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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
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Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+perf-report(1)
+==============
+
+NAME
+----
+perf-report - Read perf.data (created by perf record) and display the profile
+
+SYNOPSIS
+--------
+[verse]
+'perf report' [-i <file> | --input=file]
+
+DESCRIPTION
+-----------
+This command displays the performance counter profile information recorded
+via perf record.
+
+OPTIONS
+-------
+-i::
+--input=::
+ Input file name. (default: perf.data unless stdin is a fifo)
+
+-v::
+--verbose::
+ Be more verbose. (show symbol address, etc)
+
+-q::
+--quiet::
+ Do not show any message. (Suppress -v)
+
+-n::
+--show-nr-samples::
+ Show the number of samples for each symbol
+
+--show-cpu-utilization::
+ Show sample percentage for different cpu modes.
+
+-T::
+--threads::
+ Show per-thread event counters. The input data file should be recorded
+ with -s option.
+-c::
+--comms=::
+ Only consider symbols in these comms. CSV that understands
+ file://filename entries. This option will affect the percentage of
+ the overhead column. See --percentage for more info.
+--pid=::
+ Only show events for given process ID (comma separated list).
+
+--tid=::
+ Only show events for given thread ID (comma separated list).
+-d::
+--dsos=::
+ Only consider symbols in these dsos. CSV that understands
+ file://filename entries. This option will affect the percentage of
+ the overhead column. See --percentage for more info.
+-S::
+--symbols=::
+ Only consider these symbols. CSV that understands
+ file://filename entries. This option will affect the percentage of
+ the overhead column. See --percentage for more info.
+
+--symbol-filter=::
+ Only show symbols that match (partially) with this filter.
+
+-U::
+--hide-unresolved::
+ Only display entries resolved to a symbol.
+
+-s::
+--sort=::
+ Sort histogram entries by given key(s) - multiple keys can be specified
+ in CSV format. Following sort keys are available:
+ pid, comm, dso, symbol, parent, cpu, socket, srcline, weight,
+ local_weight, cgroup_id.
+
+ Each key has following meaning:
+
+ - comm: command (name) of the task which can be read via /proc/<pid>/comm
+ - pid: command and tid of the task
+ - dso: name of library or module executed at the time of sample
+ - dso_size: size of library or module executed at the time of sample
+ - symbol: name of function executed at the time of sample
+ - symbol_size: size of function executed at the time of sample
+ - parent: name of function matched to the parent regex filter. Unmatched
+ entries are displayed as "[other]".
+ - cpu: cpu number the task ran at the time of sample
+ - socket: processor socket number the task ran at the time of sample
+ - srcline: filename and line number executed at the time of sample. The
+ DWARF debugging info must be provided.
+ - srcfile: file name of the source file of the samples. Requires dwarf
+ information.
+ - weight: Event specific weight, e.g. memory latency or transaction
+ abort cost. This is the global weight.
+ - local_weight: Local weight version of the weight above.
+ - cgroup_id: ID derived from cgroup namespace device and inode numbers.
+ - cgroup: cgroup pathname in the cgroupfs.
+ - transaction: Transaction abort flags.
+ - overhead: Overhead percentage of sample
+ - overhead_sys: Overhead percentage of sample running in system mode
+ - overhead_us: Overhead percentage of sample running in user mode
+ - overhead_guest_sys: Overhead percentage of sample running in system mode
+ on guest machine
+ - overhead_guest_us: Overhead percentage of sample running in user mode on
+ guest machine
+ - sample: Number of sample
+ - period: Raw number of event count of sample
+ - time: Separate the samples by time stamp with the resolution specified by
+ --time-quantum (default 100ms). Specify with overhead and before it.
+
+ By default, comm, dso and symbol keys are used.
+ (i.e. --sort comm,dso,symbol)
+
+ If --branch-stack option is used, following sort keys are also
+ available:
+
+ - dso_from: name of library or module branched from
+ - dso_to: name of library or module branched to
+ - symbol_from: name of function branched from
+ - symbol_to: name of function branched to
+ - srcline_from: source file and line branched from
+ - srcline_to: source file and line branched to
+ - mispredict: "N" for predicted branch, "Y" for mispredicted branch
+ - in_tx: branch in TSX transaction
+ - abort: TSX transaction abort.
+ - cycles: Cycles in basic block
+
+ 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.
+
+ - symbol_daddr: name of data symbol being executed on at the time of sample
+ - dso_daddr: name of library or module containing the data being executed
+ on at the time of the sample
+ - locked: whether the bus was locked at the time of the sample
+ - tlb: type of tlb access for the data at the time of the sample
+ - mem: type of memory access for the data at the time of the sample
+ - snoop: type of snoop (if any) for the data at the time of the sample
+ - dcacheline: the cacheline the data address is on at the time of the sample
+ - phys_daddr: physical address of data being executed on at the time of sample
+
+ And the default sort keys are changed to local_weight, mem, sym, dso,
+ symbol_daddr, dso_daddr, snoop, tlb, locked, see '--mem-mode'.
+
+ If the data file has tracepoint event(s), following (dynamic) sort keys
+ are also available:
+ trace, trace_fields, [<event>.]<field>[/raw]
+
+ - trace: pretty printed trace output in a single column
+ - trace_fields: fields in tracepoints in separate columns
+ - <field name>: optional event and field name for a specific field
+
+ The last form consists of event and field names. If event name is
+ omitted, it searches all events for matching field name. The matched
+ field will be shown only for the event has the field. The event name
+ supports substring match so user doesn't need to specify full subsystem
+ and event name everytime. For example, 'sched:sched_switch' event can
+ be shortened to 'switch' as long as it's not ambiguous. Also event can
+ be specified by its index (starting from 1) preceded by the '%'.
+ So '%1' is the first event, '%2' is the second, and so on.
+
+ The field name can have '/raw' suffix which disables pretty printing
+ and shows raw field value like hex numbers. The --raw-trace option
+ has the same effect for all dynamic sort keys.
+
+ The default sort keys are changed to 'trace' if all events in the data
+ file are tracepoint.
+
+-F::
+--fields=::
+ Specify output field - multiple keys can be specified in CSV format.
+ Following fields are available:
+ overhead, overhead_sys, overhead_us, overhead_children, sample and period.
+ Also it can contain any sort key(s).
+
+ By default, every sort keys not specified in -F will be appended
+ automatically.
+
+ If the keys starts with a prefix '+', then it will append the specified
+ field(s) to the default field order. For example: perf report -F +period,sample.
+
+-p::
+--parent=<regex>::
+ A regex filter to identify parent. The parent is a caller of this
+ function and searched through the callchain, thus it requires callchain
+ information recorded. The pattern is in the extended regex format and
+ defaults to "\^sys_|^do_page_fault", see '--sort parent'.
+
+-x::
+--exclude-other::
+ Only display entries with parent-match.
+
+-w::
+--column-widths=<width[,width...]>::
+ Force each column width to the provided list, for large terminal
+ readability. 0 means no limit (default behavior).
+
+-t::
+--field-separator=::
+ Use a special separator character and don't pad with spaces, replacing
+ all occurrences of this separator in symbol names (and other output)
+ with a '.' character, that thus it's the only non valid separator.
+
+-D::
+--dump-raw-trace::
+ Dump raw trace in ASCII.
+
+-g::
+--call-graph=<print_type,threshold[,print_limit],order,sort_key[,branch],value>::
+ Display call chains using type, min percent threshold, print limit,
+ call order, sort key, optional branch and value. Note that ordering
+ is not fixed so any parameter can be given in an arbitrary order.
+ One exception is the print_limit which should be preceded by threshold.
+
+ print_type can be either:
+ - flat: single column, linear exposure of call chains.
+ - graph: use a graph tree, displaying absolute overhead rates. (default)
+ - fractal: like graph, but displays relative rates. Each branch of
+ the tree is considered as a new profiled object.
+ - folded: call chains are displayed in a line, separated by semicolons
+ - none: disable call chain display.
+
+ threshold is a percentage value which specifies a minimum percent to be
+ included in the output call graph. Default is 0.5 (%).
+
+ print_limit is only applied when stdio interface is used. It's to limit
+ number of call graph entries in a single hist entry. Note that it needs
+ to be given after threshold (but not necessarily consecutive).
+ Default is 0 (unlimited).
+
+ order can be either:
+ - callee: callee based call graph.
+ - caller: inverted caller based call graph.
+ Default is 'caller' when --children is used, otherwise 'callee'.
+
+ sort_key can be:
+ - function: compare on functions (default)
+ - address: compare on individual code addresses
+ - srcline: compare on source filename and line number
+
+ branch can be:
+ - branch: include last branch information in callgraph when available.
+ Usually more convenient to use --branch-history for this.
+
+ value can be:
+ - percent: display overhead percent (default)
+ - period: display event period
+ - count: display event count
+
+--children::
+ Accumulate callchain of children to parent entry so that then can
+ show up in the output. The output will have a new "Children" column
+ and will be sorted on the data. It requires callchains are recorded.
+ See the `overhead calculation' section for more details. Enabled by
+ default, disable with --no-children.
+
+--max-stack::
+ Set the stack depth limit when parsing the callchain, anything
+ beyond the specified depth will be ignored. This is a trade-off
+ between information loss and faster processing especially for
+ workloads that can have a very long callchain stack.
+ Note that when using the --itrace option the synthesized callchain size
+ will override this value if the synthesized callchain size is bigger.
