Metrics may generate many particularly uncore event references. The
resulting event string may then be >32kb. The parse events lex is
using "%option reject" which stores backtracking state in a buffer
sized at roughtly 30kb. If the event string is larger than this then a
buffer overflow and typically a crash happens.
The need for "%option reject" was for BPF events which were removed in
commit 3d6dfae889 ("perf parse-events: Remove BPF event
support"). As "%option reject" is both a memory and performance cost
let's remove it and fix the parsing case for event strings being over
~30kb.
Whilst cleaning up "%option reject" make the header files accurately
reflect functions used in the code and tidy up not requiring yywrap.
Measuring on the "PMU JSON event tests" a modest reduction of 0.41%
user time and 0.27% max resident size was observed. More importantly
this change fixes parsing large metrics and event strings.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For the sake of Intel topdown events commit 9eac5612da ("perf
stat: Don't skip failing group events") changed 'perf stat' error
handling making it so that more errors were fatal and didn't report
"<not supported>" events. The change outside of topdown events was
unintentional.
The notion of "fatal" error handling was introduced in commit
e0e6a6ca3a ("perf stat: Factor out open error handling") and
refined in commits like commit cb5ef60067 ("perf stat: Error out
unsupported group leader immediately") to be an approach for avoiding
later assertion failures in the code base.
This change fixes those issues and removes the notion of a fatal error
on an event. If all events fail to open then a fatal error occurs with
the previous fatal error message. This seems to best match the notion of
supported events and allowing some errors not to stop 'perf stat', while
allowing the truly fatal no event case to terminate the tool early.
The evsel->errored flag is only used in the stat code but always just
meaning !evsel->supported although there is a comment about it being
sticky. Force all evsels to be supported in evsel__init and then clear
this when evsel__open fails. When an event is tried the supported is
set to true again. This simplifies the notion of whether an evsel is
broken.
In the get_group_fd code, fail to get a group fd when the evsel isn't
supported. If the leader isn't supported then it is also expected that
there is no group_fd as the leader will have been skipped. Therefore
change the BUG_ON test to be on supported rather than skippable. This
corrects the assertion errors that were the reason for the previous
fatal error handling.
Fixes: 9eac5612da ("perf stat: Don't skip failing group events")
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Chun-Tse Shao <ctshao@google.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.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>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Link: https://lore.kernel.org/r/20251002220727.1889799-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
After KVM supports PEBS for guest on Intel platforms
(https://lore.kernel.org/all/20220411101946.20262-1-likexu@tencent.com/),
host loses the capability to sample guest with PEBS since all PEBS related
MSRs are switched to guest value after vm-entry, like IA32_DS_AREA MSR is
switched to guest GVA at vm-entry. This would lead to "perf kvm record"
fails to sample guest on Intel platforms since "cycles:P" event is used to
sample guest by default as below case shows.
sudo perf kvm record -a
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.787 MB perf.data.guest ]
So to ensure guest record can be sampled successfully, use "cycles"
instead of "cycles:P" to sample guest record by default on Intel
platforms. With this patch, the guest record can be sampled
successfully.
