When using 'perf script' to look at PT traces it is often useful to
ignore the initialization code at the beginning.

On larger traces which may have many millions of instructions in
initialization code doing that in a pipeline can be very slow, with perf
script spending a lot of CPU time calling printf and writing data.

This patch adds an extension to the --itrace argument that skips 'n'
events (instructions, branches or transactions) at the beginning. This
is much more efficient.

v2:
Add support for BTS (Adrian Hunter)
Document in itrace.txt
Fix branch check
Check transactions and instructions too

Committer note:

To test intel_pt one needs to make sure VT-x isn't active, i.e.
stopping KVM guests on the test machine, as described by Andi Kleen
at http://lkml.kernel.org/r/20160301234953.GD23621@tassilo.jf.intel.comSigned-off-by: NAndi Kleen <ak@linux.intel.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1459187142-20035-1-git-send-email-andi@firstfloor.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

All over the tree.

Cc: David Ahern <dsahern@gmail.com>
cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-8nzhnokxyp8y4v7gf0j00oyb@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

On some architecture the size of the private header may be dependent on
the number of tracers used in the session.  As such adding a "struct
perf_evlist *" parameter, which should contain all the required
information.

Also adjusting the existing client of the interface to take the new
parameter into account.
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Al Grant <al.grant@arm.com>
Cc: Chunyan Zhang <zhang.chunyan@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: Mike Leach <mike.leach@arm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rabin Vincent <rabin@rab.in>
Cc: Tor Jeremiassen <tor@ti.com>
Link: http://lkml.kernel.org/r/1452807977-8069-22-git-send-email-mathieu.poirier@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add AUX area tracing option 'l' to synthesize branch stacks on samples
just like sample type PERF_SAMPLE_BRANCH_STACK.  This is taken into use
by Intel PT in a subsequent patch.
Based-on-patch-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1443186956-18718-9-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Intel BTS support fits within the new auxtrace infrastructure.  Recording is
supporting by identifying the Intel BTS PMU, parsing options and setting up
events.

Decoding is supported by queuing up trace data by thread and then decoding
synchronously delivering synthesized event samples into the session processing
for tools to consume.

Committer note:

E.g:

  [root@felicio ~]# perf record --per-thread -e intel_bts// ls
  anaconda-ks.cfg  apctest.output  bin  kernel-rt-3.10.0-298.rt56.171.el7.x86_64.rpm  libexec  lock_page.bpf.c  perf.data  perf.data.old
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 4.367 MB perf.data ]
  [root@felicio ~]# perf evlist -v
  intel_bts//: type: 6, size: 112, { sample_period, sample_freq }: 1, sample_type: IP|TID|IDENTIFIER, read_format: ID, disabled: 1, enable_on_exec: 1, sample_id_all: 1, exclude_guest: 1
  dummy:u: type: 1, size: 112, config: 0x9, { sample_period, sample_freq }: 1, sample_type: IP|TID|IDENTIFIER, read_format: ID, disabled: 1, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, mmap2: 1, comm_exec: 1
  [root@felicio ~]# perf script # the navigate in the pager to some interesting place:
    ls 1843 1 branches: ffffffff810a60cb flush_signal_handlers ([kernel.kallsyms]) => ffffffff8121a522 setup_new_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8121a529 setup_new_exec ([kernel.kallsyms]) => ffffffff8122fa30 do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122fa5d do_close_on_exec ([kernel.kallsyms]) => ffffffff81767ae0 _raw_spin_lock ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff81767af4 _raw_spin_lock ([kernel.kallsyms]) => ffffffff8122fa62 do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122fa8e do_close_on_exec ([kernel.kallsyms]) => ffffffff8122faf0 do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122faf7 do_close_on_exec ([kernel.kallsyms]) => ffffffff8122fa8b do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122fa8e do_close_on_exec ([kernel.kallsyms]) => ffffffff8122faf0 do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122faf7 do_close_on_exec ([kernel.kallsyms]) => ffffffff8122fa8b do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122fa8e do_close_on_exec ([kernel.kallsyms]) => ffffffff8122faf0 do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122faf7 do_close_on_exec ([kernel.kallsyms]) => ffffffff8122fa8b do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122fa8e do_close_on_exec ([kernel.kallsyms]) => ffffffff8122faf0 do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122faf7 do_close_on_exec ([kernel.kallsyms]) => ffffffff8122fa8b do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122fa8e do_close_on_exec ([kernel.kallsyms]) => ffffffff8122faf0 do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122faf7 do_close_on_exec ([kernel.kallsyms]) => ffffffff8122fa8b do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122fa8e do_close_on_exec ([kernel.kallsyms]) => ffffffff8122faf0 do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122faf7 do_close_on_exec ([kernel.kallsyms]) => ffffffff8122fa8b do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122fac9 do_close_on_exec ([kernel.kallsyms]) => ffffffff8122fad2 do_close_on_exec ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8122fadd do_close_on_exec ([kernel.kallsyms]) => ffffffff8120fc80 filp_close ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8120fcaf filp_close ([kernel.kallsyms]) => ffffffff8120fcb6 filp_close ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8120fcc2 filp_close ([kernel.kallsyms]) => ffffffff812547f0 dnotify_flush ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff81254823 dnotify_flush ([kernel.kallsyms]) => ffffffff8120fcc7 filp_close ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8120fccd filp_close ([kernel.kallsyms]) => ffffffff81261790 locks_remove_posix ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff812617a3 locks_remove_posix ([kernel.kallsyms]) => ffffffff812617b9 locks_remove_posix ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff812617b9 locks_remove_posix ([kernel.kallsyms]) => ffffffff8120fcd2 filp_close ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8120fcd5 filp_close ([kernel.kallsyms]) => ffffffff812142c0 fput ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff812142d6 fput ([kernel.kallsyms]) => ffffffff812142df fput ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff8121430c fput ([kernel.kallsyms]) => ffffffff810b6580 task_work_add ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff810b65ad task_work_add ([kernel.kallsyms]) => ffffffff810b65b1 task_work_add ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff810b65c1 task_work_add ([kernel.kallsyms]) => ffffffff810bc710 kick_process ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff810bc725 kick_process ([kernel.kallsyms]) => ffffffff810bc742 kick_process ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff810bc742 kick_process ([kernel.kallsyms]) => ffffffff810b65c6 task_work_add ([kernel.kallsyms])
    ls 1843 1 branches: ffffffff810b65c9 task_work_add ([kernel.kallsyms]) => ffffffff81214311 fput ([kernel.kallsyms])
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1437150840-31811-9-git-send-email-adrian.hunter@intel.com
[ Merged sample->time fix for bug found after first round of testing on slightly older kernel ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add the Intel Processor Trace type constant PERF_AUXTRACE_INTEL_PT.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1437150840-31811-2-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Allow auxtrace data to be a multiple of something other than page size.
That is needed for BTS where the buffer contains 24-byte records.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1432906425-9911-11-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add a new option and support for Instruction Tracing Snapshot Mode.
When the new option is selected, no AUX area tracing data is captured
until a signal (SIGUSR2) is received.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1430404667-10593-10-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add support for making snapshots of AUX area tracing data.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1430404667-10593-9-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add AUX area tracing option 'x' to synthesize events for transactions.
This will be used by Intel PT to synthesize an event record for each TSX
start, commit or abort.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1430404667-10593-6-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add build option NO_AUXTRACE to exclude compiling support for AUX area
tracing. Support for both recording and processing is excluded and by
implication any future additions such as Intel PT and Intel BTS will
also not be compiled in with this option.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1430404667-10593-5-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add an index of AUX area tracing events within a perf.data file.