+
+ Default: 127
+
+-G::
+--inverted::
+ alias for inverted caller based call graph.
+
+--ignore-callees=<regex>::
+ Ignore callees of the function(s) matching the given regex.
+ This has the effect of collecting the callers of each such
+ function into one place in the call-graph tree.
+
+--pretty=<key>::
+ Pretty printing style. key: normal, raw
+
+--stdio:: Use the stdio interface.
+
+--stdio-color::
+ 'always', 'never' or 'auto', allowing configuring color output
+ via the command line, in addition to via "color.ui" .perfconfig.
+ Use '--stdio-color always' to generate color even when redirecting
+ to a pipe or file. Using just '--stdio-color' is equivalent to
+ using 'always'.
+
+--tui:: Use the TUI interface, that is integrated with annotate and allows
+ zooming into DSOs or threads, among other features. Use of --tui
+ requires a tty, if one is not present, as when piping to other
+ commands, the stdio interface is used.
+
+--gtk:: Use the GTK2 interface.
+
+-k::
+--vmlinux=<file>::
+ vmlinux pathname
+
+--ignore-vmlinux::
+ Ignore vmlinux files.
+
+--kallsyms=<file>::
+ kallsyms pathname
+
+-m::
+--modules::
+ Load module symbols. WARNING: This should only be used with -k and
+ a LIVE kernel.
+
+-f::
+--force::
+ Don't do ownership validation.
+
+--symfs=<directory>::
+ Look for files with symbols relative to this directory.
+
+-C::
+--cpu:: Only report samples for the list of CPUs provided. Multiple CPUs can
+ be provided as a comma-separated list with no space: 0,1. Ranges of
+ CPUs are specified with -: 0-2. Default is to report samples on all
+ CPUs.
+
+-M::
+--disassembler-style=:: Set disassembler style for objdump.
+
+--source::
+ Interleave source code with assembly code. Enabled by default,
+ disable with --no-source.
+
+--asm-raw::
+ Show raw instruction encoding of assembly instructions.
+
+--show-total-period:: Show a column with the sum of periods.
+
+-I::
+--show-info::
+ Display extended information about the perf.data file. This adds
+ information which may be very large and thus may clutter the display.
+ It currently includes: cpu and numa topology of the host system.
+
+-b::
+--branch-stack::
+ Use the addresses of sampled taken branches instead of the instruction
+ address to build the histograms. To generate meaningful output, the
+ perf.data file must have been obtained using perf record -b or
+ perf record --branch-filter xxx where xxx is a branch filter option.
+ perf report is able to auto-detect whether a perf.data file contains
+ branch stacks and it will automatically switch to the branch view mode,
+ unless --no-branch-stack is used.
+
+--branch-history::
+ Add the addresses of sampled taken branches to the callstack.
+ This allows to examine the path the program took to each sample.
+ The data collection must have used -b (or -j) and -g.
+
+--objdump=<path>::
+ Path to objdump binary.
+
+--prefix=PREFIX::
+--prefix-strip=N::
+ Remove first N entries from source file path names in executables
+ and add PREFIX. This allows to display source code compiled on systems
+ with different file system layout.
+
+--group::
+ Show event group information together. It forces group output also
+ if there are no groups defined in data file.
+
+--group-sort-idx::
+ Sort the output by the event at the index n in group. If n is invalid,
+ sort by the first event. It can support multiple groups with different
+ amount of events. WARNING: This should be used on grouped events.
+
+--demangle::
+ Demangle symbol names to human readable form. It's enabled by default,
+ disable with --no-demangle.
+
+--demangle-kernel::
+ Demangle kernel symbol names to human readable form (for C++ kernels).
+
+--mem-mode::
+ Use the data addresses of samples in addition to instruction addresses
+ to build the histograms. To generate meaningful output, the perf.data
+ file must have been obtained using perf record -d -W and using a
+ special event -e cpu/mem-loads/p or -e cpu/mem-stores/p. See
+ 'perf mem' for simpler access.
+
+--percent-limit::
+ Do not show entries which have an overhead under that percent.
+ (Default: 0). Note that this option also sets the percent limit (threshold)
+ of callchains. However the default value of callchain threshold is
+ different than the default value of hist entries. Please see the
+ --call-graph option for details.
+
+--percentage::
+ Determine how to display the overhead percentage of filtered entries.
+ Filters can be applied by --comms, --dsos and/or --symbols options and
+ Zoom operations on the TUI (thread, dso, etc).
+
+ "relative" means it's relative to filtered entries only so that the
+ sum of shown entries will be always 100%. "absolute" means it retains
+ the original value before and after the filter is applied.
+
+--header::
+ Show header information in the perf.data file. This includes
+ various information like hostname, OS and perf version, cpu/mem
+ info, perf command line, event list and so on. Currently only
+ --stdio output supports this feature.
