Specification claims latest version of jitdump file format is 2. Current
jit dump reading code treats 1 as the latest version.
Correct spec to match code.
The original language made it unclear the value to be written in the
magic field.
Revise language that the writer always writes the same value. Specify
that the reader uses the value to detect endian mismatches.
Signed-off-by: Steve MacLean <Steve.MacLean@Microsoft.com>
Acked-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Brian Robbins <brianrob@microsoft.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Keeping <john@metanate.com>
Cc: John Salem <josalem@microsoft.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Tom McDonald <thomas.mcdonald@microsoft.com>
Link: http://lore.kernel.org/lkml/BN8PR21MB1362F63CDE7AC69736FC7F9EF7800@BN8PR21MB1362.namprd21.prod.outlook.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
With this change if a perf_date parameter is provided to asciidoc then
it will override the default date written to the man page metadata.
Without this change, or if the perf_date isn't specified, then the
current date is written to the metadata.
Having this parameter allows the metadata to be constant if builds
happen on different dates.
The name of the parameter is intended to be consistent with the existing
perf_version parameter.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20190921041327.155054-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Just like 'perf trace' and 'perf script', should be useful for instance
to only consider samples after the initialization phase of some
workload.
The man page has some examples and considerations about its current
interface, that still doesn't handle the on/off events in a special way,
behaving just like when multiple events are specified, i.e.:
- In non-group mode (when the event list is not enclosed in {}) show a
a menu to allow choosing which event the user wants to see in the
histograms browser
- In group mode, be it using {} or asking for --group, show one column
per event.
Try for instance:
# perf top -e '{cycles,instructions,probe:icmp_rcv}' --switch-on=probe:icmp_rcv
Replace probe:icmp_rcv, that I put in place using:
# perf probe icmp_rcv:59
To hit when broadcast packets arrive, with a probe installed after an
initialization phase is over or after some other point of interest, some
garbage collection, etc, and also use --switch-off, for instance, on a
probe installed after said garbage collection is over.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: William Cohen <wcohen@redhat.com>
Link: https://lkml.kernel.org/n/tip-c7q7qjeqtyvc9mkeipxza6ne@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf.data file format documentation for HEADER_SAMPLE_TOPOLOGY
specifies the layout in a confusing manner that doesn't match the rest
of the document. This patch attempts to describe things consistent with
the rest of the file.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Chong Jiang <chongjiang@chromium.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1908011425240.14303@macbook-air
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Document how to select PEBS via Intel PT and how to display synthesized
PEBS samples.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190806084606.4021-8-alexander.shishkin@linux.intel.com
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
[ Update the example to use a group with intel_pt// as the group leader, as per Alex comment ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Expose the aux_output attribute flag to the user to configure, by adding a
config term 'aux-output'. For events that support it, selection of
'aux-output' causes the generation of AUX records instead of event records.
This requires that an AUX area event is also provided.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190806084606.4021-7-alexander.shishkin@linux.intel.com
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add itrace option 'o' to synthesize events recorded in the AUX area due
to the use of perf record's aux-output config term.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190806084606.4021-5-alexander.shishkin@linux.intel.com
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It is sometimes useful to generate a snapshot when perf record exits;
I've been using a wrapper script around the workload that would do a
killall -USR2 perf when the workload exits.
This patch makes it easier and also works when perf record is attached
to a pre-existing task. A new snapshot option 'e' can be specified in
-S to enable this behavior:
root@elsewhere:~# perf record -e intel_pt// -Se sleep 1
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.085 MB perf.data ]
Co-developed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190806144101.62892-1-alexander.shishkin@linux.intel.com
[ Fixed up !HAVE_AUXTRACE_SUPPORT build in builtin-record.c, adding 2 missing __maybe_unused ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There was a provision for setting this variable, but not the
getenv("PERF_CONFIG") call to set it, as this was fixed in the previous
cset, document that it can be used to ask for using an alternative
.perfconfig file or to disable reading whatever file exists in the
system or home directory, i.e. using:
export PERF_CONFIG=/dev/null
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Link: https://lkml.kernel.org/n/tip-0u4o967hsk7j0o50zp9ctn89@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch fix a spelling typo in a variable name in the Documentation Makefile.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190801032812.25018-1-standby24x7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf.data-file-format documentation incorrectly says the
HEADER_TOTAL_MEM results are in bytes. The results are in kilobytes
(perf reads the value from /proc/meminfo)
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1907251155500.22624@macbook-air
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf.data:
Alexey Budankov:
- Fix loading of compressed data split across adjacent records
Jiri Olsa:
- Fix buffer size setting for processing CPU topology perf.data header.