perf record uses a special user event PERF_RECORD_FINISHED_ROUND to
enable sorting of events in chunks instead of having to sort all events
altogether.

AUX area tracing events contain data that can span back to the very
beginning of the recording period. i.e. they do not obey the rules of
PERF_RECORD_FINISHED_ROUND.

By adding an index, AUX area tracing events can be found in advance and
the PERF_RECORD_FINISHED_ROUND approach works as usual.

The index is recorded with the auxtrace feature in the perf.data file.
A session reads the index but does not process it.  An AUX area decoder
can queue all the AUX area data in advance using
auxtrace_queues__process_index() or otherwise process the index in some
custom manner.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1430404667-10593-3-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Decoding AUX area data may involve walking object code.  Rather than
repetitively decoding the same instructions, a cache can be used to
cache the results.

This patch implements a fairly generic hashtable with a 32-bit key that
could be used for other purposes as well.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-15-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Provide hooks so that an AUX area decoder can process AUX area tracing
events.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-14-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

In order to process AUX area tracing data in time order, the queue with
data with the lowest timestamp must be processed first.  Provide a heap
to keep track of which queue that is.

As with the queues, a decoder does not have to use the heap, but Intel
BTS and Intel PT will use it.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-13-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Provide functions to queue AUX area tracing data buffers for processing.
A AUX area decoder need not use the queues, however Intel BTS and Intel
PT will use them.

There is one queue for each of the mmap buffers that were used for
recording.  Because those mmaps were associated with per-cpu or
per-thread contexts, the data is time-ordered with respect to those
contexts.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1429608111-18160-1-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add functions to synthesize, count and print AUX area tracing error
events.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-11-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

It is assumed that AUX area decoding will synthesize events for
consumption by other tools.

At this time, the main use of AUX area tracing will be to capture
instruction trace (aka processor trace) data.

The nature of instruction tracing suggests the initial inclusion of
options for "instructions" and "branches" events, but more could be
added as needed.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-10-git-send-email-adrian.hunter@intel.com
[ Added ref to tools/perf/Documentation/perf-script.txt describing what is parsed ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Hook into session processing so that AUX area decoding can synthesize
events transparently to the tools.

The advantages of transparent decoding are that tools can be used
directly with perf.data files containing AUX area tracing data, which is
easier for the user and more efficient than having a separate decoding
tool.

This will work as follows:

1. Tools will feed auxtrace events to the decoder using
   perf_tool->auxtrace() (support for that still to come).

2. The decoder can process side-band events as needed due
   to the auxtrace->process_event() hook.

3. The decoder can deliver synthesized events into the
   event stream using perf_session__deliver_synth_event().

Note the expectation is that decoding will work on data that is
time-ordered with respect to the per-cpu or per-thread contexts that
were recorded.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-9-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add support for reading from the AUX area tracing mmap and synthesizing
AUX area tracing events.

This patch introduces an abstraction for recording AUX area data.

Recording is initialized by auxtrace_record__init() which is a weak
function to be implemented by the architecture to provide recording
callbacks.

Recording is mainly handled by auxtrace_mmap__read() and
perf_event__synthesize_auxtrace() but there are callbacks for
miscellaneous needs including validating and processing user options,
populating private data in auxtrace_info_event, and freeing the
structure when finished.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-5-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch supports the addition to the kernel of AUX area buffers that
can be mmapped separately from the perf-events buffer.

The AUX buffer can be configured to contain hardware-produced trace
information. The first implementation will support Intel BTS and Intel
PT.

One auxtrace buffer is mmapped per perf-events buffer.  If the requested
auxtrace buffer size is zero, which it will be until further support is
added, then no auxtrace mmapping is attempted.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-3-git-send-email-adrian.hunter@intel.com
[ Fixed conflict in evlist.h ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>