It's used by bpftool and the kernel build. Let's add a feature test so
that perf can decide what to do based on the availability.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Pull perf tools updates from Namhyung Kim:
"Perf event/metric description:
Unify all event and metric descriptions in JSON format. Now event
parsing and handling is greatly simplified by that.
From users point of view, perf list will provide richer information
about hardware events like the following.
$ perf list hw
List of pre-defined events (to be used in -e or -M):
legacy hardware:
branch-instructions
[Retired branch instructions [This event is an alias of branches]. Unit: cpu]
branch-misses
[Mispredicted branch instructions. Unit: cpu]
branches
[Retired branch instructions [This event is an alias of branch-instructions]. Unit: cpu]
bus-cycles
[Bus cycles,which can be different from total cycles. Unit: cpu]
cache-misses
[Cache misses. Usually this indicates Last Level Cache misses; this is intended to be used in conjunction with the
PERF_COUNT_HW_CACHE_REFERENCES event to calculate cache miss rates. Unit: cpu]
cache-references
[Cache accesses. Usually this indicates Last Level Cache accesses but this may vary depending on your CPU. This may include
prefetches and coherency messages; again this depends on the design of your CPU. Unit: cpu]
cpu-cycles
[Total cycles. Be wary of what happens during CPU frequency scaling [This event is an alias of cycles]. Unit: cpu]
cycles
[Total cycles. Be wary of what happens during CPU frequency scaling [This event is an alias of cpu-cycles]. Unit: cpu]
instructions
[Retired instructions. Be careful,these can be affected by various issues,most notably hardware interrupt counts. Unit: cpu]
ref-cycles
[Total cycles; not affected by CPU frequency scaling. Unit: cpu]
But most notable changes would be in the perf stat. On the right side,
the default metrics are better named and aligned. :)
$ perf stat -- perf test -w noploop
Performance counter stats for 'perf test -w noploop':
11 context-switches # 10.8 cs/sec cs_per_second
0 cpu-migrations # 0.0 migrations/sec migrations_per_second
3,612 page-faults # 3532.5 faults/sec page_faults_per_second
1,022.51 msec task-clock # 1.0 CPUs CPUs_utilized
110,466 branch-misses # 0.0 % branch_miss_rate (88.66%)
6,934,452,104 branches # 6781.8 M/sec branch_frequency (88.66%)
4,657,032,590 cpu-cycles # 4.6 GHz cycles_frequency (88.65%)
27,755,874,218 instructions # 6.0 instructions insn_per_cycle (89.03%)
TopdownL1 # 0.3 % tma_backend_bound
# 9.3 % tma_bad_speculation (89.05%)
# 9.7 % tma_frontend_bound (77.86%)
# 80.7 % tma_retiring (88.81%)
1.025318171 seconds time elapsed
1.013248000 seconds user
0.012014000 seconds sys
Deferred unwinding support:
With the kernel support (commit c69993ecdd: "perf: Support deferred
user unwind"), perf can use deferred callchains for userspace stack
trace with frame pointers like below:
$ perf record --call-graph fp,defer ...
This will be transparent to users when it comes to other commands like
perf report and perf script. They will merge the deferred callchains
to the previous samples as if they were collected together.
ARM SPE updates
- Extensive enhancements to support various kinds of memory
operations including GCS, MTE allocation tags, memcpy/memset,
register access, and SIMD operations.
- Add inverted data source filter (inv_data_src_filter) support to
exclude certain data sources.
- Improve documentation.
Vendor event updates:
- Intel: Updated event files for Sierra Forest, Panther Lake, Meteor
Lake, Lunar Lake, Granite Rapids, and others.
- Arm64: Added metrics for i.MX94 DDR PMU and Cortex-A720AE
definitions.
- RISC-V: Added JSON support for T-HEAD C920V2.
Misc:
- Improve pointer tracking in data type profiling. It'd give better
output when the variable is using container_of() to convert type.
- Annotation support for perf c2c report in TUI. Press 'a' key to
enter annotation view from cacheline browser window. This will show
which instruction is causing the cacheline contention.
- Lots of fixes and test coverage improvements!"
* tag 'perf-tools-for-v6.19-2025-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (214 commits)
libperf: Use 'extern' in LIBPERF_API visibility macro
perf stat: Improve handling of termination by signal
perf tests stat: Add test for error for an offline CPU
perf stat: When no events, don't report an error if there is none
perf tests stat: Add "--null" coverage
perf cpumap: Add "any" CPU handling to cpu_map__snprint_mask
libperf cpumap: Fix perf_cpu_map__max for an empty/NULL map
perf stat: Allow no events to open if this is a "--null" run
perf test kvm: Add some basic perf kvm test coverage
perf tests evlist: Add basic evlist test
perf tests script dlfilter: Add a dlfilter test
perf tests kallsyms: Add basic kallsyms test
perf tests timechart: Add a perf timechart test
perf tests top: Add basic perf top coverage test
perf tests buildid: Add purge and remove testing
perf tests c2c: Add a basic c2c
perf c2c: Clean up some defensive gets and make asan clean
perf jitdump: Fix missed dso__put
perf mem-events: Don't leak online CPU map
perf hist: In init, ensure mem_info is put on error paths
...