perf stat:
Jiri Olsa:
- Fix segfault for event group in repeat mode
Cong Wang:
- Always separate "stalled cycles per insn" line, it was being appended to
the "instructions" line.
perf script:
Andi Kleen:
- Fix --max-blocks man page description.
- Improve man page description of metrics.
- Fix off by one in brstackinsn IPC computation.
perf probe:
Arnaldo Carvalho de Melo:
- Avoid calling freeing routine multiple times for same pointer.
perf build:
- Do not use -Wshadow on gcc < 4.8, avoiding too strict warnings
treated as errors, breaking the build.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQR2GiIUctdOfX2qHhGyPKLppCJ+JwUCXTcpSQAKCRCyPKLppCJ+
J0s1AQCY4uEiw7ZDUMPkztqG/9nder8M4ncd2FYwsQObmjxhBQEA+u/jvJ9UcUKk
X9BpjDE+1Pi3LrMaFjDQMKgpSutzXgg=
=rAom
-----END PGP SIGNATURE-----
Merge tag 'perf-urgent-for-mingo-5.3-20190723' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
perf.data:
Alexey Budankov:
- Fix loading of compressed data split across adjacent records
Jiri Olsa:
- Fix buffer size setting for processing CPU topology perf.data header.
perf stat:
Jiri Olsa:
- Fix segfault for event group in repeat mode
Cong Wang:
- Always separate "stalled cycles per insn" line, it was being appended to
the "instructions" line.
perf script:
Andi Kleen:
- Fix --max-blocks man page description.
- Improve man page description of metrics.
- Fix off by one in brstackinsn IPC computation.
perf probe:
Arnaldo Carvalho de Melo:
- Avoid calling freeing routine multiple times for same pointer.
perf build:
- Do not use -Wshadow on gcc < 4.8, avoiding too strict warnings
treated as errors, breaking the build.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Clarify that a metric is based on events, not referring to itself. Also
some improvements with the sentences.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190711181922.18765-3-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The --max-blocks description was using the old name brstackasm. Use
brstackinsn instead.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190711181922.18765-1-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
- Add user space specific memory reading for kprobes
- Allow kprobes to be executed earlier in boot
The rest are mostly just various clean ups and small fixes.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXS88txQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qhaPAQDHaAmu6wXtZjZE6GU4ZP61UNgDECmZ
4wlGrNc1AAlqAQD/QC8339p37aDCp9n27VY1wmJwF3nca+jAHfQLqWkkYgw=
=n/tz
-----END PGP SIGNATURE-----
Merge tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"The main changes in this release include:
- Add user space specific memory reading for kprobes
- Allow kprobes to be executed earlier in boot
The rest are mostly just various clean ups and small fixes"
* tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
tracing: Make trace_get_fields() global
tracing: Let filter_assign_type() detect FILTER_PTR_STRING
tracing: Pass type into tracing_generic_entry_update()
ftrace/selftest: Test if set_event/ftrace_pid exists before writing
ftrace/selftests: Return the skip code when tracing directory not configured in kernel
tracing/kprobe: Check registered state using kprobe
tracing/probe: Add trace_event_call accesses APIs
tracing/probe: Add probe event name and group name accesses APIs
tracing/probe: Add trace flag access APIs for trace_probe
tracing/probe: Add trace_event_file access APIs for trace_probe
tracing/probe: Add trace_event_call register API for trace_probe
tracing/probe: Add trace_probe init and free functions
tracing/uprobe: Set print format when parsing command
tracing/kprobe: Set print format right after parsed command
kprobes: Fix to init kprobes in subsys_initcall
tracepoint: Use struct_size() in kmalloc()
ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS
ftrace: Enable trampoline when rec count returns back to one
tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline
tracing: Make a separate config for trace event self tests
...
