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       perf-config - Get and set variables in a configuration file.


       perf config [<file-option>] [[=value] ...]
       perf config [<file-option>] -l | --list


       You can manage variables in a configuration file with this command.


       -l, --list
           Show current config variables, name and value, for all sections.

           For writing and reading options: write to user $HOME/.perfconfig file or read it.

           For writing and reading options: write to system-wide $(sysconfdir)/perfconfig or read


       The perf configuration file contains many variables to change various aspects of each of
       its tools, including output, disk usage, etc. The $HOME/.perfconfig file is used to store
       a per-user configuration. The file $(sysconfdir)/perfconfig can be used to store a
       system-wide default configuration.

       One an disable reading config files by setting the PERF_CONFIG environment variable to
       /dev/null, or provide an alternate config file by setting that variable.

       When reading or writing, the values are read from the system and user configuration files
       by default, and options --system and --user can be used to tell the command to read from
       or write to only that location.

       The file consist of sections. A section starts with its name surrounded by square brackets
       and continues till the next section begins. Each variable must be in a section, and have
       the form name = value, for example:

                   name1 = value1
                   name2 = value2

       Section names are case sensitive and can contain any characters except newline (double
       quote " and backslash have to be escaped as \" and \\, respectively). Section headers
       can’t span multiple lines.

       Given a $HOME/.perfconfig like this:

       # # This is the config file, and # a # and ; character indicates a comment #

                   # Color variables
                   top = red, default
                   medium = green, default
                   normal = lightgray, default
                   selected = white, lightgray
                   jump_arrows = blue, default
                   addr = magenta, default
                   root = white, blue

                   # Defaults if linked with libslang
                   report = on
                   annotate = on
                   top = on

                   # Default, disable using /dev/null
                   dir = ~/.debug

                   # Defaults
                   hide_src_code = false
                   use_offset = true
                   jump_arrows = true
                   show_nr_jumps = false

                   # Format can be man, info, web or html
                   format = man
                   autocorrect = 0

                   show-headers = true

                   # fp (framepointer), dwarf
                   record-mode = fp
                   print-type = graph
                   order = caller
                   sort-key = function

                   # Defaults
                   sort_order = comm,dso,symbol
                   percent-limit = 0
                   queue-size = 0
                   children = true
                   group = true
                   skip-empty = true

                   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

       If you want to add or modify several config items, you can do like

           % perf config kmem.default=slab

       To modify the sort order of report functionality in user config file(i.e. ~/.perfconfig),

           % perf config --user report.sort-order=srcline

       To change colors of selected line to other foreground and background colors in system
       config file (i.e. $(sysconf)/perfconfig), do

           % perf config --system colors.selected=yellow,green

       To query the record mode of call graph, do

           % perf config call-graph.record-mode

       If you want to know multiple config key/value pairs, you can do like

           % perf config report.queue-size call-graph.order report.children

       To query the config value of sort order of call graph in user config file (i.e.
       ~/.perfconfig), do

           % perf config --user call-graph.sort-order

       To query the config value of buildid directory in system config file (i.e.
       $(sysconf)/perfconfig), do

           % perf config --system buildid.dir

           The variables for customizing the colors used in the output for the report, top and
           annotate in the TUI. They should specify the foreground and background colors,
           separated by a comma, for example:

               medium = green, lightgray

               If you want to use the color configured for you terminal, just leave it
               as 'default', for example:

               medium = default, lightgray

               Available colors:
               red, yellow, green, cyan, gray, black, blue,
               white, default, magenta, lightgray
           top means a overhead percentage which is more than 5%. And values of this variable
           specify percentage colors. Basic key values are foreground-color red and
           background-color default.

           medium means a overhead percentage which has more than 0.5%. Default values are green
           and default.

           normal means the rest of overhead percentages except top, medium, selected. Default
           values are lightgray and default.

           This selects the colors for the current entry in a list of entries from sub-commands
           (top, report, annotate). Default values are black and lightgray.

           Colors for jump arrows on assembly code listings such as jns, jmp, jane, etc. Default
           values are blue, default.

           This selects colors for addresses from annotate. Default values are magenta, default.

           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

       tui., gtk.
           Subcommands that can be configured here are top, report and annotate. These values are
           booleans, for example:

                       top = true

               will make the TUI be the default for the 'top' subcommand. Those will be
               available if the required libs were detected at tool build time.

       buildid.*, buildid.dir
           Each executable and shared library in modern distributions comes with a content based
           identifier that, if available, will be inserted in a file header to, at
           analysis time find what is needed to do symbol resolution, code annotation, etc.