This feature test is no longer used so remove.
The function tested by the feature test is used in:
tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
however, the Makefile just assumes the presence of the function and
doesn't perform a build feature test for it.
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
perf doesn't use libtracefs and so it doesn't make sense to assume it is
always available when building test-all.bin, defeating the feature check
speedup it provides.
The other tools/build/ users such as rtla, rv, etc call $(feature_check
libtracefs) to check its availability instead of using the test-all.bin
mechanism, stopping the build and asking for libtracefs-devel to be
installed.
Remove it from FEATURE_TESTS_BASIC to not have it as available, as noted
by Ian Rogers during review.
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Tomas Glozar <tglozar@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If libperl is installed then the perf tool build will build against
it. There appears to be limited interest in the scripting support for
perl so let's make it opt-in and deprecate it.
With this patch applied you need to add LIBPERL=1 to get libperl
support in perf - there is no warning if libperl is missing, but
building will fail if libperl is missing and the build has LIBPERL=1.
The perf version output is changed to:
```
$ perf version --build-options
perf version 6.17.rc3.g8eca69269947
aio: [ on ] # HAVE_AIO_SUPPORT
bpf: [ on ] # HAVE_LIBBPF_SUPPORT
bpf_skeletons: [ on ] # HAVE_BPF_SKEL
debuginfod: [ on ] # HAVE_DEBUGINFOD_SUPPORT
dwarf: [ on ] # HAVE_LIBDW_SUPPORT
dwarf_getlocations: [ on ] # HAVE_LIBDW_SUPPORT
dwarf-unwind: [ on ] # HAVE_DWARF_UNWIND_SUPPORT
auxtrace: [ on ] # HAVE_AUXTRACE_SUPPORT
libbfd: [ OFF ] # HAVE_LIBBFD_SUPPORT ( tip: Deprecated, license incompatibility, use BUILD_NONDISTRO=1 and install binutils-dev[el] )
libbpf-strings: [ on ] # HAVE_LIBBPF_STRINGS_SUPPORT
libcapstone: [ on ] # HAVE_LIBCAPSTONE_SUPPORT
libdw-dwarf-unwind: [ on ] # HAVE_LIBDW_SUPPORT
libelf: [ on ] # HAVE_LIBELF_SUPPORT
libnuma: [ on ] # HAVE_LIBNUMA_SUPPORT
libopencsd: [ OFF ] # HAVE_CSTRACE_SUPPORT
libperl: [ OFF ] # HAVE_LIBPERL_SUPPORT ( tip:
Deprecated, use LIBPERL=1 and install libperl-dev to build with it )
libpfm4: [ on ] # HAVE_LIBPFM
libpython: [ on ] # HAVE_LIBPYTHON_SUPPORT
libslang: [ on ] # HAVE_SLANG_SUPPORT
libtraceevent: [ on ] # HAVE_LIBTRACEEVENT
libunwind: [ OFF ] # HAVE_LIBUNWIND_SUPPORT ( tip:
Deprecated, use LIBUNWIND=1 and install libunwind-dev[el] to build
with it )
lzma: [ on ] # HAVE_LZMA_SUPPORT
numa_num_possible_cpus: [ on ] # HAVE_LIBNUMA_SUPPORT
zlib: [ on ] # HAVE_ZLIB_SUPPORT
zstd: [ on ] # HAVE_ZSTD_SUPPORT
```
i.e. there is a tip saying about deprecation and how to get support
back.
Signed-off-by: Ian Rogers <irogers@google.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: Charlie Jenkins <charlie@rivosinc.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <qmo@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Yuzhuo Jing <yuzhuo@google.com>
Link: https://lore.kernel.org/lkml/aMrk03gigBlGcYLK@x1/
Link: https://lore.kernel.org/lkml/CAP-5=fVX+bLBRJCiziDi_hBySgv2NFtDoghtpheSSxVAvvETGw@mail.gmail.com
[ Keep the pre-existing perl-ExtUtils-Embed hint for Fedora/RHEL systems ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This creates a config option that detects libbpf's ability to display
character arrays as strings, which was just added to the BPF tree
(https://git.kernel.org/bpf/bpf-next/c/87c9c79a02b4).
To test this change, I built perf (from later in this patch set) with:
- static libbpf (default, using source from kernel tree)
- dynamic libbpf (LIBBPF_DYNAMIC=1 LIBBPF_INCLUDE=/usr/local/include)
For both the static and dynamic versions, I used headers with and without
the ".emit_strings" option.
I verified that of the four resulting binaries, the two with
".emit_strings" would successfully record BPF_METADATA events, and the two
without wouldn't. All four binaries would successfully display
BPF_METADATA events, because the relevant bit of libbpf code is only used
during "perf record".
Signed-off-by: Blake Jones <blakejones@google.com>
Link: https://lore.kernel.org/r/20250612194939.162730-2-blakejones@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Since dd317df072 ("perf build: Make binutil libraries opt in")
doesn't try to build with binutils libraries, so showing that it is OFF
when building causes just distraction, remove it from FEATURES_DISPLAY.