- Fix a typo in the man page
- Fix a tip that doesn't make any sense.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190628220900.13741-1-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Documentation the new computation selection 'cycles'.
v4:
---
Change the column 'Block cycles diff [start:end]' to
'[Program Block Range] Cycles Diff'
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1561713784-30533-8-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently only a single explicit time range is accepted. Add support for
multiple ranges separated by spaces, which requires the string to be
quoted. Update the time utils test accordingly.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190604130017.31207-20-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Correct some punctuation and spelling and correct the format to show
that the time resolution is nanoseconds not microseconds.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190604130017.31207-16-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The clang bpf cmdline template has defined default value in the file
tools/perf/util/llvm-utils.c, which has been changed for several times.
This patch updates the documentation to reflect the latest default value
for the configuration llvm.clang-bpf-cmd-template.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Drayton <mbd@fb.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Fixes: d35b168c3d ("perf bpf: Give precedence to bpf header dir")
Fixes: cb76371441 ("perf llvm: Allow passing options to llc in addition to clang")
Fixes: 1b16fffa38 ("perf llvm-utils: Add bpf include path to clang command line")
Link: http://lkml.kernel.org/r/20190607143508.18141-1-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The 'die' info isn't in the same array as core and socket ids, and we
missed the 'dies' string list, that comes right after the 'core' +
'socket' id variable length array, followed by the VLA for the dies.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: c9cb12c5ba08 ("perf header: Add die information in CPU topology")
Link: https://lkml.kernel.org/n/tip-nubi6mxp2n8ofvlx7ph6k3h6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The "sibling cores" actually shows the sibling CPUs of a socket. The
name "sibling cores" is very misleading.
Rename "sibling cores" to "sibling sockets"
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1559688644-106558-4-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It is useful to aggregate counts per die. E.g. Uncore becomes die-scope
on Xeon Cascade Lake-AP.
Introduce a new option "--per-die" to support per-die aggregation.
The global id for each core has been changed to socket + die id + core
id. The global id for each die is socket + die id.
Add die information for per-core aggregation. The output of per-core
aggregation will be changed from "S0-C0" to "S0-D0-C0". Any scripts
which rely on the output format of per-core aggregation probably be
broken.
For 'perf stat record/report', there is no die information when
processing the old perf.data. The per-die result will be the same as
per-socket.
Committer notes:
Renamed 'die' variable to 'die_id' to fix the build in some systems:
CC /tmp/build/perf/builtin-script.o
cc1: warnings being treated as errors
builtin-stat.c: In function 'perf_env__get_die':
builtin-stat.c:963: error: declaration of 'die' shadows a global declaration
util/util.h:19: error: shadowed declaration is here
mv: cannot stat `/tmp/build/perf/.builtin-stat.o.tmp': No such file or directory
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/n/tip-bsnhx7vgsuu6ei307mw60mbj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
With the new CPUID.1F, a new level type of CPU topology, 'die', is
introduced. The 'die' information in CPU topology should be added in
perf header.
To be compatible with old perf.data, the patch checks the section size
before reading the die information. The new info is added at the end of
the cpu_topology section, the old perf tool ignores the extra data. It
never reads data crossing the section boundary.
The new perf tool with the patch can be used on legacy kernel. Add a new
function has_die_topology() to check if die topology information is
supported by kernel. The function only check X86 and CPU 0. Assuming
other CPUs have same topology.
Use similar method for core and socket to support die id and sibling
dies string.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1559688644-106558-2-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
One can just record callchains in the kernel or user space with this new
options.
We can use it together with "--all-kernel" options.
This two options is used just like print_stack(sys) or print_ustack(usr)
for systemtap.
Shown below is the usage of this new option combined with "--all-kernel"
options:
1. Configure all used events to run in kernel space and just collect
kernel callchains.
$ perf record -a -g --all-kernel --kernel-callchains
2. Configure all used events to run in kernel space and just collect
user callchains.
$ perf record -a -g --all-kernel --user-callchains
Committer notes:
Improved documentation to state that asking for kernel callchains really
is asking for excluding user callchains, and vice versa.
