Commit 97256d1a authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo

perf intel-pt: Rename intel-pt.txt and put it in man page format

Make the Intel PT documentation into a man page.
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200311122034.3697-2-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0c2d0412
Intel Processor Trace
=====================
perf-intel-pt(1)
================
Overview
========
NAME
----
perf-intel-pt - Support for Intel Processor Trace within perf tools
SYNOPSIS
--------
[verse]
'perf record' -e intel_pt//
DESCRIPTION
-----------
Intel Processor Trace (Intel PT) is an extension of Intel Architecture that
collects information about software execution such as control flow, execution
......@@ -43,7 +52,7 @@ vary depending on the use-case and architecture.
Quickstart
==========
----------
It is important to start small. That is because it is easy to capture vastly
more data than can possibly be processed.
......@@ -156,10 +165,10 @@ for more details.
perf record
===========
-----------
new event
---------
~~~~~~~~~
The Intel PT kernel driver creates a new PMU for Intel PT. PMU events are
selected by providing the PMU name followed by the "config" separated by slashes.
......@@ -245,7 +254,7 @@ perf_event_attr is displayed if the -vv option is used e.g.
config terms
------------
~~~~~~~~~~~~
The June 2015 version of Intel 64 and IA-32 Architectures Software Developer
Manuals, Chapter 36 Intel Processor Trace, defined new Intel PT features.
......@@ -435,7 +444,7 @@ pwr_evt Enable power events. The power events provide information about
AUX area sampling option
------------------------
~~~~~~~~~~~~~~~~~~~~~~~~
To select Intel PT "sampling" the AUX area sampling option can be used:
......@@ -485,7 +494,7 @@ but the tool validates that the sample size is not greater than 60KiB.
new snapshot option
-------------------
~~~~~~~~~~~~~~~~~~~
The difference between full trace and snapshot from the kernel's perspective is
that in full trace we don't overwrite trace data that the user hasn't collected
......@@ -514,7 +523,7 @@ The snapshot size is displayed if the option -vv is used e.g.
new auxtrace mmap size option
---------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Intel PT buffer size is specified by an addition to the -m option e.g.
......@@ -547,7 +556,7 @@ The mmap size and auxtrace mmap size are displayed if the -vv option is used e.g
Intel PT modes of operation
---------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~
Intel PT can be used in 2 modes:
full-trace mode
......@@ -577,7 +586,7 @@ The 2 modes cannot be used together.
Buffer handling
---------------
~~~~~~~~~~~~~~~
There may be buffer limitations (i.e. single ToPa entry) which means that actual
buffer sizes are limited to powers of 2 up to 4MiB (MAX_ORDER). In order to
......@@ -601,7 +610,7 @@ data.
Intel PT and build ids
----------------------
~~~~~~~~~~~~~~~~~~~~~~
By default "perf record" post-processes the event stream to find all build ids
for executables for all addresses sampled. Deliberately, Intel PT is not
......@@ -619,7 +628,7 @@ If the perf.data file contains Intel PT data, that is the same as:
Snapshot mode and event disabling
---------------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In order to make a snapshot, the intel_pt event is disabled using an IOCTL,
namely PERF_EVENT_IOC_DISABLE. However doing that can also disable the
......@@ -642,7 +651,7 @@ To run the test:
perf record modes (nothing new here)
------------------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
perf record essentially operates in one of three modes:
per thread
......@@ -668,7 +677,7 @@ mode by using the --per-thread option.
Privileged vs non-privileged users
----------------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Unless /proc/sys/kernel/perf_event_paranoid is set to -1, unprivileged users
have memory limits imposed upon them. That affects what buffer sizes they can
......@@ -697,7 +706,7 @@ be possible to decode Intel PT in per-cpu mode.
sched_switch tracepoint
-----------------------
~~~~~~~~~~~~~~~~~~~~~~~
The sched_switch tracepoint is used to provide side-band data for Intel PT
decoding in kernels where the PERF_RECORD_SWITCH metadata event isn't
......@@ -783,14 +792,14 @@ cannot be matched against the Intel PT trace.
perf script
===========
-----------
By default, perf script will decode trace data found in the perf.data file.
This can be further controlled by new option --itrace.
New --itrace option
-------------------
~~~~~~~~~~~~~~~~~~~
Having no option is the same as
......@@ -913,7 +922,7 @@ at the beginning. This is useful to ignore initialization code.
skips the first million instructions.
dump option
-----------
~~~~~~~~~~~
perf script has an option (-D) to "dump" the events i.e. display the binary
data.
......@@ -931,7 +940,7 @@ To disable the display of Intel PT packets, combine the -D option with
perf report
===========
-----------
By default, perf report will decode trace data found in the perf.data file.
This can be further controlled by new option --itrace exactly the same as
......@@ -939,7 +948,7 @@ perf script, with the exception that the default is --itrace=igxe.
perf inject
===========
-----------
perf inject also accepts the --itrace option in which case tracing data is
removed and replaced with the synthesized events. e.g.
......@@ -977,7 +986,7 @@ that may change in the future if greater use is made of the data.
PEBS via Intel PT
=================
-----------------
Some hardware has the feature to redirect PEBS records to the Intel PT trace.
Recording is selected by using the aux-output config term e.g.
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment