Complete multi-prog sections and multi sub-prog support in libbpf by properly
adjusting .BTF.ext's line and function information. Mark exposed
btf_ext__reloc_func_info() and btf_ext__reloc_func_info() APIs as deprecated.
These APIs have simplistic assumption that all sub-programs are going to be
appended to all main BPF programs, which doesn't hold in real life. It's
unlikely there are any users of this API, as it's very libbpf
internals-specific.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200903203542.15944-6-andriin@fb.com
This patch implements general and correct logic for bpf-to-bpf sub-program
calls. Only sub-programs used (called into) from entry-point (main) BPF
program are going to be appended at the end of main BPF program. This ensures
that BPF verifier won't encounter any dead code due to copying unreferenced
sub-program. This change means that each entry-point (main) BPF program might
have a different set of sub-programs appended to it and potentially in
different order. This has implications on how sub-program call relocations
need to be handled, described below.
All relocations are now split into two categores: data references (maps and
global variables) and code references (sub-program calls). This distinction is
important because data references need to be relocated just once per each BPF
program and sub-program. These relocation are agnostic to instruction
locations, because they are not code-relative and they are relocating against
static targets (maps, variables with fixes offsets, etc).
Sub-program RELO_CALL relocations, on the other hand, are highly-dependent on
code position, because they are recorded as instruction-relative offset. So
BPF sub-programs (those that do calls into other sub-programs) can't be
relocated once, they need to be relocated each time such a sub-program is
appended at the end of the main entry-point BPF program. As mentioned above,
each main BPF program might have different subset and differen order of
sub-programs, so call relocations can't be done just once. Splitting data
reference and calls relocations as described above allows to do this
efficiently and cleanly.
bpf_object__find_program_by_name() will now ignore non-entry BPF programs.
Previously one could have looked up '.text' fake BPF program, but the
existence of such BPF program was always an implementation detail and you
can't do much useful with it. Now, though, all non-entry sub-programs get
their own BPF program with name corresponding to a function name, so there is
no more '.text' name for BPF program. This means there is no regression,
effectively, w.r.t. API behavior. But this is important aspect to highlight,
because it's going to be critical once libbpf implements static linking of BPF
programs. Non-entry static BPF programs will be allowed to have conflicting
names, but global and main-entry BPF program names should be unique. Just like
with normal user-space linking process. So it's important to restrict this
aspect right now, keep static and non-entry functions as internal
implementation details, and not have to deal with regressions in behavior
later.
This patch leaves .BTF.ext adjustment as is until next patch.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200903203542.15944-5-andriin@fb.com
Fix up CO-RE relocation code to handle relocations against ELF sections
containing multiple BPF programs. This requires lookup of a BPF program by its
section name and instruction index it contains. While it could have been done
as a simple loop, it could run into performance issues pretty quickly, as
number of CO-RE relocations can be quite large in real-world applications, and
each CO-RE relocation incurs BPF program look up now. So instead of simple
loop, implement a binary search by section name + insn offset.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200903203542.15944-4-andriin@fb.com
Teach libbpf how to parse code sections into potentially multiple bpf_program
instances, based on ELF FUNC symbols. Each BPF program will keep track of its
position within containing ELF section for translating section instruction
offsets into program instruction offsets: regardless of BPF program's location
in ELF section, it's first instruction is always at local instruction offset
0, so when libbpf is working with relocations (which use section-based
instruction offsets) this is critical to make proper translations.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200903203542.15944-3-andriin@fb.com
Before changing this it's a bit confusing to read test output:
raw csum_off with bad offset (fails)
./psock_snd: write: Invalid argument
Change "fails" in the test case description to "expected to fail", so
that the test output can be more understandable.
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To address these errors found when cross building from x86_64 to MIPS
little endian 32-bit:
CC /tmp/build/perf/util/parse-events-bison.o
util/parse-events.y: In function 'parse_events_parse':
util/parse-events.y:514:6: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
514 | (void *) $2, $6, $4);
| ^
util/parse-events.y:531:7: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
531 | (void *) $2, NULL, $4)) {
| ^
util/parse-events.y:547:6: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
547 | (void *) $2, $4, 0);
| ^
util/parse-events.y:564:7: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
564 | (void *) $2, NULL, 0)) {
| ^
Fixes: cabbf26821 ("perf parse: Before yyabort-ing free components")
Cc: Adrian Hunter <adrian.hunter@intel.com>
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: Ian Rogers <irogers@google.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For compatibility reasons, Glibc off_t is a 32-bit type on 32-bit x86
unless _FILE_OFFSET_BITS=64 is defined. Add this define, as otherwise
reading MSRs with index 0x80000000 and above attempts a pread with a
negative offset, which fails.