Further mentioned that using both won't get both, but nothing, as both
will be excluded.
Signed-off-by: yuzhoujian <yuzhoujian@didichuxing.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1559222962-22891-1-git-send-email-ufo19890607@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add brief documentation to explain how the database export maintains
backward and forward compatibility.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190520113728.14389-15-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add brief documentation about instructions-per-cycle (IPC) information
derived from Intel PT.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190520113728.14389-13-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add field 'ipc' to display instructions-per-cycle.
Example:
perf record -e intel_pt/cyc/u ls
perf script --insn-trace --xed -F+ipc,-dso,-cpu,-tid
ls 2670177.697113434: 7f0dfdbcd090 _start+0x0 mov %rsp, %rdi IPC: 0.00 (1/877)
ls 2670177.697113434: 7f0dfdbcd093 _start+0x3 callq 0x7f0dfdbce030
ls 2670177.697113434: 7f0dfdbce030 _dl_start+0x0 pushq %rbp
ls 2670177.697113434: 7f0dfdbce031 _dl_start+0x1 mov %rsp, %rbp
ls 2670177.697113434: 7f0dfdbce034 _dl_start+0x4 pushq %r15
ls 2670177.697113434: 7f0dfdbce036 _dl_start+0x6 pushq %r14
ls 2670177.697113434: 7f0dfdbce038 _dl_start+0x8 pushq %r13
ls 2670177.697113434: 7f0dfdbce03a _dl_start+0xa pushq %r12
ls 2670177.697113434: 7f0dfdbce03c _dl_start+0xc mov %rdi, %r12
ls 2670177.697113434: 7f0dfdbce03f _dl_start+0xf pushq %rbx
ls 2670177.697113434: 7f0dfdbce040 _dl_start+0x10 sub $0x38, %rsp
ls 2670177.697113434: 7f0dfdbce044 _dl_start+0x14 rdtsc
ls 2670177.697113434: 7f0dfdbce046 _dl_start+0x16 mov %eax, %eax
ls 2670177.697113434: 7f0dfdbce048 _dl_start+0x18 shl $0x20, %rdx
ls 2670177.697113434: 7f0dfdbce04c _dl_start+0x1c or %rax, %rdx
ls 2670177.697114471: 7f0dfdbce04f _dl_start+0x1f movq 0x27e22(%rip), %rax IPC: 0.00 (15/1685)
ls 2670177.697116177: 7f0dfdbce056 _dl_start+0x26 movq %rdx, 0x27683(%rip) IPC: 0.00 (1/881)
Note, the IPC values are low due to page faults at the beginning of
execution. The additional cycles are due to the time to enter the
kernel, not the actual kernel page fault handler.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190520113728.14389-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We forgot to update the perf.data file format document for the
HEADER_DIR_FORMAT header, do it now from comments in the patch
introducing it.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Chong Jiang <chongjiang@chromium.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Fixes: 258031c017 ("perf header: Add DIR_FORMAT feature to describe directory data")
Link: https://lkml.kernel.org/n/tip-jbrzb7ijb5al33gi8br6f9rr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We forgot to update the perf.data file format document for the
HEADER_CLOCKID header, do it now from comments in the patch introducing
it.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Chong Jiang <chongjiang@chromium.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Fixes: cf7905165f ("perf record: Encode -k clockid frequency into Perf trace")
Link: https://lkml.kernel.org/n/tip-slhnjp06027j3ae17qqetzxj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We forgot to update the perf.data file format document for the
HEADER_MEM_TOPOLOGY header, do it now from comments in the patch
introducing it.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Chong Jiang <chongjiang@chromium.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Simon Que <sque@chromium.org>
Fixes: e2091cedd5 ("perf tools: Add MEM_TOPOLOGY feature to perf data file")
Link: https://lkml.kernel.org/n/tip-h5lcm1nbe9ztxwm61gmadd56@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch addes description of HEADER_BPF_PROG_INFO and HEADER_BPF_BTF to
perf.data-file-format.txt.