+
+--header-only::
+ Show only perf.data header (forces --stdio).
+
+--time::
+ Only analyze samples within given time window: <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 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 ranges. Time string is
+ 'a%/n,b%/m,...' or 'a%-b%,c%-%d,...'.
+
+ For example:
+ Select the second 10% time slice:
+
+ perf report --time 10%/2
+
+ Select from 0% to 10% time slice:
+
+ perf report --time 0%-10%
+
+ Select the first and second 10% time slices:
+
+ perf report --time 10%/1,10%/2
+
+ Select from 0% to 10% and 30% to 40% slices:
+
+ perf report --time 0%-10%,30%-40%
+
+--switch-on EVENT_NAME::
+ Only consider events after this event is found.
+
+ This may be interesting to measure a workload only after some initialization
+ phase is over, i.e. insert a perf probe at that point and then using this
+ option with that probe.
+
+--switch-off EVENT_NAME::
+ Stop considering events after this event is found.
+
+--show-on-off-events::
+ Show the --switch-on/off events too. This has no effect in 'perf report' now
+ but probably we'll make the default not to show the switch-on/off events
+ on the --group mode and if there is only one event besides the off/on ones,
+ go straight to the histogram browser, just like 'perf report' with no events
+ explicitely specified does.
+
+--itrace::
+ Options for decoding instruction tracing data. The options are:
+
+include::itrace.txt[]
+
+ To disable decoding entirely, use --no-itrace.
+
+--full-source-path::
+ Show the full path for source files for srcline output.
+
+--show-ref-call-graph::
+ When multiple events are sampled, it may not be needed to collect
+ callgraphs for all of them. The sample sites are usually nearby,
+ and it's enough to collect the callgraphs on a reference event.
+ So user can use "call-graph=no" event modifier to disable callgraph
+ for other events to reduce the overhead.
+ However, perf report cannot show callgraphs for the event which
+ disable the callgraph.
+ This option extends the perf report to show reference callgraphs,
+ which collected by reference event, in no callgraph event.
+
+--stitch-lbr::
+ Show callgraph with stitched LBRs, which may have more complete
+ callgraph. The perf.data file must have been obtained using
+ perf record --call-graph lbr.
+ Disabled by default. In common cases with call stack overflows,
+ it can recreate better call stacks than the default lbr call stack
+ output. But this approach is not full proof. There can be cases
+ where it creates incorrect call stacks from incorrect matches.
+ The known limitations include exception handing such as
+ setjmp/longjmp will have calls/returns not match.
+
+--socket-filter::
+ Only report the samples on the processor socket that match with this filter
+
+--samples=N::
+ Save N individual samples for each histogram entry to show context in perf
+ report tui browser.
+
+--raw-trace::
+ When displaying traceevent output, do not use print fmt or plugins.
+
+--hierarchy::
+ Enable hierarchical output.
+
+--inline::
+ If a callgraph address belongs to an inlined function, the inline stack
+ will be printed. Each entry is function name or file/line. Enabled by
+ default, disable with --no-inline.
+
+--mmaps::
+ Show --tasks output plus mmap information in a format similar to
+ /proc/<PID>/maps.
+
+ Please note that not all mmaps are stored, options affecting which ones
+ are include 'perf record --data', for instance.
+
+--ns::
+ Show time stamps in nanoseconds.
+
+--stats::
+ Display overall events statistics without any further processing.
+ (like the one at the end of the perf report -D command)
+
+--tasks::
+ Display monitored tasks stored in perf data. Displaying pid/tid/ppid
+ plus the command string aligned to distinguish parent and child tasks.
+
+--percent-type::
+ Set annotation percent type from following choices:
+ global-period, local-period, global-hits, local-hits
+
+ The local/global keywords set if the percentage is computed
+ in the scope of the function (local) or the whole data (global).
+ The period/hits keywords set the base the percentage is computed
+ on - the samples period or the number of samples (hits).
+
+--time-quantum::
+ Configure time quantum for time sort key. Default 100ms.
+ Accepts s, us, ms, ns units.
+
+--total-cycles::
+ When --total-cycles is specified, it supports sorting for all blocks by
+ 'Sampled Cycles%'. This is useful to concentrate on the globally hottest
+ blocks. In output, there are some new columns:
+
+ 'Sampled Cycles%' - block sampled cycles aggregation / total sampled cycles
+ 'Sampled Cycles' - block sampled cycles aggregation
+ 'Avg Cycles%' - block average sampled cycles / sum of total block average
+ sampled cycles
+ 'Avg Cycles' - block average sampled cycles
+
+include::callchain-overhead-calculation.txt[]
+
+SEE ALSO
+--------
+linkperf:perf-stat[1], linkperf:perf-annotate[1], linkperf:perf-record[1],
+linkperf:perf-intel-pt[1]