alistair23-linux/tools/perf/Documentation/itrace.txt
Andi Kleen 4eb0681571 perf script: Make itrace script default to all calls
By default 'perf script' for itrace outputs sampled instructions or
branches. In my experience this is confusing to users because it's hard
to correlate with real program behavior. The sampling makes sense for
tools like 'perf report' that actually sample to reduce the run time,
but run time is normally not a problem for 'perf script'.  It's better
to give an accurate representation of the program flow.

Default 'perf script' to output all calls for itrace. That's a much saner
default. The old behavior can be still requested with 'perf script'
--itrace=ibxwpe100000

v2: Fix ETM build failure
v3: Really fix ETM build failure (Kim Phillips)

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Link: http://lkml.kernel.org/r/20180920180540.14039-3-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-10-24 15:29:54 -03:00

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i synthesize instructions events
b synthesize branches events
c synthesize branches events (calls only)
r synthesize branches events (returns only)
x synthesize transactions events
w synthesize ptwrite events
p synthesize power events
e synthesize error events
d create a debug log
g synthesize a call chain (use with i or x)
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,
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.
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.