Requested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 606f972b13 ("perf bpf: Save bpf_prog_info information as headers to perf.data")
Link: http://lkml.kernel.org/r/20190521064406.2498925-1-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add the --show-bpf-events command line option to show the eBPF related events:
PERF_RECORD_KSYMBOL
PERF_RECORD_BPF_EVENT
Usage:
# perf record -a
...
# perf script --show-bpf-events
...
swapper 0 [000] 0.000000: PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc0ef971d len 229 type 1 flags 0x0 name bpf_prog_2a142ef67aaad174
swapper 0 [000] 0.000000: PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 36
...
Committer testing:
# perf script --show-bpf-events | egrep -i 'PERF_RECORD_(BPF|KSY)'
0 PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc029a6c3 len 229 type 1 flags 0x0 name bpf_prog_7be49e3934a125ba
0 PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 47
0 PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc029c1ae len 229 type 1 flags 0x0 name bpf_prog_2a142ef67aaad174
0 PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 48
0 PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc02ddd1c len 229 type 1 flags 0x0 name bpf_prog_7be49e3934a125ba
0 PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 49
0 PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc02dfc11 len 229 type 1 flags 0x0 name bpf_prog_2a142ef67aaad174
0 PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 50
0 PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc045da0a len 229 type 1 flags 0x0 name bpf_prog_7be49e3934a125ba
0 PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 51
0 PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc04ef4b4 len 229 type 1 flags 0x0 name bpf_prog_2a142ef67aaad174
0 PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 52
0 PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc09e15da len 229 type 1 flags 0x0 name bpf_prog_7be49e3934a125ba
0 PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 53
0 PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc0d2b1a3 len 229 type 1 flags 0x0 name bpf_prog_2a142ef67aaad174
0 PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 54
0 PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc0fd9850 len 381 type 1 flags 0x0 name bpf_prog_819967866022f1e1_sys_enter
0 PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 179
0 PERF_RECORD_KSYMBOL ksymbol event with addr ffffffffc0feb1ec len 191 type 1 flags 0x0 name bpf_prog_c1bd85c092d6e4aa_sys_exit
0 PERF_RECORD_BPF_EVENT bpf event with type 1, flags 0, id 180
^C[root@quaco pt]# perf evlist
intel_pt//ku
dummy:u
#
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190508132010.14512-11-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since 'perf record' already have this option, let's have it for 'perf top'
as well.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Krister Johansen <kjlx@templeofstupid.com>
Link: http://lkml.kernel.org/r/20190522053250.207156-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add user memory access attribute for kprobe event arguments.
If a given 'local variable' is in user-space, User can
specify memory access method by '@user' suffix. This is
not only for string but also for data structure.
If we access a field of data structure in user memory from
kernel on some arch, it will fail. e.g.
perf probe -a "sched_setscheduler param->sched_priority"
This will fail to access the "param->sched_priority" because
the param is __user pointer. Instead, we can now specify
@user suffix for such argument.
perf probe -a "sched_setscheduler param->sched_priority@user"
Note that kernel memory access with "@user" must always fail
on any arch.
Link: http://lkml.kernel.org/r/155789874562.26965.10836126971405890891.stgit@devnote2
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With this patch, we can use the 'percore' event qualifier in perf-stat.
root@skl:/tmp# perf stat -e cpu/event=0,umask=0x3,percore=1/,cpu/event=0,umask=0x3/ -a -A -I1000
1.000773050 S0-C0 98,352,832 cpu/event=0,umask=0x3,percore=1/ (50.01%)
1.000773050 S0-C1 103,763,057 cpu/event=0,umask=0x3,percore=1/ (50.02%)
1.000773050 S0-C2 196,776,995 cpu/event=0,umask=0x3,percore=1/ (50.02%)
1.000773050 S0-C3 176,493,779 cpu/event=0,umask=0x3,percore=1/ (50.02%)
1.000773050 CPU0 47,699,641 cpu/event=0,umask=0x3/ (50.02%)
1.000773050 CPU1 49,052,451 cpu/event=0,umask=0x3/ (49.98%)
1.000773050 CPU2 102,771,422 cpu/event=0,umask=0x3/ (49.98%)
1.000773050 CPU3 100,784,662 cpu/event=0,umask=0x3/ (49.98%)
1.000773050 CPU4 43,171,342 cpu/event=0,umask=0x3/ (49.98%)
1.000773050 CPU5 54,152,158 cpu/event=0,umask=0x3/ (49.98%)
1.000773050 CPU6 93,618,410 cpu/event=0,umask=0x3/ (49.98%)
1.000773050 CPU7 74,477,589 cpu/event=0,umask=0x3/ (49.99%)
In this example, we count the event 'ref-cycles' per-core and per-CPU in
one perf stat command-line. From the output, we can see:
S0-C0 = CPU0 + CPU4
S0-C1 = CPU1 + CPU5
S0-C2 = CPU2 + CPU6
S0-C3 = CPU3 + CPU7
So the result is expected (tiny difference is ignored).
