diff options
Diffstat (limited to 'tools/perf/Documentation')
| -rw-r--r-- | tools/perf/Documentation/build-xed.txt | 19 | ||||
| -rw-r--r-- | tools/perf/Documentation/intel-pt.txt | 2 | ||||
| -rw-r--r-- | tools/perf/Documentation/itrace.txt | 7 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-bench.txt | 10 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-c2c.txt | 16 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-config.txt | 69 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-list.txt | 3 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-mem.txt | 2 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-record.txt | 24 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-report.txt | 10 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-script.txt | 26 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-stat.txt | 4 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-top.txt | 13 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf-trace.txt | 81 | ||||
| -rw-r--r-- | tools/perf/Documentation/perf.data-file-format.txt | 11 |
15 files changed, 276 insertions, 21 deletions
diff --git a/tools/perf/Documentation/build-xed.txt b/tools/perf/Documentation/build-xed.txt new file mode 100644 index 000000000000..6222c1e7231f --- /dev/null +++ b/tools/perf/Documentation/build-xed.txt @@ -0,0 +1,19 @@ + +For --xed the xed tool is needed. Here is how to install it: + + $ git clone https://github.com/intelxed/mbuild.git mbuild + $ git clone https://github.com/intelxed/xed + $ cd xed + $ ./mfile.py --share + $ ./mfile.py examples + $ sudo ./mfile.py --prefix=/usr/local install + $ sudo ldconfig + $ sudo cp obj/examples/xed /usr/local/bin + +Basic xed testing: + + $ xed | head -3 + ERROR: required argument(s) were missing + Copyright (C) 2017, Intel Corporation. All rights reserved. + XED version: [v10.0-328-g7d62c8c49b7b] + $ diff --git a/tools/perf/Documentation/intel-pt.txt b/tools/perf/Documentation/intel-pt.txt index 76971d2e4164..115eaacc455f 100644 --- a/tools/perf/Documentation/intel-pt.txt +++ b/tools/perf/Documentation/intel-pt.txt @@ -106,7 +106,7 @@ in transaction, respectively. 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, -and to script call-graph-from-sql.py for an example of using the database. +and to script exported-sql-viewer.py for an example of using the database. There is also script intel-pt-events.py which provides an example of how to unpack the raw data for power events and PTWRITE. diff --git a/tools/perf/Documentation/itrace.txt b/tools/perf/Documentation/itrace.txt index a3abe04c779d..c2182cbabde3 100644 --- a/tools/perf/Documentation/itrace.txt +++ b/tools/perf/Documentation/itrace.txt @@ -11,10 +11,11 @@ l synthesize last branch entries (use with i or x) s skip initial number of events - The default is all events i.e. the same as --itrace=ibxwpe + The default is all events i.e. the same as --itrace=ibxwpe, + except for perf script where it is --itrace=ce - In addition, the period (default 100000) for instructions events - can be specified in units of: + In addition, the period (default 100000, except for perf script where it is 1) + for instructions events can be specified in units of: i instructions t ticks diff --git a/tools/perf/Documentation/perf-bench.txt b/tools/perf/Documentation/perf-bench.txt index 34750fc32714..0921a3c67381 100644 --- a/tools/perf/Documentation/perf-bench.txt +++ b/tools/perf/Documentation/perf-bench.txt @@ -58,6 +58,9 @@ SUBSYSTEM 'futex':: Futex stressing benchmarks. +'epoll':: + Eventpoll (epoll) stressing benchmarks. + 'all':: All benchmark subsystems. @@ -203,6 +206,13 @@ Suite for evaluating requeue calls. *lock-pi*:: Suite for evaluating futex lock_pi calls. +SUITES FOR 'epoll' +~~~~~~~~~~~~~~~~~~ +*wait*:: +Suite for evaluating concurrent epoll_wait calls. + +*ctl*:: +Suite for evaluating multiple epoll_ctl calls. SEE ALSO -------- diff --git a/tools/perf/Documentation/perf-c2c.txt b/tools/perf/Documentation/perf-c2c.txt index 095aebdc5bb7..e6150f21267d 100644 --- a/tools/perf/Documentation/perf-c2c.txt +++ b/tools/perf/Documentation/perf-c2c.txt @@ -19,8 +19,11 @@ C2C stands for Cache To Cache. The perf c2c tool provides means for Shared Data C2C/HITM analysis. It allows you to track down the cacheline contentions. -The tool is based on x86's load latency and precise store facility events -provided by Intel CPUs. These events provide: +On x86, the tool is based on load latency and precise store facility events +provided by Intel CPUs. On PowerPC, the tool uses random instruction sampling +with thresholding feature. + +These events provide: - memory address of the access - type of the access (load and store details) - latency (in cycles) of the load access @@ -46,7 +49,7 @@ RECORD OPTIONS -l:: --ldlat:: - Configure mem-loads latency. + Configure mem-loads latency. (x86 only) -k:: --all-kernel:: @@ -119,11 +122,16 @@ Following perf record options are configured by default: -W,-d,--phys-data,--sample-cpu Unless specified otherwise with '-e' option, following events are monitored by -default: +default on x86: cpu/mem-loads,ldlat=30/P cpu/mem-stores/P +and following on PowerPC: + + cpu/mem-loads/ + cpu/mem-stores/ + User can pass any 'perf record' option behind '--' mark, like (to enable callchains and system wide monitoring): diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt index 32f4a898e3f2..86f3dcc15f83 100644 --- a/tools/perf/Documentation/perf-config.txt +++ b/tools/perf/Documentation/perf-config.txt @@ -120,6 +120,10 @@ Given a $HOME/.perfconfig like this: children = true group = true + [llvm] + dump-obj = true + clang-opt = -g + You can hide source code of annotate feature setting the config to false with % perf config annotate.hide_src_code=true @@ -199,6 +203,12 @@ colors.*:: Colors for headers in the output of a sub-commands (top, report). Default values are 'white', 'blue'. +core.*:: + core.proc-map-timeout:: + Sets a timeout (in milliseconds) for parsing /proc/<pid>/maps files. + Can be overridden by the --proc-map-timeout option on supported + subcommands. The default timeout is 500ms. + tui.*, gtk.*:: Subcommands that can be configured here are 'top', 'report' and 'annotate'. These values are booleans, for example: @@ -515,6 +525,65 @@ diff.*:: Possible values are 'delta', 'delta-abs', 'ratio' and 'wdiff'. Default is 'delta'. +trace.*:: + trace.add_events:: + Allows adding a set of events to add to the ones specified + by the user, or use as a default one if none was specified. + The initial use case is to add augmented_raw_syscalls.o to + activate the 'perf trace' logic that looks for syscall + pointer contents after the normal tracepoint payload. + + trace.args_alignment:: + Number of columns to align the argument list, default is 70, + use 40 for the strace default, zero to no alignment. + + trace.no_inherit:: + Do not follow children threads. + + trace.show_arg_names:: + Should syscall argument names be printed? If not then trace.show_zeros + will be set. + + trace.show_duration:: + Show syscall duration. + + trace.show_prefix:: + If set to 'yes' will show common string prefixes in tables. The default + is to remove the common prefix in things like "MAP_SHARED", showing just "SHARED". + + trace.show_timestamp:: + Show syscall start timestamp. + + trace.show_zeros:: + Do not suppress syscall arguments that are equal to zero. + +llvm.*:: + llvm.clang-path:: + Path to clang. If omit, search it from $PATH. + + llvm.clang-bpf-cmd-template:: + Cmdline template. Below lines show its default value. Environment + variable is used to pass options. + "$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 -" + + llvm.clang-opt:: + Options passed to clang. + + llvm.kbuild-dir:: + kbuild directory. If not set, use /lib/modules/`uname -r`/build. + If set to "" deliberately, skip kernel header auto-detector. + + llvm.kbuild-opts:: + Options passed to 'make' when detecting kernel header options. + + llvm.dump-obj:: + Enable perf dump BPF object files compiled by LLVM. + + llvm.opts:: + Options passed to llc. + SEE ALSO -------- linkperf:perf[1] diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt index 236b9b97dfdb..138fb6e94b3c 100644 --- a/tools/perf/Documentation/perf-list.txt +++ b/tools/perf/Documentation/perf-list.txt @@ -55,7 +55,6 @@ counted. The following modifiers exist: S - read sample value (PERF_SAMPLE_READ) D - pin the event to the PMU W - group is weak and will fallback to non-group if not schedulable, - only supported in 'perf stat' for now. The 'p' modifier can be used for specifying how precise the instruction address should be. The 'p' modifier can be specified multiple times: @@ -173,7 +172,7 @@ like cycles and instructions and some software events. Other PMUs and global measurements are normally root only. Some event qualifiers, such as "any", are also root only. -This can be overriden by setting the kernel.perf_event_paranoid +This can be overridden by setting the kernel.perf_event_paranoid sysctl to -1, which allows non root to use these events. For accessing trace point events perf needs to have read access to diff --git