               The recording tools also stores a hard link or copy in a per-user
               directory, $HOME/.debug/, of binaries, shared libraries, /proc/kallsyms
               and /proc/kcore files to be used at analysis time.

               The buildid.dir variable can be used to either change this directory
               cache location, or to disable it altogether. If you want to disable it,
               set buildid.dir to /dev/null. The default is $HOME/.debug

           buildid-cache.debuginfod=URLs Specify debuginfod URLs to be used when retrieving
  binaries, it follows the same syntax as the DEBUGINFOD_URLS variable, like:


           These are in control of addresses, jump function, source code in lines of assembly
           code from a specific program.

                       Use this to change the default disassembler style to some other value
                       supported by binutils, such as "intel", see the '-M' option help in the
                       'objdump' man page.

           If a program which is analyzed has source code, this option lets annotate print a list
           of assembly code with the source code. For example, let’s see a part of a program.
           There’re four lines. If this option is true, they can be printed without source code
           from a program as below.

               │        push   %rbp
               │        mov    %rsp,%rbp
               │        sub    $0x10,%rsp
               │        mov    (%rdi),%rdx

               But if this option is 'false', source code of the part
               can be also printed as below. Default is 'false'.

               │      struct rb_node *rb_next(const struct rb_node *node)
               │      {
               │        push   %rbp
               │        mov    %rsp,%rbp
               │        sub    $0x10,%rsp
               │              struct rb_node *parent;
               │              if (RB_EMPTY_NODE(node))
               │        mov    (%rdi),%rdx
               │              return n;

               This option works with tui, stdio2 browsers.

           Basing on a first address of a loaded function, offset can be used. Instead of using
           original addresses of assembly code, addresses subtracted from a base address can be
           printed. Let’s illustrate an example. If a base address is 0XFFFFFFFF81624d50 as

               ffffffff81624d50 <load0>

               an address on assembly code has a specific absolute address as below

               ffffffff816250b8:│  mov    0x8(%r14),%rdi

               but if use_offset is 'true', an address subtracted from a base address is printed.
               Default is true. This option is only applied to TUI.

               368:│  mov    0x8(%r14),%rdi

               This option works with tui, stdio2 browsers.

           There can be jump instruction among assembly code. Depending on a boolean value of
           jump_arrows, arrows can be printed or not which represent where do the instruction
           jump into as below.

               │     ┌──jmp    1333
               │     │  xchg   %ax,%ax
               │1330:│  mov    %r15,%r10
               │1333:└─→cmp    %r15,%r14

               If jump_arrow is 'false', the arrows isn't printed as below.
               Default is 'false'.

               │      ↓ jmp    1333
               │        xchg   %ax,%ax
               │1330:   mov    %r15,%r10
               │1333:   cmp    %r15,%r14

               This option works with tui browser.

           When showing source code if this option is true, line numbers are printed as below.

               │1628         if (type & PERF_SAMPLE_IDENTIFIER) {
               │     ↓ jne    508
               │1628                 data->id = *array;
               │1629                 array++;
               │1630         }

               However if this option is 'false', they aren't printed as below.
               Default is 'false'.

               │             if (type & PERF_SAMPLE_IDENTIFIER) {
               │     ↓ jne    508
               │                     data->id = *array;
               │                     array++;
               │             }

               This option works with tui, stdio2 browsers.

           Let’s see a part of assembly code.

               │1382:   movb   $0x1,-0x270(%rbp)

               If use this, the number of branches jumping to that address can be printed as below.
               Default is 'false'.

               │1 1382:   movb   $0x1,-0x270(%rbp)

               This option works with tui, stdio2 browsers.

           To compare two records on an instruction base, with this option provided, display
           total number of samples that belong to a line in assembly code. If this option is
           true, total periods are printed instead of percent values as below.

               302 │      mov    %eax,%eax

               But if this option is 'false', percent values for overhead are printed i.e.
               Default is 'false'.

               99.93 │      mov    %eax,%eax

               This option works with tui, stdio2, stdio browsers.

           By default perf annotate shows percentage of samples. This option can be used to print
           absolute number of samples. Ex, when set as false:

                74.03 │      mov    %fs:0x28,%rax

               When set as true:

                    6 │      mov    %fs:0x28,%rax

               This option works with tui, stdio2, stdio browsers.