Note that, the 'percore' event qualifier needs to use with option '-A'.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1555077590-27664-4-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add a 'percore' event qualifier, like cpu/event=0,umask=0x3,percore=1/,
that sums up the event counts for both hardware threads in a core.
We can already do this with --per-core, but it's often useful to do
this together with other metrics that are collected per hardware thread.
So we need to support this per-core counting on a event level.
This can be implemented in only the user tool, no kernel support needed.
v4:
---
1. Add Arnaldo's patch which updates the documentation for
this new qualifier.
2. Rebase to latest perf/core branch
v3:
---
Simplify the code according to Jiri's comments.
Before:
"return term->val.percore ? true : false;"
Now:
"return term->val.percore;"
v2:
---
Change the qualifier name from 'coresum' to 'percore' according to
comments from Jiri and Andi.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1555077590-27664-2-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
'perf report' displays recorded data on the screen and emits warnings
and debug messages in the status line (last one on screen).
perf also supports the possibility to write all debug messages to stderr
(instead of writing them to the status line).
This is achieved with the following command:
# ./perf --debug stderr=1 report -vvvvv -i ~/fast.data 2>/tmp/2
# ll /tmp/2
-rw-rw-r-- 1 tmricht tmricht 5420835 May 7 13:46 /tmp/2
#
The usage of variable stderr=1 is not documented, so add it to the perf
man page.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20190513080220.91966-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The available registers for --int-regs and --user-regs may be different,
e.g. XMM registers.
Split parse_regs into two dedicated functions for --int-regs and
--user-regs respectively.
Modify the warning message. "--user-regs=?" should be applied to show
the available registers for --user-regs.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1557865174-56264-1-git-send-email-kan.liang@linux.intel.com
[ Changed docs as suggested by Ravi and agreed by Kan ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Implemented -z,--compression_level[=<n>] option that enables compression
of mmaped kernel data buffers content in runtime during perf record mode
collection. Default option value is 1 (fastest compression).
Compression overhead has been measured for serial and AIO streaming when
profiling matrix multiplication workload:
-------------------------------------------------------------
| SERIAL | AIO-1 |
----------------------------------------------------------------|
|-z | OVH(x) | ratio(x) size(MiB) | OVH(x) | ratio(x) size(MiB) |
|---------------------------------------------------------------|
| 0 | 1,00 | 1,000 179,424 | 1,00 | 1,000 187,527 |
| 1 | 1,04 | 8,427 181,148 | 1,01 | 8,474 188,562 |
| 2 | 1,07 | 8,055 186,953 | 1,03 | 7,912 191,773 |
| 3 | 1,04 | 8,283 181,908 | 1,03 | 8,220 191,078 |
| 5 | 1,09 | 8,101 187,705 | 1,05 | 7,780 190,065 |
| 8 | 1,05 | 9,217 179,191 | 1,12 | 6,111 193,024 |
-----------------------------------------------------------------
OVH = (Execution time with -z N) / (Execution time with -z 0)
ratio - compression ratio
size - number of bytes that was compressed
size ~= trace size x ratio
Committer notes:
Testing it I noticed that it failed to disable build id processing when
compression is enabled, and as we'd have to uncompress everything to
look for the PERF_RECORD_{MMAP,SAMPLE,etc} to figure out which build ids
to read from DSOs, we better disable build id processing when
compression is enabled, logging with pr_debug() when doing so:
Original patch:
# perf record -z2
^C[ perf record: Woken up 1 times to write data ]
0x1746e0 [0x76]: failed to process type: 81 [Invalid argument]
[ perf record: Captured and wrote 1.568 MB perf.data, compressed (original 0.452 MB, ratio is 3.995) ]
#
After auto-disabling build id processing when compression is enabled:
$ perf record -z2 sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.001 MB perf.data, compressed (original 0.001 MB, ratio is 2.292) ]
$ perf record -v -z2 sleep 1
Compression enabled, disabling build id collection at the end of the session.