For people that for some reason notice that there is always 'perf -vv',
a short hand for 'perf version --build-options' and 'perf check feature
libbfd' that now explains why it is not built:
$ perf check feature libbfd
libbfd: [ OFF ] # HAVE_LIBBFD_SUPPORT ( tip: Deprecated, license incompatibility, use BUILD_NONDISTRO=1 and install binutils-dev[el] )
$
Fixes: dd317df072 ("perf build: Make binutil libraries opt in")
Tested-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ian Rogers <irogers@google.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: https://lore.kernel.org/r/Z--pWmTHGb62_83e@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since 13e17c9ff4 ("perf build: Make libunwind opt-in rather than
opt-out") doesn't try to build with libunwind, so showing that it is OFF
when building causes just distraction, remove it from FEATURES_DISPLAY.
For people that for some reason notice that there is always 'perf -vv',
a short hand for 'perf version --build-options' and 'perf check feature
libunwind' that now explains why it is not built:
$ perf check feature libunwind
libunwind: [ OFF ] # HAVE_LIBUNWIND_SUPPORT ( tip: Deprecated, use LIBUNWIND=1 and install libunwind-dev[el] to build with it )
$
Fixes: 13e17c9ff4 ("perf build: Make libunwind opt-in rather than opt-out")
Reported-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ian Rogers <irogers@google.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: https://lore.kernel.org/r/Z--pWmTHGb62_83e@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The tools/build/feature/test-all.c file tries to detect the expected,
most common set of libraries/features we expect to have available to
build perf with.
At some point libunwind was deemed not to be part of that set of
libries, but the patches making it to be opt-in ended up forgetting some
details, fix one more.
Testing it:
$ rm -rf /tmp/build/$(basename $PWD)/ ; mkdir -p /tmp/build/$(basename $PWD)/
$ rpm -q libunwind-devel
libunwind-devel-1.8.0-3.fc40.x86_64
$ make -k LIBUNWIND=1 CORESIGHT=1 O=/tmp/build/$(basename $PWD)/ -C tools/perf install-bin |& grep unwind && ldd ~/bin/perf | grep unwind
... libunwind: [ on ]
CC /tmp/build/perf-tools-next/arch/x86/tests/dwarf-unwind.o
CC /tmp/build/perf-tools-next/arch/x86/util/unwind-libunwind.o
CC /tmp/build/perf-tools-next/util/arm64-frame-pointer-unwind-support.o
CC /tmp/build/perf-tools-next/tests/dwarf-unwind.o
CC /tmp/build/perf-tools-next/util/unwind-libunwind-local.o
CC /tmp/build/perf-tools-next/util/unwind-libunwind.o
libunwind-x86_64.so.8 => /lib64/libunwind-x86_64.so.8 (0x00007f615a549000)
libunwind.so.8 => /lib64/libunwind.so.8 (0x00007f615a52f000)
$ sudo rpm -e libunwind-devel
$ rm -rf /tmp/build/$(basename $PWD)/ ; mkdir -p /tmp/build/$(basename $PWD)/
$ make -k LIBUNWIND=1 CORESIGHT=1 O=/tmp/build/$(basename $PWD)/ -C tools/perf install-bin |& grep unwind && ldd ~/bin/perf | grep unwind
Makefile.config:653: No libunwind found. Please install libunwind-dev[el] >= 1.1 and/or set LIBUNWIND_DIR
... libunwind: [ OFF ]
CC /tmp/build/perf-tools-next/arch/x86/tests/dwarf-unwind.o
CC /tmp/build/perf-tools-next/arch/x86/util/unwind-libdw.o
CC /tmp/build/perf-tools-next/util/arm64-frame-pointer-unwind-support.o
CC /tmp/build/perf-tools-next/tests/dwarf-unwind.o
CC /tmp/build/perf-tools-next/util/unwind-libdw.o
$
Should be in a separate patch, but tired now, so also adding a message
about the need to use LIBUNWIND=1 in the output when its not available,
so done here as well.
So, now when the devel files are not available we get:
$ make -k LIBUNWIND=1 CORESIGHT=1 O=/tmp/build/$(basename $PWD)/ -C tools/perf install-bin |& grep unwind && ldd ~/bin/perf | grep unwind
Makefile.config:653: No libunwind found. Please install libunwind-dev[el] >= 1.1 and/or set LIBUNWIND_DIR and set LIBUNWIND=1 in the make command line as it is opt-in now
... libunwind: [ OFF ]
$
Fixes: 13e17c9ff4 ("perf build: Make libunwind opt-in rather than opt-out")
Reported-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
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: https://lore.kernel.org/r/Z_AnsW9oJzFbhIFC@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
libcap isn't tested in the tools/build/feature/test-all.c fast path
feature detection process, so don't set it as available if test-all
manages to build.
