linux/tools/perf/Documentation/perf-mem.txt
Stephane Eranian 67121f85e4 perf mem: Enable sampling loads and stores simultaneously
This patch modifies perf mem to default to sampling loads and stores
simultaneously. It could only do one or the other before yet there was
no hardware restriction preventing simultaneous collection. With this
patch, one run is sufficient to collect both.

It is still possible to sample only loads or stores by using the
-t option:
 $ perf mem -t load rec
 $ perf mem -t load rep
Or
 $ perf mem -t store rec
 $ perf mem -t store rep

The perf report TUI will show one event at a time. The store output will
contain a Weight column which will be empty.

In V2, we updated the man pages to reflect the change and also simplify
the initialization of the argv vector passed to the cmd_*() functions as
per LKML feedback.

In V3, we fixed typos in the changelog.

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Fowles <rfowles@redhat.com>
Link: http://lkml.kernel.org/r/20141217152355.GA10053@thinkpad
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-01-21 13:24:31 -03:00

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perf-mem(1)
===========
NAME
----
perf-mem - Profile memory accesses
SYNOPSIS
--------
[verse]
'perf mem' [<options>] (record [<command>] | report)
DESCRIPTION
-----------
"perf mem record" runs a command and gathers memory operation data
from it, into perf.data. Perf record options are accepted and are passed through.
"perf mem report" displays the result. It invokes perf report with the
right set of options to display a memory access profile. By default, loads
and stores are sampled. Use the -t option to limit to loads or stores.
Note that on Intel systems the memory latency reported is the use-latency,
not the pure load (or store latency). Use latency includes any pipeline
queueing delays in addition to the memory subsystem latency.
OPTIONS
-------
<command>...::
Any command you can specify in a shell.
-t::
--type=::
Select the memory operation type: load or store (default: load,store)
-D::
--dump-raw-samples=::
Dump the raw decoded samples on the screen in a format that is easy to parse with
one sample per line.
-x::
--field-separator::
Specify the field separator used when dump raw samples (-D option). By default,
The separator is the space character.
-C::
--cpu-list::
Restrict dump of raw samples to those provided via this option. Note that the same
option can be passed in record mode. It will be interpreted the same way as perf
record.
SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-report[1]