sudo perf kvm record -a
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.783 MB perf.data.guest (23 samples) ]
Fixes: cf8e55fe50 ("KVM: x86/pmu: Expose CPUIDs feature bits PDCM, DS, DTES64")
Reported-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Like Xu <likexu@tencent.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When exploring building bpf_skel with GCC's BPF support, there was a
build failure because of bpf_core_field_exists vs the mem_hops bitfield:
```
In file included from util/bpf_skel/sample_filter.bpf.c:6:
util/bpf_skel/sample_filter.bpf.c: In function 'perf_get_sample':
tools/perf/libbpf/include/bpf/bpf_core_read.h:169:42: error: cannot take address of bit-field 'mem_hops'
169 | #define ___bpf_field_ref1(field) (&(field))
| ^
tools/perf/libbpf/include/bpf/bpf_helpers.h:222:29: note: in expansion of macro '___bpf_field_ref1'
222 | #define ___bpf_concat(a, b) a ## b
| ^
tools/perf/libbpf/include/bpf/bpf_helpers.h:225:29: note: in expansion of macro '___bpf_concat'
225 | #define ___bpf_apply(fn, n) ___bpf_concat(fn, n)
| ^~~~~~~~~~~~~
tools/perf/libbpf/include/bpf/bpf_core_read.h:173:9: note: in expansion of macro '___bpf_apply'
173 | ___bpf_apply(___bpf_field_ref, ___bpf_narg(args))(args)
| ^~~~~~~~~~~~
tools/perf/libbpf/include/bpf/bpf_core_read.h:188:39: note: in expansion of macro '___bpf_field_ref'
188 | __builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_EXISTS)
| ^~~~~~~~~~~~~~~~
util/bpf_skel/sample_filter.bpf.c:167:29: note: in expansion of macro 'bpf_core_field_exists'
167 | if (bpf_core_field_exists(data->mem_hops))
| ^~~~~~~~~~~~~~~~~~~~~
cc1: error: argument is not a field access
```
___bpf_field_ref1 was adapted for GCC in 12bbcf8e84
but the trick added for compatibility in 3a8b8fc317
isn't compatible with that as an address is used as an argument.
Workaround this by calling __builtin_preserve_field_info directly as the
bpf_core_field_exists macro does, but without the ___bpf_field_ref use.
Co-developed-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>
Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>
Signed-off-by: Sam James <sam@gentoo.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://gcc.gnu.org/PR121420
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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>
Don't open evsels on all CPUs, open them just on the CPUs they
support. This avoids opening say an e-core event on a p-core and
getting a failure - achieve this by getting rid of the "all_cpu_map".
In install_pe functions don't use the cpu_map_idx as a CPU number,
translate the cpu_map_idx, which is a dense index into the cpu_map
skipping holes at the beginning, to a proper CPU number.
Before:
```
$ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
Performance counter stats for 'system wide':
<not supported> cpu_atom/cycles/
566,270,672 cpu_core/cycles/
<not supported> cpu_atom/instructions/
572,792,836 cpu_core/instructions/ # 1.01 insn per cycle
1.001595384 seconds time elapsed
```
After:
```
$ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
Performance counter stats for 'system wide':
443,299,201 cpu_atom/cycles/
1,233,919,737 cpu_core/cycles/
213,634,112 cpu_atom/instructions/ # 0.48 insn per cycle
2,758,965,527 cpu_core/instructions/ # 2.24 insn per cycle
1.001699485 seconds time elapsed
```
Fixes: 7fac83aaf2 ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: bpf@vger.kernel.org
Cc: Gabriele Monaco <gmonaco@redhat.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Create samples from DTL entries for displaying in 'perf report'
and 'perf script'.
When the different PERF_RECORD_XX records are processed from perf
session, powerpc_vpadtl_process_event() will be invoked.
For each of the PERF_RECORD_XX record, compare the timestamp of perf
record with timestamp of top element in the auxtrace heap.
Process the auxtrace queue if the timestamp of element from heap is
lower than timestamp from entry in perf record.
Sometimes it could happen that one buffer is only partially processed.
if the timestamp of occurrence of another event is more than currently
processed element in the queue, it will move on to next perf record.
So keep track of position of buffer to continue processing next time.
Update the timestamp of the auxtrace heap with the timestamp of last
processed entry from the auxtrace buffer.
Generate perf sample for each entry in the dispatch trace log.
Fill in the sample details:
- sample ip is picked from srr0 field of dtl_entry
- sample cpu is picked from processor_id of dtl_entry
- sample id is from sample_id of powerpc_vpadtl
- cpumode is set to PERF_RECORD_MISC_KERNEL
- Additionally save the details in raw_data of sample.
This is to print the relevant fields in perf_sample__fprintf_synth()
when called from builtin-script
The sample is processed by calling perf_session__deliver_synth_event()
so that it gets included in perf report.