There are other users of this feature detection mechanism, and they
explicitely ask for libcap to be tested, so are not affected by this
patch, for instance, with this patch in place:
$ make -C tools/bpf/bpftool/ clean
<SNIP>
make: Leaving directory '/home/acme/git/perf-tools-next/tools/bpf/bpftool'
⬢ [acme@toolbox perf-tools-next]$ make -C tools/bpf/bpftool/
make: Entering directory '/home/acme/git/perf-tools-next/tools/bpf/bpftool'
Auto-detecting system features:
... clang-bpf-co-re: [ on ]
... llvm: [ on ]
... libcap: [ on ]
... libbfd: [ on ]
... libelf-zstd: [ on ]
<SNIP>
LINK bpftool
make: Leaving directory '/home/acme/git/perf-tools-next/tools/bpf/bpftool'
$
$ sudo rpm -e libcap-devel
$ make -C tools/bpf/bpftool/
<SNIP>
make: Entering directory '/home/acme/git/perf-tools-next/tools/bpf/bpftool'
Auto-detecting system features:
... clang-bpf-co-re: [ on ]
... llvm: [ on ]
... libcap: [ OFF ]
... libbfd: [ on ]
... libelf-zstd: [ on ]
$
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Quentin Monnet <qmo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20241211224509.797827-3-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The tools/build/feature/test-all.c works in conjunction with the
tools/build/Makefile.feature FEATURE_TESTS_BASIC and FEATURE_TESTS_EXTRA
contents, so that if test-all.c manages to be built, we go on and
iterate all entries in FEATURE_TESTS_BASIC + FEATURE_TESTS_EXTRA setting
them to 1.
To test this:
$ rm -rf /tmp/b ; mkdir /tmp/b ; make -C tools/perf O=/tmp/b feature-dump
$ cat /tmp/b/feature/test-all.make.output
$ ldd /tmp/b/feature/test-all.bin
linux-vdso.so.1 (0x00007f2a47a67000)
libdw.so.1 => /lib64/libdw.so.1 (0x00007f2a477cf000)
libpython3.12.so.1.0 => /lib64/libpython3.12.so.1.0 (0x00007f2a471fe000)
libm.so.6 => /lib64/libm.so.6 (0x00007f2a4711a000)
libtraceevent.so.1 => /lib64/libtraceevent.so.1 (0x00007f2a470f2000)
libtracefs.so.1 => /lib64/libtracefs.so.1 (0x00007f2a470cb000)
libcrypto.so.3 => /lib64/libcrypto.so.3 (0x00007f2a46c1b000)
libz.so.1 => /lib64/libz.so.1 (0x00007f2a46bf8000)
libbabeltrace-ctf.so.1 => /lib64/libbabeltrace-ctf.so.1 (0x00007f2a46bad000)
libcapstone.so.5 => /lib64/libcapstone.so.5 (0x00007f2a464b8000)
libopencsd_c_api.so.1 => /lib64/libopencsd_c_api.so.1 (0x00007f2a464a8000)
libopencsd.so.1 => /lib64/libopencsd.so.1 (0x00007f2a46422000)
libelf.so.1 => /lib64/libelf.so.1 (0x00007f2a46406000)
libnuma.so.1 => /lib64/libnuma.so.1 (0x00007f2a463f6000)
libslang.so.2 => /lib64/libslang.so.2 (0x00007f2a46113000)
libperl.so.5.38 => /lib64/libperl.so.5.38 (0x00007f2a45d74000)
libc.so.6 => /lib64/libc.so.6 (0x00007f2a45b83000)
liblzma.so.5 => /lib64/liblzma.so.5 (0x00007f2a45b50000)
libzstd.so.1 => /lib64/libzstd.so.1 (0x00007f2a45a91000)
libbz2.so.1 => /lib64/libbz2.so.1 (0x00007f2a45a7b000)
/lib64/ld-linux-x86-64.so.2 (0x00007f2a47a69000)
libbabeltrace.so.1 => /lib64/libbabeltrace.so.1 (0x00007f2a45a6b000)
libpopt.so.0 => /lib64/libpopt.so.0 (0x00007f2a45a5b000)
libuuid.so.1 => /lib64/libuuid.so.1 (0x00007f2a45a51000)
libgmodule-2.0.so.0 => /lib64/libgmodule-2.0.so.0 (0x00007f2a45a4a000)
libglib-2.0.so.0 => /lib64/libglib-2.0.so.0 (0x00007f2a458fa000)
libstdc++.so.6 => /lib64/libstdc++.so.6 (0x00007f2a45696000)
libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f2a45668000)
libcrypt.so.2 => /lib64/libcrypt.so.2 (0x00007f2a45630000)
libpcre2-8.so.0 => /lib64/libpcre2-8.so.0 (0x00007f2a45590000)
$ head /tmp/b/FEATURE-DUMP
feature-backtrace=1
feature-libdw=1
feature-eventfd=1
feature-fortify-source=1
feature-get_current_dir_name=1
feature-gettid=1
feature-glibc=1
feature-libbfd=1
feature-libbfd-buildid=1
feature-libcap=1
$
There are inconsistencies that are being audited, as can be seen above
with the libcap case, that is not linked with test-all.bin nor is
present in test-all.c, so shouldn't be set as present. Further patches
are going to address those inconsistencies, but lets document this a bit
more to reduce the chances of this happening again.
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20241211224509.797827-2-acme@kernel.org
[ Fixed typo pointed out by Ian Rogers ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We have a tools/build/feature/test-all.c that has the most common set of
features that perf uses and are expected to have its development files
available when building perf.
When we made libwunwind opt-in we forgot to remove them from the list of
features that are assumed to be available when test-all.c builds, remove
them.