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Tested-by: Liwei Song <liwei.song@windriver.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Family 19h processors have the same RAPL (Running average power limit)
hardware register interface as Family 17h processors.
Change the family checks to succeed for Family 17h and above to enable
core and package energy measurement on Family 19h machines.
Also update the TDP to the largest found at the bottom of the page at
amd.com->processors->servers->epyc->2nd-gen-epyc, i.e., the EPYC 7H12.
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
Jacobsville doesn't have Package C2 and C6. Also
Core and DRAM RAPL are not available. Adjust output
accordingly.
Signed-off-by: Antti Laakso <antti.laakso@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The column already present called GFXMHz reads from gt_cur_freq_mhz,
which represents the GT frequency that was requested, but power
management might not be able to do that. So the new column will display
what the actual frequency GT is running at.
Signed-off-by: Rafael Antognolli <rafael.antognolli@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
I've encountered an issue with x86_energy_perf_policy. If I run it on a
machine that I'm told is a qemu-kvm virtual machine running inside a
privileged container, I get the following error:
x86_energy_perf_policy: /dev/cpu/0/msr offset 0x1ad read failed: Input/output error
I get the same error in a Digital Ocean droplet, so that might be a
similar environment.
I created the following patch which is intended to give a more
user-friendly message. It's based on a patch for turbostat from Prarit
Bhargava that was posted some time ago. The patch is "[v2] turbostat:
Running on virtual machine is not supported" [1].
Given my limited knowledge of the topic, I can't say with confidence
that this is the right solution, though (that's why this is not an
official patch submission). Also, I'm not sure what the convention with
exit codes is in this tool. Also, instead of the error message, perhaps
the tool should just not print anything in this case, which is how it
behaves in a "regular" VM?
[1] https://patchwork.kernel.org/patch/9868587/
Signed-off-by: Ondřej Lysoněk <olysonek@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Like we skip PC3 and PC6 columns when the package C-state limit
disables them, skip PC8/PC9/CP10 under analogous conditions.
Reported-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
turbostat formatting is broken with ACPI CST for enumeration. The
problem is that the CX_ACPI% is eight characters long which does not
work with tab formatting. One simple solution is to remove the underbar
from the state name such that C1_ACPI will be displayed as C1ACPI.
Signed-off-by: David Arcari <darcari@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Disabling cpu 0 results in an error
turbostat: /sys/devices/system/cpu/cpu0/topology/thread_siblings: open failed: No such file or directory
Use sched_getcpu() instead of a hardcoded cpu 0 to get the max cpu number.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Since the RAPL Joule Counter is 32 bit, turbostat would
only print a *star* instead of printing the actual energy
consumed to indicate the overflow due to long duration.
This does not meet the requirement from servers as the
sampling time of turbostat is usually very long on servers.
So maintain a set of MSR buffer, and update them
periodically before the 32bit MSR register is wrapped round,
so as to avoid the overflow.
The idea is similar to the implementation of ktime_get():
Periodical MSR timer:
total_rapl_sum += (current_rapl_msr - last_rapl_msr);
Using get_msr_sum() to get the accumulated RAPL:
return (current_rapl_msr - last_rapl_msr) + total_rapl_sum;
The accumulated RAPL mechanism will be turned on in next patch.
Originally-by: Aaron Lu <aaron.lwe@gmail.com>
Reviewed-by: Doug Smythies <dsmythies@telus.net>
Tested-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Change the energy variable from 32bit to 64bit,
so that it can record long time duration.
After this conversion, adjust the DELTA_WRAP32() accordingly.
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
If the --quiet option is not used, turbostat prints a useful system
configuration header during startup.
But inclusion of idle system configuration information in this header
is currently a function of inclusion in the columns chosen to be displayed.
Always list this idle system configuration.
Signed-off-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Len Brown <len.brown@intel.com>
Users are puzzled when they use tuned performance and all their
C-states vanish. Dump /dev/cpu_dma_latency and state
whether the value is default, or constraining,
to explain this situation.
Signed-off-by: Len Brown <len.brown@intel.com>
Current LKMM documentation assumes that the reader already understands
concurrency in the Linux kernel, which won't necessarily always be the
case. This commit supplies a simple.txt file that provides a starting
point for someone who is new to concurrency in the Linux kernel.