Sample Output:
./perf record -a -e sched:*,vpa_dtl/dtl_all/ -c 1000000000 sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.300 MB perf.data ]
./perf report
# Samples: 321 of event 'vpa-dtl'
# Event count (approx.): 321
#
# Children Self Command Shared Object Symbol
# ........ ........ ....... ................. ..............................
#
100.00% 100.00% swapper [kernel.kallsyms] [k] plpar_hcall_norets_notrace
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com>
Tested-by: Tejas Manhas <tejas05@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
Cc: Aditya Bodkhe <Aditya.Bodkhe1@ibm.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When the Dispatch Trace Log data is collected along with other events
like sched tracepoint events, it needs to be correlated and present
interleaved along with these events.
Perf events can be collected parallely across the CPUs. Hence it needs
to be ensured events/dtl entries are processed in timestamp order.
An auxtrace_queue is created for each CPU.
Data within each queue is in increasing order of timestamp. Each
auxtrace queue has a array/list of auxtrace buffers.
When processing the auxtrace buffer, the data is mmapp'ed.
All auxtrace queues is maintained in auxtrace heap.
Each queue has a queue number and a timestamp.
The queues are sorted/added to head based on the time stamp.
So always the lowest timestamp (entries to be processed first) is on top
of the heap.
The auxtrace queue needs to be allocated and heap needs to be populated
in the sorted order of timestamp.
The queue needs to be filled with data only once via
powerpc_vpadtl__update_queues() function.
powerpc_vpadtl__setup_queues() iterates through all the entries to
allocate and setup the auxtrace queue.
To add to auxtrace heap, it is required to fetch the timebase of first
entry for each of the queue.
The first entry in the queue for VPA DTL PMU has the boot timebase,
frequency details which are needed to get timestamp which is required to
correlate with other events.
The very next entry is the actual trace data that provides timestamp for
occurrence of DTL event.
Formula used to get the timestamp from dtl entry is:
((timbase from DTL entry - boot time) / frequency) * 1000000000
powerpc_vpadtl_decode() adds the boot time and frequency as part of
powerpc_vpadtl_queue structure so that it can be reused.
Each of the dtl_entry is of 48 bytes size. Sometimes it could happen
that one buffer is only partially processed (if the timestamp of
occurrence of another event is more than currently processed element in
queue, it will move on to next event).
In order to keep track of position of buffer, additional fields is added
to powerpc_vpadtl_queue structure.
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com>
Tested-by: Tejas Manhas <tejas05@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
Cc: Aditya Bodkhe <Aditya.Bodkhe1@ibm.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Dispatch Trace Log details are captured as-is in PERF_RECORD_AUXTRACE
records.
To present dtl entries as samples, create an event with name as
"vpa-dtl" and type PERF_TYPE_SYNTH.
Add perf_synth_id, "PERF_SYNTH_POWERPC_VPA_DTL" as config value for the
event.
Create a sample id to be a fixed offset from evsel id.
To present the relevant fields from the "struct dtl_entry", prepare the
entries as events of type PERF_TYPE_SYNTH.
By defining as PERF_TYPE_SYNTH type, samples can be printed as part of
perf_sample__fprintf_synth in builtin-script.c
From powerpc_vpadtl_process_auxtrace_info(), invoke
auxtrace_queues__process_index() function which will queue the auxtrace
buffers by invoke auxtrace_queues__add_event().
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com>
Tested-by: Tejas Manhas <tejas05@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
Cc: Aditya Bodkhe <Aditya.Bodkhe1@ibm.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add VPA DTL PMU auxtrace process function for "perf report -D".
The auxtrace event processing functions are defined in file
"util/powerpc-vpadtl.c".
Data structures used includes "struct powerpc_vpadtl_queue", "struct
powerpc_vpadtl" to store the auxtrace buffers in queue. Different
PERF_RECORD_XXX are generated during recording.
PERF_RECORD_AUXTRACE_INFO is processed first since it is of type
perf_user_event_type and perf session event delivers
perf_session__process_user_event() first.