Before this patch:
$ rm -rf /tmp/b ; mkdir /tmp/b ; make -C tools/perf O=/tmp/b feature-dump ; grep feature-libunwind-aarch64= /tmp/b/FEATURE-DUMP
feature-libunwind-aarch64=1
$
Even tho this not being test built and those header files being
available:
$ head -5 tools/build/feature/test-libunwind-aarch64.c
// SPDX-License-Identifier: GPL-2.0
#include <libunwind-aarch64.h>
#include <stdlib.h>
extern int UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as,
$
After this patch:
$ grep feature-libunwind- /tmp/b/FEATURE-DUMP
$
Now an audit on what is being enabled when test-all.c builds will be
performed.
Fixes: 176c9d1e6a ("tools features: Don't check for libunwind devel files by default")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf tools updates from Namhyung Kim:
"perf record:
- Enable leader sampling for inherited task events. It was supported
only for system-wide events but the kernel started to support such
a setup since v6.12.
This is to reduce the number of PMU interrupts. The samples of the
leader event will contain counts of other events and no samples
will be generated for the other member events.
$ perf record -e '{cycles,instructions}:S' ${MYPROG}
perf report:
- Fix --branch-history option to display more branch-related
information like prediction, abort and cycles which is available
on Intel machines.
$ perf record -bg -- perf test -w brstack
$ perf report --branch-history
...
#
# Overhead Source:Line Symbol Shared Object Predicted Abort Cycles IPC [IPC Coverage]
# ........ ........................ .............. .................... ......... ..... ...... ....................
#
8.17% copy_page_64.S:19 [k] copy_page [kernel.kallsyms] 50.0% 0 5 - -
|
---xas_load xarray.h:171
|
|--5.68%--xas_load xarray.c:245 (cycles:1)
| xas_load xarray.c:242
| xas_load xarray.h:1260 (cycles:1)
| xas_descend xarray.c:146
| xas_load xarray.c:244 (cycles:2)
| xas_load xarray.c:245
| xas_descend xarray.c:218 (cycles:10)
...
perf stat:
- Add HWMON PMU support.
The HWMON provides various system information like CPU/GPU
temperature, fan speed and so on. Expose them as PMU events so that
users can see the values using perf stat commands.
$ perf stat -e temp_cpu,fan1 true
Performance counter stats for 'true':
60.00 'C temp_cpu
0 rpm fan1
0.000745382 seconds time elapsed
0.000883000 seconds user
0.000000000 seconds sys
- Display metric threshold in JSON output.
Some metrics define thresholds to classify value ranges. It used to
be in a different color but it won't work for JSON.
Add "metric-threshold" field to the JSON that can be one of "good",
"less good", "nearly bad" and "bad".
# perf stat -a -M TopdownL1 -j true
{"counter-value" : "18693525.000000", "unit" : "", "event" : "TOPDOWN.SLOTS", "event-runtime" : 5552708, "pcnt-running" : 100.00, "metric-value" : "43.226002", "metric-unit" : "% tma_backend_bound", "metric-threshold" : "bad"}
{"metric-value" : "29.212267", "metric-unit" : "% tma_frontend_bound", "metric-threshold" : "bad"}
{"metric-value" : "7.138972", "metric-unit" : "% tma_bad_speculation", "metric-threshold" : "good"}
{"metric-value" : "20.422759", "metric-unit" : "% tma_retiring", "metric-threshold" : "good"}
{"counter-value" : "3817732.000000", "unit" : "", "event" : "topdown-retiring", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
{"counter-value" : "5472824.000000", "unit" : "", "event" : "topdown-fe-bound", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
{"counter-value" : "7984780.000000", "unit" : "", "event" : "topdown-be-bound", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
{"counter-value" : "1418181.000000", "unit" : "", "event" : "topdown-bad-spec", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
...
perf sched:
- Add -P/--pre-migrations option for 'timehist' sub-command to track
time a task waited on a run-queue before migrating to a different
CPU.
$ perf sched timehist -P
time cpu task name wait time sch delay run time pre-mig time
[tid/pid] (msec) (msec) (msec) (msec)
--------------- ------ ------------------------------ --------- --------- --------- ---------
585940.535527 [0000] perf[584885] 0.000 0.000 0.000 0.000
585940.535535 [0000] migration/0[20] 0.000 0.002 0.008 0.000
585940.535559 [0001] perf[584885] 0.000 0.000 0.000 0.000
585940.535563 [0001] migration/1[25] 0.000 0.001 0.004 0.000
585940.535678 [0002] perf[584885] 0.000 0.000 0.000 0.000
585940.535686 [0002] migration/2[31] 0.000 0.002 0.008 0.000
585940.535905 [0001] <idle> 0.000 0.000 0.342 0.000
585940.535938 [0003] perf[584885] 0.000 0.000 0.000 0.000
585940.537048 [0001] sleep[584886] 0.000 0.019 1.142 0.001
585940.537749 [0002] <idle> 0.000 0.000 2.062 0.000
...
Build:
- Make libunwind opt-in (LIBUNWIND=1) rather than opt-out.
The perf tools are generally built with libelf and libdw which has
unwinder functionality. The libunwind support predates it and no
need to have duplicate unwinders by default.
- Rename NO_DWARF=1 build option to NO_LIBDW=1 in order to clarify
it's using libdw for handling DWARF information.