a/tools/perf/Documentation/perf-mem.txt b/tools/perf/Documentation/perf-mem.txt index f8d2167cf3e7..199ea0f0a6c0 100644 --- a/tools/perf/Documentation/perf-mem.txt +++ b/tools/perf/Documentation/perf-mem.txt @@ -82,7 +82,7 @@ RECORD OPTIONS Be more verbose (show counter open errors, etc) --ldlat <n>:: - Specify desired latency for loads event. + Specify desired latency for loads event. (x86 only) In addition, for report all perf report options are valid, and for record all perf record options. diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 246dee081efd..8f0c2be34848 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -88,6 +88,20 @@ OPTIONS If you want to profile write accesses in [0x1000~1008), just set 'mem:0x1000/8:w'. + - a BPF source file (ending in .c) or a precompiled object file (ending + in .o) selects one or more BPF events. + The BPF program can attach to various perf events based on the ELF section + names. + + When processing a '.c' file, perf searches an installed LLVM to compile it + into an object file first. Optional clang options can be passed via the + '--clang-opt' command line option, e.g.: + + perf record --clang-opt "-DLINUX_VERSION_CODE=0x50000" \ + -e tests/bpf-script-example.c + + Note: '--clang-opt' must be placed before '--event/-e'. + - a group of events surrounded by a pair of brace ("{event1,event2,...}"). Each event is separated by commas and the group should be quoted to prevent the shell interpretation. You also need to use --group on @@ -435,6 +449,16 @@ Specify vmlinux path which has debuginfo. --buildid-all:: Record build-id of all DSOs regardless whether it's actually hit or not. +--aio[=n]:: +Use <n> control blocks in asynchronous (Posix AIO) trace writing mode (default: 1, max: 4). +Asynchronous mode is supported only when linking Perf tool with libc library +providing implementation for Posix AIO API. + +--affinity=mode:: +Set affinity mask of trace reading thread according to the policy defined by 'mode' value: + node - thread affinity mask is set to NUMA node cpu mask of the processed mmap buffer + cpu - thread affinity mask is set to cpu of the processed mmap buffer + --all-kernel:: Configure all used events to run in kernel space. diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt index 474a4941f65d..1a27bfe05039 100644 --- a/tools/perf/Documentation/perf-report.txt +++ b/tools/perf/Documentation/perf-report.txt @@ -126,6 +126,14 @@ OPTIONS And default sort keys are changed to comm, dso_from, symbol_from, dso_to and symbol_to, see '--branch-stack'. + When the sort key symbol is specified, columns "IPC" and "IPC Coverage" + are enabled automatically. Column "IPC" reports the average IPC per function + and column "IPC coverage" reports the percentage of instructions with + sampled IPC in this function. IPC means Instruction Per Cycle. If it's low, + it indicates there may be a performance bottleneck when the function is + executed, such as a memory access bottleneck. If a function has high overhead + and low IPC, it's worth further analyzing it to optimize its performance. + If the --mem-mode option is used, the following sort keys are also available (incompatible with --branch-stack): symbol_daddr, dso_daddr, locked, tlb, mem, snoop, dcacheline. @@ -244,7 +252,7 @@ OPTIONS Usually more convenient to use --branch-history for this. value can be: - - percent: diplay overhead percent (default) + - percent: display overhead percent (default) - period: display event period - count: display event count diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt index afdafe2110a1..2e19fd7ffe35 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. + brstackoff, callindent, insn, insnlen, synth, phys_addr, metric, misc, srccode. 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 @@ -159,6 +159,12 @@ OPTIONS the override, and the result of the above is that only S/W and H/W events are displayed with the given fields. + It's possible tp add/remove fields only for specific event type: + + -Fsw:-cpu,-period + + removes cpu and period from software events. + For the 'wildcard' option if a user selected field is invalid for an event type, a message is displayed to the user that the option is ignored for that type. For example: @@ -383,6 +389,24 @@ include::itrace.txt[] will be printed. Each entry has function name and file/line. Enabled by default, disable with --no-inline. +--insn-trace:: + Show instruction stream for intel_pt traces. Combine with --xed to + show disassembly. + +--xed:: + Run xed disassembler on output. Requires installing the xed