Define function powerpc_vpadtl_process_auxtrace_info() to handle the
processing of PERF_RECORD_AUXTRACE_INFO records.
In this function, initialize the aux buffer queues using
auxtrace_queues__init().
Setup the required infrastructure for aux data processing.
The data is collected per CPU and auxtrace_queue is created for each
CPU.
Define powerpc_vpadtl_process_event() function to process
PERF_RECORD_AUXTRACE records.
In this, add the event to queue using auxtrace_queues__add_event() and
process the buffer in powerpc_vpadtl_dump_event().
The first entry in the buffer with timebase as zero has boot timebase
and frequency.
Remaining data is of format for "struct powerpc_vpadtl_entry".
Define the translation for dispatch_reasons and preempt_reasons, report
this when dump trace is invoked via powerpc_vpadtl_dump()
Sample output:
./perf record -a -e sched:*,vpa_dtl/dtl_all/ -c 1000000000 sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.300 MB perf.data ]
./perf report -D
0 0 0x39b10 [0x30]: PERF_RECORD_AUXTRACE size: 0x690 offset: 0 ref: 0 idx: 0 tid: -1 cpu: 0
.
. ... VPA DTL PMU data: size 1680 bytes, entries is 35
. 00000000: boot_tb: 21349649546353231, tb_freq: 512000000
. 00000030: dispatch_reason:decrementer interrupt, preempt_reason:H_CEDE, enqueue_to_dispatch_time:7064, ready_to_enqueue_time:187, waiting_to_ready_time:6611773
. 00000060: dispatch_reason:priv doorbell, preempt_reason:H_CEDE, enqueue_to_dispatch_time:146, ready_to_enqueue_time:0, waiting_to_ready_time:15359437
. 00000090: dispatch_reason:decrementer interrupt, preempt_reason:H_CEDE, enqueue_to_dispatch_time:4868, ready_to_enqueue_time:232, waiting_to_ready_time:5100709
. 000000c0: dispatch_reason:priv doorbell, preempt_reason:H_CEDE, enqueue_to_dispatch_time:179, ready_to_enqueue_time:0, waiting_to_ready_time:30714243
. 000000f0: dispatch_reason:priv doorbell, preempt_reason:H_CEDE, enqueue_to_dispatch_time:197, ready_to_enqueue_time:0, waiting_to_ready_time:15350648
. 00000120: dispatch_reason:priv doorbell, preempt_reason:H_CEDE, enqueue_to_dispatch_time:213, ready_to_enqueue_time:0, waiting_to_ready_time:15353446
. 00000150: dispatch_reason:priv doorbell, preempt_reason:H_CEDE, enqueue_to_dispatch_time:212, ready_to_enqueue_time:0, waiting_to_ready_time:15355126
. 00000180: dispatch_reason:decrementer interrupt, preempt_reason:H_CEDE, enqueue_to_dispatch_time:6368, ready_to_enqueue_time:164, waiting_to_ready_time:5104665
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com>
Tested-by: Tejas Manhas <tejas05@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
Cc: Aditya Bodkhe <Aditya.Bodkhe1@ibm.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The powerpc PMU collecting Dispatch Trace Log (DTL) entries makes use of
AUX support in perf infrastructure.
The PMU driver has the functionality to collect trace entries in the aux
buffer.
On the tools side, this data is made available as PERF_RECORD_AUXTRACE
records.
This record is generated by "perf record" command.
To enable the creation of PERF_RECORD_AUXTRACE, add functions to
initialize auxtrace records ie "auxtrace_record__init()".
Fill in fields for other callbacks like info_priv_size, info_fill, free,
recording options etc.
Define auxtrace_type as PERF_AUXTRACE_VPA_DTL. Add header file to
define vpa dtl pmu specific details.
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com>
Tested-by: Tejas Manhas <tejas05@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
Cc: Aditya Bodkhe <Aditya.Bodkhe1@ibm.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>