Internals:
- Do not set exclude_guest bit in the perf_event_attr by default.
This was causing a trouble in AMD IBS PMU as it doesn't support the
bit. The bit will be set when it's needed later by the fallback
logic. Also update the missing feature detection logic to make sure
not clear supported bits unnecessarily.
- Run perf test in parallel by default and mark flaky tests
"exclusive" to run them serially at the end. Some test numbers are
changed but the test can complete in less than half the time.
JSON vendor events:
- Add AMD Zen 5 events and metrics.
- Add i.MX91 and i.MX95 DDR metrics
- Fix HiSilicon HIP08 Topdown metric name.
- Support compat events on PowerPC"
* tag 'perf-tools-for-v6.13-2024-11-24' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (232 commits)
perf tests: Fix hwmon parsing with PMU name test
perf hwmon_pmu: Ensure hwmon key union is zeroed before use
perf tests hwmon_pmu: Remove double evlist__delete()
perf/test: fix perf ftrace test on s390
perf bpf-filter: Return -ENOMEM directly when pfi allocation fails
perf test: Correct hwmon test PMU detection
perf: Remove unused del_perf_probe_events()
perf pmu: Move pmu_metrics_table__find and remove ARM override
perf jevents: Add map_for_cpu()
perf header: Pass a perf_cpu rather than a PMU to get_cpuid_str
perf header: Avoid transitive PMU includes
perf arm64 header: Use cpu argument in get_cpuid
perf header: Refactor get_cpuid to take a CPU for ARM
perf header: Move is_cpu_online to numa bench
perf jevents: fix breakage when do perf stat on system metric
perf test: Add missing __exit calls in tool/hwmon tests
perf tests: Make leader sampling test work without branch event
perf util: Remove kernel version deadcode
perf test shell trace_exit_race: Use --no-comm to avoid cases where COMM isn't resolved
perf test shell trace_exit_race: Show what went wrong in verbose mode
...
In addition to the existing support for libbfd and calling out to
an external addr2line command, add support for using libllvm directly.
This is both faster than libbfd, and can be enabled in distro builds
(the LLVM license has an explicit provision for GPLv2 compatibility).
Thus, it is set as the primary choice if available.
As an example, running 'perf report' on a medium-size profile with
DWARF-based backtraces took 58 seconds with LLVM, 78 seconds with
libbfd, 153 seconds with external llvm-addr2line, and I got tired and
aborted the test after waiting for 55 minutes with external bfd
addr2line (which is the default for perf as compiled by distributions
today).
Evidently, for this case, the bfd addr2line process needs 18 seconds (on
a 5.2 GHz Zen 3) to load the .debug ELF in question, hits the 1-second
timeout and gets killed during initialization, getting restarted anew
every time. Having an in-process addr2line makes this much more robust.
As future extensions, libllvm can be used in many other places where
we currently use libbfd or other libraries:
- Symbol enumeration (in particular, for PE binaries).
- Demangling (including non-Itanium demangling, e.g. Microsoft
or Rust).
- Disassembling (perf annotate).
However, these are much less pressing; most people don't profile PE
binaries, and perf has non-bfd paths for ELF. The same with demangling;
the default _cxa_demangle path works fine for most users, and while bfd
objdump can be slow on large binaries, it is possible to use
--objdump=llvm-objdump to get the speed benefits. (It appears
LLVM-based demangling is very simple, should we want that.)
Tested with LLVM 14, 15, 16, 18 and 19. For some reason, LLVM 12 was not
correctly detected using feature_check, and thus was not tested.
Committer notes:
Added the name and a __maybe_unused to address:
1 13.50 almalinux:8 : FAIL gcc version 8.5.0 20210514 (Red Hat 8.5.0-22) (GCC)
util/srcline.c: In function 'dso__free_a2l':
util/srcline.c:184:20: error: parameter name omitted
void dso__free_a2l(struct dso *)
^~~~~~~~~~~~
make[3]: *** [/git/perf-6.11.0-rc3/tools/build/Makefile.build:158: util] Error 2
Signed-off-by: Steinar H. Gunderson <sesse@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20240803152008.2818485-1-sesse@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
During the transition to libbpf 1.0 some functions that perf used were
deprecated and finally removed from libbpf, so bpf_program__set_insns()
was introduced for perf to continue to use its bpf loader.
But when build with LIBBPF_DYNAMIC=1 we now need to check if that
function is available so that perf can build with older libbpf versions,
even if the end result is emitting a warning to the user that the use
of the perf BPF loader requires a newer libbpf, since bpf_program__set_insns()
touches libbpf objects internal state.
This affects only 'perf trace' when using bpf C code or pre-compiled
bytecode as an event.
Noticed on RHEL9, that has libbpf 0.7.0, where bpf_program__set_insns()
isn't available.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Sometimes, features are simply different flavors of another feature, to
properly detect the exact dependencies needed by different Linux
distributions.
For example, libbfd has three flavors: libbfd if the distro does not
require any additional dependency; libbfd-liberty if it requires libiberty;
libbfd-liberty-z if it requires libiberty and libz.
It might not be clear to the user whether a feature has been successfully
detected or not, given that some of its flavors will be set to OFF, others
to ON.