<SNIP extra -v pr_debug() messages>
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.001 MB perf.data, compressed (original 0.001 MB, ratio is 2.305) ]
$
Also, with parts of the patch originally after this one moved to just
before this one we get:
$ perf record -z2 sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.001 MB perf.data, compressed (original 0.001 MB, ratio is 2.371) ]
$ perf report -D | grep COMPRESS
0 0x1b8 [0x155]: PERF_RECORD_COMPRESSED: unhandled!
0 0x30d [0x80]: PERF_RECORD_COMPRESSED: unhandled!
COMPRESSED events: 2
COMPRESSED events: 0
$
I.e. when faced with PERF_RECORD_COMPRESSED that we still have no code
to process, we just show it as not being handled, skip them and
continue, while before we had:
$ perf report -D | grep COMPRESS
0x1b8 [0x169]: failed to process type: 81 [Invalid argument]
Error:
failed to process sample
0 0x1b8 [0x169]: PERF_RECORD_COMPRESSED
$
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/9ff06518-ae63-a908-e44d-5d9e56dd66d9@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Implemented PERF_RECORD_COMPRESSED event, related data types, header
feature and functions to write, read and print feature attributes from
the trace header section.
comp_mmap_len preserves the size of mmaped kernel buffer that was used
during collection. comp_mmap_len size is used on loading stage as the
size of decomp buffer for decompression of COMPRESSED events content.
Committer notes:
Fixed up conflict with BPF_PROG_INFO and BTF_BTF header features.
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/ebbaf031-8dda-3864-ebc6-7922d43ee515@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Implement a --mmap-flush option that specifies minimal number of bytes
that is extracted from mmaped kernel buffer to store into a trace. The
default option value is 1 byte what means every time trace writing
thread finds some new data in the mmaped buffer the data is extracted,
possibly compressed and written to a trace.
$ tools/perf/perf record --mmap-flush 1024 -e cycles -- matrix.gcc
$ tools/perf/perf record --aio --mmap-flush 1K -e cycles -- matrix.gcc
The option is independent from -z setting, doesn't vary with compression
level and can serve two purposes.
The first purpose is to increase the compression ratio of a trace data.
Larger data chunks are compressed more effectively so the implemented
option allows specifying data chunk size to compress. Also at some cases
executing more write syscalls with smaller data size can take longer
than executing less write syscalls with bigger data size due to syscall
overhead so extracting bigger data chunks specified by the option value
could additionally decrease runtime overhead.
The second purpose is to avoid self monitoring live-lock issue in system
wide (-a) profiling mode. Profiling in system wide mode with compression
(-a -z) can additionally induce data into the kernel buffers along with
the data from monitored processes. If performance data rate and volume
from the monitored processes is high then trace streaming and
compression activity in the tool is also high. High tool process
activity can lead to subtle live-lock effect when compression of single
new byte from some of mmaped kernel buffer leads to generation of the
next single byte at some mmaped buffer. So perf tool process ends up in
endless self monitoring.
Implemented synch parameter is the mean to force data move independently
from the specified flush threshold value. Despite the provided flush
value the tool needs capability to unconditionally drain memory buffers,
at least in the end of the collection.