That said, this file might also useful as a reminder to experienced
developers of simpler approaches to dealing with concurrency.
Link: Link: https://lwn.net/Articles/827180/
[ paulmck: Apply feedback from Joel Fernandes. ]
Co-developed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Co-developed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The current LKMM documentation says very little about litmus tests, and
worse yet directs people to the herd7 documentation for more information.
Now, the herd7 documentation is quite voluminous and educational,
but it is intended for people creating and modifying memory models,
not those attempting to use them.
This commit therefore updates README and creates a litmus-tests.txt
file that gives an overview of litmus-test format and describes ways of
modeling various special cases, illustrated with numerous examples.
[ paulmck: Add Alan Stern feedback. ]
[ paulmck: Apply Dave Chinner feedback. ]
[ paulmck: Apply Andrii Nakryiko feedback. ]
[ paulmck: Apply Johannes Weiner feedback. ]
Link: https://lwn.net/Articles/827180/
Reported-by: Dave Chinner <david@fromorbit.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The expand_to_next_prime() and next_prime_number() functions have moved
from lib/prime_numbers.c to lib/math/prime_numbers.c, so this commit
updates recipes.txt to reflect this change.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
in mptcp_connect, 's' selects IPPROTO_MPTCP / IPPROTO_TCP as the value of
'protocol' in socket(), and 'm' switches between different send / receive
modes. Fix die_usage(): swap 'm' and 's' and add missing 'sendfile' mode.
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Modified existing bpf_iter_test_file.c program to check whether
all accessed files from the main thread or not.
Modified existing bpf_iter_test_file program to check
whether all accessed files from the main thread or not.
$ ./test_progs -n 4
...
#4/7 task_file:OK
...
#4 bpf_iter:OK
Summary: 1/24 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200902023113.1672863-1-yhs@fb.com
Pull perf tools fixes from Arnaldo Carvalho de Melo:
- Fix infinite loop in the TUI for grouped events in 'perf top/record',
eg when using "perf top -e '{cycles,instructions,cache-misses}'".
- Fix segfault by skipping side-band event setup if HAVE_LIBBPF_SUPPORT
is not set.
- Fix synthesized branch stacks generated from CoreSight ETM trace and
Intel PT hardware traces.
- Fix error when synthesizing events from ARM SPE hardware trace.
- The SNOOPX and REMOTE offsets in the data_src bitmask in perf records
were were both 37, SNOOPX is 38, fix it.
- Fix use of CPU list with summary option in 'perf sched timehist'.
- Avoid an uninitialized read when using fake PMUs.
- Set perf_event_attr.exclude_guest=1 for user-space counting.
- Don't order events when doing a 'perf report -D' raw dump of
perf.data records.
- Set NULL sentinel in pmu_events table in "Parse and process metrics"
'perf test'
- Fix basic bpf filtering 'perf test' on s390x.
- Fix out of bounds array access in the 'perf stat' print_counters()
evlist method.
- Add mwait_idle_with_hints.constprop.0 to the list of idle symbols.
- Use %zd for size_t printf formats on 32-bit.
- Correct the help info of "perf record --no-bpf-event" option.
- Add entries for CoreSight and Arm SPE tooling to MAINTAINERS.
* tag 'perf-tools-fixes-for-v5.9-2020-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
perf report: Disable ordered_events for raw dump
perf tools: Correct SNOOPX field offset
perf intel-pt: Fix corrupt data after perf inject from
perf cs-etm: Fix corrupt data after perf inject from
perf top/report: Fix infinite loop in the TUI for grouped events
perf parse-events: Avoid an uninitialized read when using fake PMUs
perf stat: Fix out of bounds array access in the print_counters() evlist method
perf test: Set NULL sentinel in pmu_events table in "Parse and process metrics" test
perf parse-events: Set exclude_guest=1 for user-space counting
perf record: Correct the help info of option "--no-bpf-event"
perf tools: Use %zd for size_t printf formats on 32-bit
MAINTAINERS: Add entries for CoreSight and Arm SPE tooling
perf: arm-spe: Fix check error when synthesizing events
perf symbols: Add mwait_idle_with_hints.constprop.0 to the list of idle symbols
perf top: Skip side-band event setup if HAVE_LIBBPF_SUPPORT is not set
perf sched timehist: Fix use of CPU list with summary option
perf test: Fix basic bpf filtering test
Implementation of ORC requires some definitions that are currently
provided by the target architecture headers. Do not depend on these
definitions when the orc subcommand is not implemented.
