranges. Time string is
'a%/n,b%/m,...' or 'a%-b%,c%-%d,...'.
For example:
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 1e312c2672e4..930c51c01201 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -200,6 +200,13 @@ use --per-socket in addition to -a. (system-wide). The output includes the
socket number and the number of online processors on that socket. This is
useful to gauge the amount of aggregation.
+--per-die::
+Aggregate counts per processor die for system-wide mode measurements. This
+is a useful mode to detect imbalance between dies. To enable this mode,
+use --per-die in addition to -a. (system-wide). The output includes the
+die number and the number of online processors on that die. This is
+useful to gauge the amount of aggregation.
+
--per-core::
Aggregate counts per physical processor for system-wide mode measurements. This
is a useful mode to detect imbalance between physical cores. To enable this mode,
@@ -239,6 +246,9 @@ Input file name.
--per-socket::
Aggregate counts per processor socket for system-wide mode measurements.
+--per-die::
+Aggregate counts per processor die for system-wide mode measurements.
+
--per-core::
Aggregate counts per physical processor for system-wide mode measurements.
diff --git a/tools/perf/Documentation/perf.data-file-format.txt b/tools/perf/Documentation/perf.data-file-format.txt
index 6967e9b02be5..5f54feb19977 100644
--- a/tools/perf/Documentation/perf.data-file-format.txt
+++ b/tools/perf/Documentation/perf.data-file-format.txt
@@ -151,25 +151,45 @@ struct {
HEADER_CPU_TOPOLOGY = 13,
-String lists defining the core and CPU threads topology.
-The string lists are followed by a variable length array
-which contains core_id and socket_id of each cpu.
-The number of entries can be determined by the size of the
-section minus the sizes of both string lists.
-
struct {
+ /*
+ * First revision of HEADER_CPU_TOPOLOGY
+ *
+ * See 'struct perf_header_string_list' definition earlier
+ * in this file.
+ */
+
struct perf_header_string_list cores; /* Variable length */
struct perf_header_string_list threads; /* Variable length */
+
+ /*
+ * Second revision of HEADER_CPU_TOPOLOGY, older tools
+ * will not consider what comes next
+ */
+
struct {
uint32_t core_id;
uint32_t socket_id;
} cpus[nr]; /* Variable length records */
+ /* 'nr' comes from previously processed HEADER_NRCPUS's nr_cpu_avail */
+
+ /*
+ * Third revision of HEADER_CPU_TOPOLOGY, older tools
+ * will not consider what comes next
+ */
+
+ struct perf_header_string_list dies; /* Variable length */
+ uint32_t die_id[nr_cpus_avail]; /* from previously processed HEADER_NR_CPUS, VLA */
};
Example:
- sibling cores : 0-3
+ sibling sockets : 0-8
+ sibling dies : 0-3
+ sibling dies : 4-7
sibling threads : 0-1
sibling threads : 2-3
+ sibling threads : 4-5
+ sibling threads : 6-7
HEADER_NUMA_TOPOLOGY = 14,
@@ -272,6 +292,69 @@ struct {
Two uint64_t for the time of first sample and the time of last sample.
+ HEADER_SAMPLE_TOPOLOGY = 22,
+
+Physical memory map and its node assignments.
+
+The format of data in MEM_TOPOLOGY is as follows:
+
+ 0 - version | for future changes
+ 8 - block_size_bytes | /sys/devices/system/memory/block_size_bytes
+ 16 - count | number of nodes
+
+For each node we store map of physical indexes:
+
+ 32 - node id | node index
+ 40 - size | size of bitmap
+ 48 - bitmap | bitmap of memory indexes that belongs to node
+ | /sys/devices/system/node/node<NODE>/memory<INDEX>
+
+The MEM_TOPOLOGY can be displayed with following command:
+
+$ perf report --header-only -I
+...
+# memory nodes (nr 1, block size 0x8000000):
+# 0 [7G]: 0-23,32-69
+
+ HEADER_CLOCKID = 23,
+
+One uint64_t for the clockid frequency, specified, for instance, via 'perf
+record -k' (see clock_gettime()), to enable timestamps derived metrics
+conversion into wall clock time on the reporting stage.
+
+ HEADER_DIR_FORMAT = 24,
+
+The data files layout is described by HEADER_DIR_FORMAT feature. Currently it
+holds only version number (1):
+
+ uint64_t version;
+
+The current version holds only version value (1) means that data files:
+
+- Follow the 'data.*' name format.
+
+- Contain raw events data in standard perf format as read from kernel (and need
+ to be sorted)
+
+Future versions are expected to describe different data files layout according
+to special needs.
+
+ HEADER_BPF_PROG_INFO = 25,
+
+struct bpf_prog_info_linear, which contains detailed informatio