Each key has following meaning:

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.

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

Default: 127

"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.

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%

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.

i        synthesize instructions events
y        synthesize cycles events
b        synthesize branches events (branch misses for Arm SPE)
c        synthesize branches events (calls only)
r        synthesize branches events (returns only)
x        synthesize transactions events
w        synthesize ptwrite events
p        synthesize power events (incl. PSB events for Intel PT)
o        synthesize other events recorded due to the use


        of aux-output (refer to perf record)
I        synthesize interrupt or similar (asynchronous) events


        (e.g. Intel PT Event Trace)
e        synthesize error events
d        create a debug log
f        synthesize first level cache events
m        synthesize last level cache events
M        synthesize memory events
t        synthesize TLB events
a        synthesize remote access events
g        synthesize a call chain (use with i or x)
G        synthesize a call chain on existing event records
l        synthesize last branch entries (use with i or x)
L        synthesize last branch entries on existing event records
s       skip initial number of events
q        quicker (less detailed) decoding
A        approximate IPC
Z        prefer to ignore timestamps (so-called "timeless" decoding)
T        use the timestamp trace as kernel time

The default is all events i.e. the same as --itrace=iybxwpe,
except for perf script where it is --itrace=ce

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
ms        milliseconds
us        microseconds
ns        nanoseconds (default)

Also the call chain size (default 16, max. 1024) for instructions or
transactions events can be specified.

Also the number of last branch entries (default 64, max. 1024) for
instructions or transactions events can be specified.

Similar to options g and l, size may also be specified for options G and L.
On x86, note that G and L work poorly when data has been recorded with
large PEBS. Refer linkperf:perf-intel-pt[1] man page for details.

It is also possible to skip events generated (instructions, branches, transactions,
ptwrite, power) at the beginning. This is useful to ignore initialization code.

--itrace=i0nss1000000

skips the first million instructions.

The 'e' option may be followed by flags which affect what errors will or
will not be reported. Each flag must be preceded by either '+' or '-'.
The flags are:


        o        overflow


        l        trace data lost

If supported, the 'd' option may be followed by flags which affect what
debug messages will or will not be logged. Each flag must be preceded
by either '+' or '-'. The flags are:


        a        all perf events


        e        output only on errors (size configurable - see linkperf:perf-config[1])


        o        output to stdout

If supported, the 'q' option may be repeated to increase the effect.

To disable decoding entirely, use --no-itrace.

For example:
In normal output:

perf report -s dso,sym
# Overhead  Shared Object      Symbol


    50.00%  [kernel.kallsyms]  [k] kfunc1


    20.00%  perf               [.] foo


    15.00%  [kernel.kallsyms]  [k] kfunc2


    10.00%  perf               [.] bar


     5.00%  libc.so            [.] libcall

In hierarchy output:

perf report -s dso,sym --hierarchy
#   Overhead  Shared Object / Symbol


    65.00%    [kernel.kallsyms]


      50.00%    [k] kfunc1


      15.00%    [k] kfunc2


    30.00%    perf


      20.00%    [.] foo


      10.00%    [.] bar


     5.00%    libc.so


       5.00%    [.] libcall

Please note that not all mmaps are stored, options affecting which ones
are include 'perf record --data', for instance.

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).

'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