Committer testing:
Running with the default value, i.e. as soon as there is something to
read go on consuming, we first write the synthesized events, small
chunks of about 128 bytes:
# perf trace -m 2048 --call-graph dwarf -e write -- perf record
<SNIP>
101.142 ( 0.004 ms): perf/25821 write(fd: 3</root/perf.data>, buf: 0x210db60, count: 120) = 120
__libc_write (/usr/lib64/libpthread-2.28.so)
ion (/home/acme/bin/perf)
record__write (inlined)
process_synthesized_event (/home/acme/bin/perf)
perf_tool__process_synth_event (inlined)
perf_event__synthesize_mmap_events (/home/acme/bin/perf)
Then we move to reading the mmap buffers consuming the events put there
by the kernel perf infrastructure:
107.561 ( 0.005 ms): perf/25821 write(fd: 3</root/perf.data>, buf: 0x7f1befc02000, count: 336) = 336
__libc_write (/usr/lib64/libpthread-2.28.so)
ion (/home/acme/bin/perf)
record__write (inlined)
record__pushfn (/home/acme/bin/perf)
perf_mmap__push (/home/acme/bin/perf)
record__mmap_read_evlist (inlined)
record__mmap_read_all (inlined)
__cmd_record (inlined)
cmd_record (/home/acme/bin/perf)
12919.953 ( 0.136 ms): perf/25821 write(fd: 3</root/perf.data>, buf: 0x7f1befc83150, count: 184984) = 184984
<SNIP same backtrace as in the 107.561 timestamp>
12920.094 ( 0.155 ms): perf/25821 write(fd: 3</root/perf.data>, buf: 0x7f1befc02150, count: 261816) = 261816
<SNIP same backtrace as in the 107.561 timestamp>
12920.253 ( 0.093 ms): perf/25821 write(fd: 3</root/perf.data>, buf: 0x7f1befb81120, count: 170832) = 170832
<SNIP same backtrace as in the 107.561 timestamp>
If we limit it to write only when more than 16MB are available for
reading, it throttles that to a quarter of the --mmap-pages set for
'perf record', which by default get to 528384 bytes, found out using
'record -v':
mmap flush: 132096
mmap size 528384B
With that in place all the writes coming from
record__mmap_read_evlist(), i.e. from the mmap buffers setup by the
kernel perf infrastructure were at least 132096 bytes long.
Trying with a bigger mmap size:
perf trace -e write perf record -v -m 2048 --mmap-flush 16M
74982.928 ( 2.471 ms): perf/26500 write(fd: 3</root/perf.data>, buf: 0x7ff94a6cc000, count: 3580888) = 3580888
74985.406 ( 2.353 ms): perf/26500 write(fd: 3</root/perf.data>, buf: 0x7ff949ecb000, count: 3453256) = 3453256
74987.764 ( 2.629 ms): perf/26500 write(fd: 3</root/perf.data>, buf: 0x7ff9496ca000, count: 3859232) = 3859232
74990.399 ( 2.341 ms): perf/26500 write(fd: 3</root/perf.data>, buf: 0x7ff948ec9000, count: 3769032) = 3769032
74992.744 ( 2.064 ms): perf/26500 write(fd: 3</root/perf.data>, buf: 0x7ff9486c8000, count: 3310520) = 3310520
74994.814 ( 2.619 ms): perf/26500 write(fd: 3</root/perf.data>, buf: 0x7ff947ec7000, count: 4194688) = 4194688
74997.439 ( 2.787 ms): perf/26500 write(fd: 3</root/perf.data>, buf: 0x7ff9476c6000, count: 4029760) = 4029760
Was again limited to a quarter of the mmap size:
mmap flush: 2098176
mmap size 8392704B
A warning about that would be good to have but can be added later,
something like:
"max flush is a quarter of the mmap size, if wanting to bump the mmap
flush further, bump the mmap size as well using -m/--mmap-pages"
Also rename the 'sync' parameters to 'synch' to keep tools/perf building
with older glibcs:
cc1: warnings being treated as errors
builtin-record.c: In function 'record__mmap_read_evlist':
builtin-record.c:775: warning: declaration of 'sync' shadows a global declaration
/usr/include/unistd.h:933: warning: shadowed declaration is here
builtin-record.c: In function 'record__mmap_read_all':
builtin-record.c:856: warning: declaration of 'sync' shadows a global declaration
/usr/include/unistd.h:933: warning: shadowed declaration is here
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/f6600d72-ecfa-2eb7-7e51-f6954547d500@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