disassembler. + +--call-trace:: + Show call stream for intel_pt traces. The CPUs are interleaved, but + can be filtered with -C. + +--call-ret-trace:: + Show call and return stream for intel_pt traces. + +--graph-function:: + For itrace only show specified functions and their callees for + itrace. Multiple functions can be separated by comma. + SEE ALSO -------- linkperf:perf-record[1], linkperf:perf-script-perl[1], diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt index b10a90b6a718..4bc2085e5197 100644 --- a/tools/perf/Documentation/perf-stat.txt +++ b/tools/perf/Documentation/perf-stat.txt @@ -50,7 +50,7 @@ report:: /sys/bus/event_source/devices/<pmu>/format/* Note that the last two syntaxes support prefix and glob matching in - the PMU name to simplify creation of events accross multiple instances + the PMU name to simplify creation of events across multiple instances of the same type of PMU in large systems (e.g. memory controller PMUs). Multiple PMU instances are typical for uncore PMUs, so the prefix 'uncore_' is also ignored when performing this match. @@ -277,7 +277,7 @@ echo 0 > /proc/sys/kernel/nmi_watchdog for best results. Otherwise the bottlenecks may be inconsistent on workload with changing phases. -This enables --metric-only, unless overriden with --no-metric-only. +This enables --metric-only, unless overridden with --no-metric-only. To interpret the results it is usually needed to know on which CPUs the workload runs on. If needed the CPUs can be forced using diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt index 114fda12aa49..44d89fb9c788 100644 --- a/tools/perf/Documentation/perf-top.txt +++ b/tools/perf/Documentation/perf-top.txt @@ -70,6 +70,9 @@ Default is to monitor all CPUS. --ignore-vmlinux:: Ignore vmlinux files. +--kallsyms=<file>:: + kallsyms pathname + -m <pages>:: --mmap-pages=<pages>:: Number of mmap data pages (must be a power of two) or size @@ -242,6 +245,16 @@ Default is to monitor all CPUS. --hierarchy:: Enable hierarchy output. +--overwrite:: + Enable this to use just the most recent records, which helps in high core count + machines such as Knights Landing/Mill, but right now is disabled by default as + the pausing used in this technique is leading to loss of metadata events such + as PERF_RECORD_MMAP which makes 'perf top' unable to resolve samples, leading + to lots of unknown samples appearing on the UI. Enable this if you are in such + machines and profiling a workload that doesn't creates short lived threads and/or + doesn't uses many executable mmap operations. Work is being planed to solve + this situation, till then, this will remain disabled by default. + --force:: Don't do ownership validation. diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt index 115db9e06ecd..fc6e43262c41 100644 --- a/tools/perf/Documentation/perf-trace.txt +++ b/tools/perf/Documentation/perf-trace.txt @@ -171,6 +171,11 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs. --kernel-syscall-graph:: Show the kernel callchains on the syscall exit path. +--max-events=N:: + Stop after processing N events. Note that strace-like events are considered + only at exit time or when a syscall is interrupted, i.e. in those cases this + option is equivalent to the number of lines printed. + --max-stack:: Set the stack depth limit when parsing the callchain, anything beyond the specified depth will be ignored. Note that at this point @@ -200,6 +205,20 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs. because the file may be huge. A time out is needed in such cases. This option sets the time out limit. The default value is 500 ms. +--sort-events:: + Do sorting on batches of events, use when noticing out of order events that + may happen, for instance, when a thread gets migrated to a different CPU + while processing a syscall. + +--map-dump:: + Dump BPF maps setup by events passed via -e, for instance the augmented_raw_syscalls + living in tools/perf/examples/bpf/augmented_raw_syscalls.c. For now this + dumps just boolean map values and integer keys, in time this will print in hex + by default and use BTF when available, as well as use functions to do pretty + printing using the existing 'perf trace' syscall arg beautifiers to map integer + arguments to strings (pid to comm, syscall id to syscall name, etc). + + PAGEFAULTS ---------- @@ -238,6 +257,68 @@ Trace syscalls, major and minor pagefaults: As you can see, there was major pagefault in python process, from CRYPTO_push_info_ routine which faulted somewhere in libcrypto.so. +Trace the first 4 open, openat or open_by_handle_at syscalls (in the future more syscalls may match here): + + $ perf trace -e open* --max-events 4 + [root@jouet perf]# trace -e open* --max-events 4 + 2272.992 ( 0.037 ms): gnome-shell/1370 openat(dfd: CWD, filename: /proc/self/stat) = 31 + 2277.481 ( 0.139 ms): gnome-shell/3039 openat(dfd: CWD, filename: /proc/self/stat) = 65 + 3026.398 ( 0.076 ms): gnome-shell/3039 openat(dfd: CWD, filename: /proc/self/stat) = 65 + 4294.665 ( 0.015 ms): sed/15879 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC) = 3 + $ + +Trace the first minor page fault when running a workload: + + # perf trace -F min --max-stack=7 --max-events 1 sleep 1 + 0.000 ( 0.000 ms): sleep/18006 minfault [__clear_user+0x1a] => 0x5626efa56080 (?k) + __clear_user ([kernel.kallsyms]) + load_elf_binary ([kernel.kallsyms]) + search_binary_handler ([kernel.kallsyms]) + __do_execve_file.isra.33 ([kernel.kallsyms]) + __x64_sys_execve ([kernel.kallsyms]) + do_syscall_64 ([kernel.kallsyms]) + entry_SYSCALL_64 ([kernel.kallsyms]) + # + +Trace the next min page page fault to take place on the first CPU: + + # perf trace -F min --call-graph=dwarf --max-events 1 --cpu 0 + 0.000 ( 0.000 ms): Web Content/17136 minfault [js::gc::Chunk::fetchNextDecommittedArena+0x4b] => 0x7fbe6181b000 (?.) + js::gc::FreeSpan::initAsEmpty (inlined) + js::gc::Arena::setAsNotAllocated (inlined) + js::gc::Chunk::fetchNextDecommittedArena (/usr/lib64/firefox/libxul.so) + js::gc::Chunk::allocateArena (/usr/lib64/firefox/libxul.so) + js::gc::GCRuntime::allocateArena (/usr/lib64/firefox/libxul.so) + js::gc::ArenaLists::allocateFromArena (/usr/lib64/firefox/libxul.so) + js::gc::GCRuntime::tryNewTenuredThing<JSString, (js::AllowGC)1> (inlined) + js::AllocateString<JSString, (js::AllowGC)1> (/usr/lib64/firefox/libxul.so) + js::Allocate<JSThinInlineString, (js::AllowGC)1> (inlined) + JSThinInlineString::new_<(js::AllowGC)1> (inlined) + AllocateInlineString<(js::AllowGC)1, unsigned char> (inlined) + js::ConcatStrings<(js::AllowGC)1> (/usr/lib64/firefox/libxul.so) + [0x18b26e6bc2bd] (/tmp/perf-17136.map) + # + +Trace the next two sched:sched_switch events, four block:*_plug events, the +next block:*_unplug and the next three net:*dev_queue events, this last one +with a backtrace of at most 16 entries, system wide: + + # perf trace -e sched:*switch/nr=2/,block:*_plug/nr=4/,block:*_unplug/nr=1/,net:*dev_queue/nr=3,max-stack=16/ + 0.000 :0/0 sched:sched_switch:swapper/2:0 [120] S ==> rcu_sched:10 [120] + 0.015 rcu_sched/10 sched:sched_switch:rcu_sched:10 [120] R ==> swapper/2:0 [120] + 254.198 irq/50-iwlwifi/680 net:net_dev_queue:dev=wlp3s0 skbaddr=0xffff93498051f600 len=66 + __dev_queue_xmit ([kernel.kallsyms]) + 273.977 :0/0 net:net_dev_queue:dev=wlp3s0 skbaddr=0xffff93498051f600 len=78 + __dev_queue_xmit ([kernel.kallsyms]) + 274.007 :0/0 net:net_dev_queue:dev=wlp3s0 skbaddr=0xffff93498051ff00 len=78 + __dev_queue_xmit ([kernel.kallsyms]) + 2930.140 kworker/u16:58/2722 block:block_plug:[kworker/u16:58] + 2930.162 kworker/u16:58/2722 block:block_unplug:[kworker/u16:58] 1 + 4466.094 jbd2/dm-2-8/748 block:block_plug:[jbd2/dm-2-8] + 8050.123 kworker/u16:30/2694 block:block_plug:[kworker/u16:30] + 8050.271 kworker/u16:30/2694 block:block_plug:[kworker/u16:30] + # + SEE ALSO -------- linkperf:perf-record[1], linkperf:perf-script[1] diff --git a/tools/perf/Documentation/perf.data-file-format.txt b/tools/perf/Documentation/perf.data-file-format.txt index dfb218feaad9..593ef49b273c 100644 --- a/tools/perf/Documentation/perf.data-file-format.txt +++ b/tools/perf/Documentation/perf.data-file-format.txt @@ -43,11 +43,10 @@ struct perf_file_section { Flags section: -The header is followed by different optional headers, described by the bits set -in flags. Only headers for which the bit is set are included. Each header -consists of a perf_file_section located after the initial header. -The respective perf_file_section points to the data of the additional -header and defines its size. +For each of the optional features a perf_file_section it placed after the data +section if the feature bit is set in the perf_header flags bitset. The +respective perf_file_section points to the data of the additional header and +defines its size. Some headers consist of strings, which are defined like this: @@ -131,7 +130,7 @@ An uint64_t with the total memory in bytes. HEADER_CMDLINE = 11, -A perf_header_string with the perf command line used to collect the data. +A perf_header_string_list with the perf arg-vector used to collect the data. HEADER_EVENT_DESC = 12, |