           Default is 1, meaning just jump targets will have offsets show right beside the
           instruction. When set to 2 call instructions will also have its offsets shown, 3 or
           higher will show offsets for all instructions.

               This option works with tui, stdio2 browsers.

           Demangle symbol names to human readable form. Default is true.

           Demangle kernel symbol names to human readable form. Default is true.

       hist.*, hist.percentage
           This option control the way to calculate overhead of filtered entries - that means the
           value of this option is effective only if there’s a filter (by comm, dso or symbol
           name). Suppose a following example:

               Overhead  Symbols
               ........  .......
                33.33%     foo
                33.33%     bar
                33.33%     baz

               This is an original overhead and we'll filter out the first 'foo'
               entry. The value of 'relative' would increase the overhead of 'bar'
               and 'baz' to 50.00% for each, while 'absolute' would show their
               current overhead (33.33%).

           This option controls display of column headers (like Overhead and Symbol) in report
           and top. If this option is false, they are hidden. This option is only applied to TUI.

           The following controls the handling of call-graphs (obtained via the -g/--call-graph

           The mode for user space can be fp (frame pointer), dwarf and lbr. The value dwarf is
           effective only if libunwind (or a recent version of libdw) is present on the system;
           the value lbr only works for certain cpus. The method for kernel space is controlled
           not by this option but by the kernel config (CONFIG_UNWINDER_*).

           The size of stack to dump in order to do post-unwinding. Default is 8192 (byte). When
           using dwarf into record-mode, the default size will be used if omitted.

           The print-types can be graph (graph absolute), fractal (graph relative), flat and
           folded. This option controls a way to show overhead for each callchain entry. Suppose
           a following example.

               Overhead  Symbols
               ........  .......
                 40.00%  foo
                            |          main

               This output is a 'fractal' format. The 'foo' came from 'bar' and 'baz' exactly
               half and half so 'fractal' shows 50.00% for each
               (meaning that it assumes 100% total overhead of 'foo').

               The 'graph' uses absolute overhead value of 'foo' as total so each of
               'bar' and 'baz' callchain will have 20.00% of overhead.
               If 'flat' is used, single column and linear exposure of call chains.
               'folded' mean call chains are displayed in a line, separated by semicolons.

           This option controls print order of callchains. The default is callee which means
           callee is printed at top and then followed by its caller and so on. The caller prints
           it in reverse order.

               If this option is not set and report.children or top.children is
               set to true (or the equivalent command line option is given),
               the default value of this option is changed to 'caller' for the
               execution of 'perf report' or 'perf top'. Other commands will
               still default to 'callee'.

           The callchains are merged if they contain same information. The sort-key option
           determines a way to compare the callchains. A value of sort-key can be function or
           address. The default is function.

           When there’re many callchains it’d print tons of lines. So perf omits small callchains
           under a certain overhead (threshold) and this option control the threshold. Default is
           0.5 (%). The overhead is calculated by value depends on call-graph.print-type.

           This is a maximum number of lines of callchain printed for a single histogram entry.
           Default is 0 which means no limitation.

       report.*, report.sort_order
           Allows changing the default sort order from "comm,dso,symbol" to some other default,
           for instance "sym,dso" may be more fitting for kernel developers.

           This one is mostly the same as call-graph.threshold but works for histogram entries.
           Entries having an overhead lower than this percentage will not be printed. Default is
           0. If percent-limit is 10, only entries which have more than 10% of overhead will be

           This option sets up the maximum allocation size of the internal event queue for
           ordering events. Default is 0, meaning no limit.

           Children means functions called from another function. If this option is true, perf
           report cumulates callchains of children and show (accumulated) total overhead as well
           as Self overhead. Please refer to the perf report manual. The default is true.
           This option is to show event group information together. Example output with this
           turned on, notice that there is one column per event in the group, ref-cycles and

               # group: {ref-cycles,cycles}
               # ========
               # Samples: 7K of event 'anon group { ref-cycles, cycles }'
               # Event count (approx.): 6876107743
               #         Overhead  Command      Shared Object               Symbol
               # ................  .......  .................  ...................
                   99.84%  99.76%  noploop  noploop            [.] main
                    0.07%   0.00%  noploop         [.] strcmp
                    0.03%   0.00%  noploop  [kernel.kallsyms]  [k] timerqueue_del

           This option can change default stat behavior with empty results. If it’s set true,
           perf report --stat will not show 0 stats.

       top.*, top.children
           Same as report.children. So if it is enabled, the output of top command will have
           Children overhead column as well as Self overhead column by default. The default is
           This is identical to call-graph.record-mode, except it is applicable only for top
           subcommand. This option ONLY setup the unwind method. To enable perf top to actually
           use it, the command line option -g must be specified.

       man.*, man.viewer
           This option can assign a tool to view manual pages when help subcommand was invoked.
           Supported tools are man, woman (with emacs client) and konqueror. Default is man.