This avoid requiring arches with no orc implementation to provide dummy
orc definitions.
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Orc generation is only done for text sections, but some instructions
can be found in non-text sections (e.g. .discard.text sections).
Skip setting their orc sections since their whole sections will be
skipped for orc generation.
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Now that the objtool_file can be obtained outside of the check function,
orc generation builtin no longer requires check to explicitly call its
orc related functions.
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Structure objtool_file can be used by different subcommands. In fact
it already is, by check and orc.
Provide a function that allows to initialize objtool_file, that builtin
can call, without relying on check to do the correct setup for them and
explicitly hand the objtool_file to them.
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Daniel Borkmann says:
====================
pull-request: bpf-next 2020-09-01
The following pull-request contains BPF updates for your *net-next* tree.
There are two small conflicts when pulling, resolve as follows:
1) Merge conflict in tools/lib/bpf/libbpf.c between 88a8212028 ("libbpf: Factor
out common ELF operations and improve logging") in bpf-next and 1e891e513e
("libbpf: Fix map index used in error message") in net-next. Resolve by taking
the hunk in bpf-next:
[...]
scn = elf_sec_by_idx(obj, obj->efile.btf_maps_shndx);
data = elf_sec_data(obj, scn);
if (!scn || !data) {
pr_warn("elf: failed to get %s map definitions for %s\n",
MAPS_ELF_SEC, obj->path);
return -EINVAL;
}
[...]
2) Merge conflict in drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c between
9647c57b11 ("xsk: i40e: ice: ixgbe: mlx5: Test for dma_need_sync earlier for
better performance") in bpf-next and e20f0dbf20 ("net/mlx5e: RX, Add a prefetch
command for small L1_CACHE_BYTES") in net-next. Resolve the two locations by retaining
net_prefetch() and taking xsk_buff_dma_sync_for_cpu() from bpf-next. Should look like:
[...]
xdp_set_data_meta_invalid(xdp);
xsk_buff_dma_sync_for_cpu(xdp, rq->xsk_pool);
net_prefetch(xdp->data);
[...]
We've added 133 non-merge commits during the last 14 day(s) which contain
a total of 246 files changed, 13832 insertions(+), 3105 deletions(-).
The main changes are:
1) Initial support for sleepable BPF programs along with bpf_copy_from_user() helper
for tracing to reliably access user memory, from Alexei Starovoitov.
2) Add BPF infra for writing and parsing TCP header options, from Martin KaFai Lau.
3) bpf_d_path() helper for returning full path for given 'struct path', from Jiri Olsa.
4) AF_XDP support for shared umems between devices and queues, from Magnus Karlsson.
5) Initial prep work for full BPF-to-BPF call support in libbpf, from Andrii Nakryiko.
6) Generalize bpf_sk_storage map & add local storage for inodes, from KP Singh.
7) Implement sockmap/hash updates from BPF context, from Lorenz Bauer.
8) BPF xor verification for scalar types & add BPF link iterator, from Yonghong Song.
9) Use target's prog type for BPF_PROG_TYPE_EXT prog verification, from Udip Pant.
10) Rework BPF tracing samples to use libbpf loader, from Daniel T. Lee.
11) Fix xdpsock sample to really cycle through all buffers, from Weqaar Janjua.
12) Improve type safety for tun/veth XDP frame handling, from Maciej Żenczykowski.
13) Various smaller cleanups and improvements all over the place.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The new resolve_btfids tool did not clean up the feature detection folder
on 'make clean', and also was not called properly from the clean rule in
tools/make/ folder on its 'make clean'. This lead to stale objects being
left around, which could cause feature detection to fail on subsequent
builds.
Fixes: fbbb68de80 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/bpf/20200901144343.179552-1-toke@redhat.com
For a while we need to have a dummy event for doing things like
receiving PERF_RECORD_COMM, PERF_RECORD_EXEC, etc for threads being
created and dying while we synthesize the pre-existing ones at tool
start.
This 'dummy' event is needed for keeping track of thread lifetime events
early in the session but are uninteresting otherwise, i.e. no need to
have it in a initial events menu for the non-grouped case, i.e. for:
# perf top -e cycles,instructions
or even for plain:
# perf top
When 'cycles' and that 'dummy' event are in place.
The code to remove that 'dummy' event ended up creating an endless loop
for the grouped case, i.e.:
# perf top -e '{cycles,instructions}'
Fix it.
Fixes: bee9ca1c8a ("perf report TUI: Remove needless 'dummy' event from menu")
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>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
