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Subject[PATCH 00/15] perf tools: Add support for AUX area sampling
Date
Hi

The kernel changes for AUX area sampling are now in tip, so here are the
tools' patches.

AUX area sampling allows bytes from a AUX area buffer to be copied onto
samples of other events.

Here is the Intel PT documentation from patch "perf intel-pt: Add support
for recording AUX area":

perf record AUX area sampling option
------------------------

To select Intel PT "sampling" the AUX area sampling option can be used:

--aux-sample

Optionally it can be followed by the sample size in bytes e.g.

--aux-sample=8192

In addition, the Intel PT event to sample must be defined e.g.

-e intel_pt//u

Samples on other events will be created containing Intel PT data e.g. the
following will create Intel PT samples on the branch-misses event, note the
events must be grouped using {}:

perf record --aux-sample -e '{intel_pt//u,branch-misses:u}'

An alternative to '--aux-sample' is to add the config term 'aux-sample-size' to
events. In this case, the grouping is implied e.g.

perf record -e intel_pt//u -e branch-misses/aux-sample-size=8192/u

is the same as:

perf record -e '{intel_pt//u,branch-misses/aux-sample-size=8192/u}'

but allows for also using an address filter e.g.:

perf record -e intel_pt//u --filter 'filter * @/bin/ls' -e branch-misses/aux-sample-size=8192/u -- ls

It is important to select a sample size that is big enough to contain at least
one PSB packet. If not a warning will be displayed:

Intel PT sample size (%zu) may be too small for PSB period (%zu)

The calculation used for that is: if sample_size <= psb_period + 256 display the
warning. When sampling is used, psb_period defaults to 0 (2KiB).

The default sample size is 4KiB.

The sample size is passed in aux_sample_size in struct perf_event_attr. The
sample size is limited by the maximum event size which is 64KiB. It is
difficult to know how big the event might be without the trace sample attached,
but the tool validates that the sample size is not greater than 60KiB.


Adrian Hunter (15):
perf tools: Add kernel AUX area sampling definitions
perf tools: Add AUX area sample parsing
perf tools: Add a function to test for kernel support for AUX area sampling
perf auxtrace: Move perf_evsel__find_pmu()
perf auxtrace: Add support for AUX area sample recording
perf record: Add support for AUX area sampling
perf record: Add aux-sample-size config term
perf inject: Cut AUX area samples
perf auxtrace: Add support for dumping AUX area samples
perf session: Add facility to peek at all events
perf auxtrace: Add support for queuing AUX area samples
perf pmu: When using default config, record which bits of config were changed by the user
perf intel-pt: Add support for recording AUX area samples
perf intel-pt: Add support for decoding AUX area samples
perf intel-bts: Does not support AUX area sampling

tools/include/uapi/linux/perf_event.h | 10 +-
tools/perf/Documentation/intel-pt.txt | 59 +++++-
tools/perf/Documentation/perf-record.txt | 9 +
tools/perf/arch/x86/util/auxtrace.c | 4 +
tools/perf/arch/x86/util/intel-bts.c | 5 +
tools/perf/arch/x86/util/intel-pt.c | 81 +++++++-
tools/perf/builtin-inject.c | 29 +++
tools/perf/builtin-record.c | 21 +-
tools/perf/tests/attr/base-record | 2 +-
tools/perf/tests/attr/base-stat | 2 +-
tools/perf/tests/sample-parsing.c | 16 +-
tools/perf/util/auxtrace.c | 322 ++++++++++++++++++++++++++++--
tools/perf/util/auxtrace.h | 42 ++++
tools/perf/util/event.h | 6 +
tools/perf/util/evlist.h | 1 +
tools/perf/util/evsel.c | 31 +++
tools/perf/util/evsel_config.h | 13 ++
tools/perf/util/intel-pt.c | 109 +++++++++-
tools/perf/util/parse-events.c | 56 +++++-
tools/perf/util/parse-events.h | 1 +
tools/perf/util/parse-events.l | 1 +
tools/perf/util/perf_event_attr_fprintf.c | 3 +-
tools/perf/util/pmu.c | 10 +
tools/perf/util/pmu.h | 2 +
tools/perf/util/record.c | 30 +++
tools/perf/util/record.h | 2 +
tools/perf/util/session.c | 38 +++-
tools/perf/util/session.h | 5 +
tools/perf/util/synthetic-events.c | 12 ++
29 files changed, 894 insertions(+), 28 deletions(-)


Regards
Adrian

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