Instead, display only the feature main flavor if not in verbose mode
(VF != 1), and set it to ON if at least one of its flavors has been
successfully detected (logical OR), OFF otherwise. Omit the other flavors.
Accomplish that by declaring a FEATURE_GROUP_MEMBERS-<feature main flavor>
variable, with the list of the other flavors as variable value. For now, do
it just for libbfd.
In verbose mode, of if no group is defined for a feature, show the feature
detection result as before.
Committer testing:
Collecting the output from:
$ make -C tools/bpf/bpftool/ clean
$ make -C tools/bpf/bpftool/ |& grep "Auto-detecting system features" -A10
$ diff -u before after
--- before 2022-08-18 10:06:40.422086966 -0300
+++ after 2022-08-18 10:07:59.202138282 -0300
@@ -1,6 +1,4 @@
Auto-detecting system features:
... libbfd: [ on ]
-... libbfd-liberty: [ on ]
-... libbfd-liberty-z: [ on ]
... libcap: [ on ]
... clang-bpf-co-re: [ on ]
$
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220818120957.319995-3-roberto.sassu@huaweicloud.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As the first eval expansion is used only to generate Makefile statements,
messages should not be displayed at this stage, as for example conditional
expressions are not evaluated.
It can be seen for example in the output of feature detection for bpftool,
where the number of detected features does not change, despite turning on
the verbose mode (VF = 1) and there are additional features to display.
Fix this issue by escaping the $ before $(info) statements, to ensure that
messages are printed only when the function containing them is actually
executed, and not when it is expanded.
In addition, move the $(info) statement out of feature_print_status, due to
the fact that is called both inside and outside an eval context, and place
it to the caller so that the $ can be escaped when necessary. For symmetry,
move the $(info) statement also out of feature_print_text, and place it to
the caller.
Force the TMP variable evaluation in verbose mode, to display the features
in FEATURE_TESTS that are not in FEATURE_DISPLAY.
Reorder perf feature detection messages (first non-verbose, then verbose
ones) by moving the call to feature_display_entries earlier, before the VF
environment variable check.
Also, remove the newline from that function, as perf might display
additional messages. Move the newline to perf Makefile, and display another
one if displaying the detection result is not deferred as in the case of
bpftool.
Committer testing:
Collecting the output from:
$ make VF=1 -C tools/bpf/bpftool/ |& grep "Auto-detecting system features" -A20
$ diff -u before after
--- before 2022-08-18 09:59:55.460529231 -0300
+++ after 2022-08-18 10:01:11.182517282 -0300
@@ -4,3 +4,5 @@
... libbfd-liberty-z: [ on ]
... libcap: [ on ]
... clang-bpf-co-re: [ on ]
+... disassembler-four-args: [ on ]
+... disassembler-init-styled: [ OFF ]
$
Fixes: 0afc5cad38 ("perf build: Separate feature make support into config/Makefile.feature")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: bpf@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/r/20220818120957.319995-1-roberto.sassu@huaweicloud.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Avi Kivity reported a problem where the __weak
btf__load_from_kernel_by_id() in tools/perf/util/bpf-event.c was being
used and it called btf__get_from_id() in tools/lib/bpf/btf.c that in
turn called back to btf__load_from_kernel_by_id(), resulting in an
endless loop.
Fix this by adding a feature test to check if
btf__load_from_kernel_by_id() is available when building perf with
LIBBPF_DYNAMIC=1, and if not then provide the fallback to the old
btf__get_from_id(), that doesn't call back to btf__load_from_kernel_by_id()
since at that time it didn't exist at all.
Tested on Fedora 35 where we have libbpf-devel 0.4.0 with LIBBPF_DYNAMIC
where we don't have btf__load_from_kernel_by_id() and thus its feature
test fail, not defining HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID:
$ cat /tmp/build/perf-urgent/feature/test-libbpf-btf__load_from_kernel_by_id.make.output
test-libbpf-btf__load_from_kernel_by_id.c: In function ‘main’:
test-libbpf-btf__load_from_kernel_by_id.c:6:16: error: implicit declaration of function ‘btf__load_from_kernel_by_id’ [-Werror=implicit-function-declaration]
6 | return btf__load_from_kernel_by_id(20151128, NULL);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
$
$ nm /tmp/build/perf-urgent/perf | grep btf__load_from_kernel_by_id
00000000005ba180 T btf__load_from_kernel_by_id
$
$ objdump --disassemble=btf__load_from_kernel_by_id -S /tmp/build/perf-urgent/perf
/tmp/build/perf-urgent/perf: file format elf64-x86-64
<SNIP>
00000000005ba180 <btf__load_from_kernel_by_id>:
#include "record.h"
#include "util/synthetic-events.h"
#ifndef HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID
struct btf *btf__load_from_kernel_by_id(__u32 id)
{
5ba180: 55 push %rbp
5ba181: 48 89 e5 mov %rsp,%rbp
5ba184: 48 83 ec 10 sub $0x10,%rsp
5ba188: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax
5ba18f: 00 00
5ba191: 48 89 45 f8 mov %rax,-0x8(%rbp)
5ba195: 31 c0 xor %eax,%eax
struct btf *btf;
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
int err = btf__get_from_id(id, &btf);
5ba197: 48 8d 75 f0 lea -0x10(%rbp),%rsi
5ba19b: e8 a0 57 e5 ff call 40f940 <btf__get_from_id@plt>
5ba1a0: 89 c2 mov %eax,%edx
#pragma GCC diagnostic pop
return err ? ERR_PTR(err) : btf;
5ba1a2: 48 98 cltq
5ba1a4: 85 d2 test %edx,%edx
5ba1a6: 48 0f 44 45 f0 cmove -0x10(%rbp),%rax
}
<SNIP>
Fixes: 218e7b775d ("perf bpf: Provide a weak btf__load_from_kernel_by_id() for older libbpf versions")
Reported-by: Avi Kivity <avi@scylladb.com>
Link: https://lore.kernel.org/linux-perf-users/f0add43b-3de5-20c5-22c4-70aff4af959f@scylladb.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/linux-perf-users/YobjjFOblY4Xvwo7@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since 66dfdff03d ("perf tools: Add Python 3 support") we don't use
the tools/build/feature/test-libpython-version.c version in any Makefile
feature check:
$ find tools/ -type f | xargs grep feature-libpython-version
$
The only place where this was used was removed in 66dfdff03d:
- ifneq ($(feature-libpython-version), 1)
- $(warning Python 3 is not yet supported; please set)
- $(warning PYTHON and/or PYTHON_CONFIG appropriately.)