               New man viewer tool can be also added using 'man.<tool>.cmd'
               or use different path using 'man.<tool>.path' config option.

       pager.*, pager.<subcommand>
           When the subcommand is run on stdio, determine whether it uses pager or not based on
           this value. Default is unspecified.

       kmem.*, kmem.default
           This option decides which allocator is to be analyzed if neither --slab nor --page
           option is used. Default is slab.

           This option can be cache, no-cache, skip or mmap.  cache is to post-process data and
           save/update the binaries into the build-id cache (in ~/.debug). This is the default.
           But if this option is no-cache, it will not update the build-id cache.  skip skips
           post-processing and does not update the cache.  mmap skips post-processing and reads
           build-ids from MMAP events.
           This is identical to call-graph.record-mode, except it is applicable only for record
           subcommand. This option ONLY setup the unwind method. To enable perf record to
           actually use it, the command line option -g must be specified.

           Use n control blocks in asynchronous (Posix AIO) trace writing mode (n default: 1,
           max: 4).

       diff.*, diff.order
           This option sets the number of columns to sort the result. The default is 0, which
           means sorting by baseline. Setting it to 1 will sort the result by delta (or other
           compute method selected).

           This options sets the method for computing the diff result. 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.

           Number of columns to align the argument list, default is 70, use 40 for the strace
           default, zero to no alignment.

           Do not follow children threads.

           Should syscall argument names be printed? If not then trace.show_zeros will be set.

           Show syscall duration.

           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".

           Show syscall start timestamp.

           Do not suppress syscall arguments that are equal to zero.

           Use "libtraceevent" to use that library to augment the tracepoint arguments,
           "libbeauty", the default, to use the same argument beautifiers used in the strace-like
           sys_enter+sys_exit lines.

       ftrace.*, ftrace.tracer
           Can be used to select the default tracer when neither -G nor -F option is not
           specified. Possible values are function and function_graph.

       llvm.*, llvm.clang-path
           Path to clang. If omit, search it from $PATH.

           Cmdline template. Below lines show its default value. Environment variable is used to
           pass options. "$CLANG_EXEC -DKERNEL -DNR_CPUS=$NR_CPUS "\
           $KERNEL_INC_OPTIONS " \ "-Wno-unused-value -Wno-pointer-sign " \ "-working-directory
           $WORKING_DIR " \ "-c \"$CLANG_SOURCE\" -target bpf $CLANG_EMIT_LLVM -O2 -o -

           Options passed to clang.

           kbuild directory. If not set, use /lib/modules/uname -r/build. If set to ""
           deliberately, skip kernel header auto-detector.

           Options passed to make when detecting kernel header options.

           Enable perf dump BPF object files compiled by LLVM.

           Options passed to llc.

       samples.*, samples.context
           Define how many ns worth of time to show around samples in perf report sample context

           Any option defines a script that is added to the scripts menu in the interactive perf
           browser and whose output is displayed. The name of the option is the name, the value
           is a script command line. The script gets the same options passed as a full perf
           script, in particular -i perfdata file, --cpu, --tid

       convert.*, convert.queue-size
           Limit the size of ordered_events queue, so we could control allocation size of perf
           data files without proper finished round events.

       stat.*, stat.big-num
           (boolean) Change the default for "--big-num". To make "--no-big-num" the default, set

       intel-pt.*, intel-pt.cache-divisor, intel-pt.mispred-all
           If set, Intel PT decoder will set the mispred flag on all branches.

           If set and non-zero, the maximum number of unconditional branches decoded without
           consuming any trace packets. If the maximum is exceeded there will be a "Never-ending
           loop" error. The default is 100000.

       auxtrace.*, auxtrace.dumpdir
           s390 only. The directory to save the auxiliary trace buffer can be changed using this
           option. Ex, auxtrace.dumpdir=/tmp. If the directory does not exist or has the wrong
           file type, the current directory is used.

       daemon.*, daemon.base
           Base path for daemon data. All sessions data are stored under this path.

       session-<NAME>.*, session-<NAME>.run
           Defines new record session for daemon. The value is record’s command line without the
           record keyword.