change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/tools/perf/Documentation/perf-report.txt
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@@ -89,12 +89,13 @@
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 	- socket: processor socket number the task ran at the time of sample
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 	- srcline: filename and line number executed at the time of sample.  The
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 	DWARF debugging info must be provided.
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-	- srcfile: file name of the source file of the same. Requires dwarf
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+	- srcfile: file name of the source file of the samples. Requires dwarf
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 	information.
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 	- weight: Event specific weight, e.g. memory latency or transaction
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 	abort cost. This is the global weight.
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 	- local_weight: Local weight version of the weight above.
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 	- cgroup_id: ID derived from cgroup namespace device and inode numbers.
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+	- cgroup: cgroup pathname in the cgroupfs.
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 	- transaction: Transaction abort flags.
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 	- overhead: Overhead percentage of sample
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 	- overhead_sys: Overhead percentage of sample running in system mode
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@@ -105,6 +106,8 @@
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 	guest machine
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 	- sample: Number of sample
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 	- period: Raw number of event count of sample
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+	- time: Separate the samples by time stamp with the resolution specified by
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+	--time-quantum (default 100ms). Specify with overhead and before it.
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 	By default, comm, dso and symbol keys are used.
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 	(i.e. --sort comm,dso,symbol)
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@@ -125,6 +128,14 @@
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 	And default sort keys are changed to comm, dso_from, symbol_from, dso_to
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 	and symbol_to, see '--branch-stack'.
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+
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+	When the sort key symbol is specified, columns "IPC" and "IPC Coverage"
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+	are enabled automatically. Column "IPC" reports the average IPC per function
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+	and column "IPC coverage" reports the percentage of instructions with
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+	sampled IPC in this function. IPC means Instruction Per Cycle. If it's low,
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+	it indicates there may be a performance bottleneck when the function is
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+	executed, such as a memory access bottleneck. If a function has high overhead
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+	and low IPC, it's worth further analyzing it to optimize its performance.
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 	If the --mem-mode option is used, the following sort keys are also available
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 	(incompatible with --branch-stack):
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@@ -244,7 +255,7 @@
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 	          Usually more convenient to use --branch-history for this.
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 	value can be:
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-	- percent: diplay overhead percent (default)
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+	- percent: display overhead percent (default)
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 	- period: display event period
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 	- count: display event count
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@@ -357,9 +368,20 @@
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 --objdump=<path>::
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         Path to objdump binary.
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+--prefix=PREFIX::
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+--prefix-strip=N::
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+	Remove first N entries from source file path names in executables
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+	and add PREFIX. This allows to display source code compiled on systems
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+	with different file system layout.
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+
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 --group::
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 	Show event group information together. It forces group output also
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 	if there are no groups defined in data file.
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+
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+--group-sort-idx::
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+	Sort the output by the event at the index n in group. If n is invalid,
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+	sort by the first event. It can support multiple groups with different
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+	amount of events. WARNING: This should be used on grouped events.
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 --demangle::
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 	Demangle symbol names to human readable form. It's enabled by default,
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@@ -402,12 +424,13 @@
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 --time::
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 	Only analyze samples within given time window: <start>,<stop>. Times
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-	have the format seconds.microseconds. If start is not given (i.e., time
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+	have the format seconds.nanoseconds. If start is not given (i.e. time
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 	string is ',x.y') then analysis starts at the beginning of the file. If
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-	stop time is not given (i.e, time string is 'x.y,') then analysis goes
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-	to end of file.
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+	stop time is not given (i.e. time string is 'x.y,') then analysis goes
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+	to end of file. Multiple ranges can be separated by spaces, which
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+	requires the argument to be quoted e.g. --time "1234.567,1234.789 1235,"
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-	Also support time percent with multiple time range. Time string is
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+	Also support time percent with multiple time ranges. Time string is
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 	'a%/n,b%/m,...' or 'a%-b%,c%-%d,...'.
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 	For example:
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@@ -426,6 +449,23 @@
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 	Select from 0% to 10% and 30% to 40% slices:
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 	  perf report --time 0%-10%,30%-40%
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+
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+--switch-on EVENT_NAME::
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+	Only consider events after this event is found.
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+
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+	This may be interesting to measure a workload only after some initialization
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+	phase is over, i.e. insert a perf probe at that point and then using this
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+	option with that probe.
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+
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+--switch-off EVENT_NAME::
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+	Stop considering events after this event is found.
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+
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+--show-on-off-events::
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+	Show the --switch-on/off events too. This has no effect in 'perf report' now
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+	but probably we'll make the default not to show the switch-on/off events
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+        on the --group mode and if there is only one event besides the off/on ones,
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+	go straight to the histogram browser, just like 'perf report' with no events
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+	explicitely specified does.
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 --itrace::
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 	Options for decoding instruction tracing data. The options are:
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@@ -448,8 +488,23 @@
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 	This option extends the perf report to show reference callgraphs,
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 	which collected by reference event, in no callgraph event.
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+--stitch-lbr::
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+	Show callgraph with stitched LBRs, which may have more complete
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+	callgraph. The perf.data file must have been obtained using
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+	perf record --call-graph lbr.
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+	Disabled by default. In common cases with call stack overflows,
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+	it can recreate better call stacks than the default lbr call stack
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+	output. But this approach is not full proof. There can be cases
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+	where it creates incorrect call stacks from incorrect matches.
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+	The known limitations include exception handing such as
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+	setjmp/longjmp will have calls/returns not match.
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+
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 --socket-filter::
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 	Only report the samples on the processor socket that match with this filter
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+
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+--samples=N::
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+	Save N individual samples for each histogram entry to show context in perf
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+	report tui browser.
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 --raw-trace::
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 	When displaying traceevent output, do not use print fmt or plugins.
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@@ -469,6 +524,9 @@
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 	Please note that not all mmaps are stored, options affecting which ones
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 	are include 'perf record --data', for instance.
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+--ns::
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+	Show time stamps in nanoseconds.
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+
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 --stats::
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 	Display overall events statistics without any further processing.
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 	(like the one at the end of the perf report -D command)
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@@ -486,8 +544,24 @@
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 	The period/hits keywords set the base the percentage is computed
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 	on - the samples period or the number of samples (hits).
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+--time-quantum::
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+	Configure time quantum for time sort key. Default 100ms.
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+	Accepts s, us, ms, ns units.
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+
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+--total-cycles::
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+	When --total-cycles is specified, it supports sorting for all blocks by
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+	'Sampled Cycles%'. This is useful to concentrate on the globally hottest
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+	blocks. In output, there are some new columns:
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+	'Sampled Cycles%' - block sampled cycles aggregation / total sampled cycles
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+	'Sampled Cycles'  - block sampled cycles aggregation
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+	'Avg Cycles%'     - block average sampled cycles / sum of total block average
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+			    sampled cycles
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+	'Avg Cycles'      - block average sampled cycles
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+
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 include::callchain-overhead-calculation.txt[]
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 SEE ALSO
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 --------
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-linkperf:perf-stat[1], linkperf:perf-annotate[1], linkperf:perf-record[1]
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+linkperf:perf-stat[1], linkperf:perf-annotate[1], linkperf:perf-record[1],
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+linkperf:perf-intel-pt[1]