- $(warning If you also have Python 2 installed, then)
- $(warning try something like:)
- $(warning $(and ,))
- $(warning $(and ,) make PYTHON=python2)
- $(warning $(and ,))
- $(warning Otherwise, disable Python support entirely:)
- $(warning $(and ,))
- $(warning $(and ,) make NO_LIBPYTHON=1)
- $(warning $(and ,))
- $(error $(and ,))
- else
- LDFLAGS += $(PYTHON_EMBED_LDFLAGS)
- EXTLIBS += $(PYTHON_EMBED_LIBADD)
- LANG_BINDINGS += $(obj-perf)python/perf.so
- $(call detected,CONFIG_LIBPYTHON)
- endif
And nowadays we either build with PYTHON=python3 or just install the
python3 devel packages and perf will build against it.
But the leftover feature-libpython-version check made the fast path
feature detection to break in all cases except when python2 devel files
were installed:
$ rpm -qa | grep python.*devel
python3-devel-3.9.7-1.fc34.x86_64
$ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf ;
$ make -C tools/perf O=/tmp/build/perf install-bin
make: Entering directory '/var/home/acme/git/perf/tools/perf'
BUILD: Doing 'make -j32' parallel build
HOSTCC /tmp/build/perf/fixdep.o
<SNIP>
$ cat /tmp/build/perf/feature/test-all.make.output
In file included from test-all.c:18:
test-libpython-version.c:5:10: error: #error
5 | #error
| ^~~~~
$ ldd ~/bin/perf | grep python
libpython3.9.so.1.0 => /lib64/libpython3.9.so.1.0 (0x00007fda6dbcf000)
$
As python3 is the norm these days, fix this by just removing the unused
feature-libpython-version feature check, making the test-all fast path
to work with the common case.
With this:
$ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf ;
$ make -C tools/perf O=/tmp/build/perf install-bin |& head
make: Entering directory '/var/home/acme/git/perf/tools/perf'
BUILD: Doing 'make -j32' parallel build
HOSTCC /tmp/build/perf/fixdep.o
HOSTLD /tmp/build/perf/fixdep-in.o
LINK /tmp/build/perf/fixdep
Auto-detecting system features:
... dwarf: [ on ]
... dwarf_getlocations: [ on ]
... glibc: [ on ]
$ ldd ~/bin/perf | grep python
libpython3.9.so.1.0 => /lib64/libpython3.9.so.1.0 (0x00007f58800b0000)
$ cat /tmp/build/perf/feature/test-all.make.output
$
Reviewed-by: James Clark <james.clark@arm.com>
Fixes: 66dfdff03d ("perf tools: Add Python 3 support")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jaroslav Škarvada <jskarvad@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/YaYmeeC6CS2b8OSz@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
By setting FEATURE_DISPLAY_DEFERRED=1 a tool may ask for the printout
of the detected features in tools/build/Makefile.feature to be done
later adter extra feature checks are done that are tool specific.
The perf tool will do it via its tools/perf/Makefile.config, as it
performs such extra feature checks.
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently we support only static linking with kernel's libtraceevent
(tools/lib/traceevent). This patch adds libtraceevent package detection
and support to link perf with it dynamically.
The libtraceevent package status is displayed with:
$ make VF=1 LIBTRACEEVENT_DYNAMIC=1
...
... libtraceevent: [ on ]
Default behavior remains the same (static linking).
Committer testing:
$ make LIBTRACEEVENT_DYNAMIC=1 VF=1 O=/tmp/build/perf -C tools/perf install-bin |& grep traceevent
Makefile.config:1090: *** Error: No libtraceevent devel library found, please install libtraceevent-devel. Stop.
$
Signed-off-by: Michael Petlan <mpetlan@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
LPU-Reference: 20210428092023.4009-1-mpetlan@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
