If the input perf.data has a kcore_dir, copy it into the output, since
at least the kallsyms in the kcore_dir will be useful to the output.
Example:
Before:
$ ls -lR perf.data-from-desktop
perf.data-from-desktop:
total 916
-rw------- 1 user user 931756 May 19 09:55 data
drwx------ 2 user user 4096 May 19 09:55 kcore_dir
perf.data-from-desktop/kcore_dir:
total 42952
-r-------- 1 user user 7582467 May 19 09:55 kallsyms
-r-------- 1 user user 36388864 May 19 09:55 kcore
-r-------- 1 user user 4828 May 19 09:55 modules
$ perf inject -i perf.data-from-desktop -o injected-perf.data
$ ls -lR injected-perf.data
-rw------- 1 user user 931320 May 20 15:08 injected-perf.data
After:
$ perf inject -i perf.data-from-desktop -o injected-perf.data
$ ls -lR injected-perf.data
injected-perf.data:
total 916
-rw------- 1 user user 931320 May 20 15:21 data
drwx------ 2 user user 4096 May 20 15:21 kcore_dir
injected-perf.data/kcore_dir:
total 42952
-r-------- 1 user user 7582467 May 20 15:21 kallsyms
-r-------- 1 user user 36388864 May 20 15:21 kcore
-r-------- 1 user user 4828 May 20 15:21 modules
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220520132404.25853-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently it discards a lock_stat for a lock instance when there's a
broken lock_seq_stat in a single task for the lock. But it also means
that the existing (and later) valid lock stat info for that lock will
be discarded as well.
This is not ideal since we can lose many valuable info because of a
single failure. Actually those failures are indepent to the existing
stat. So we can only discard the broken lock_seq_stat but keep the
valid lock_stat.
The discarded lock_seq_stat will be reallocated in a subsequent event
with SEQ_STATE_UNINITIALIZED which will be ignored until it see the
start of the next sequence. So it should be ok just free it.
Before:
$ perf lock report -F acquired,contended,avg_wait
Warning:
Processed 1401603 events and lost 18 chunks!
Check IO/CPU overload!
Name acquired contended avg wait (ns)
rcu_read_lock 251225 0 0
&(ei->i_block_re... 8731 0 0
&sb->s_type->i_l... 8731 0 0
hrtimer_bases.lock 5261 0 0
hrtimer_bases.lock 2626 0 0
hrtimer_bases.lock 1953 0 0
hrtimer_bases.lock 1382 0 0
cpu_hotplug_lock 1350 0 0
hrtimer_bases.lock 1273 0 0
hrtimer_bases.lock 1269 0 0
hrtimer_bases.lock 1198 0 0
...
New:
Name acquired contended avg wait (ns)
rcu_read_lock 251225 0 0
tk_core.seq.seqc... 54074 0 0
&xa->xa_lock 17470 0 0
&ei->i_es_lock 17464 0 0
&ei->i_raw_lock 9391 0 0
&mapping->privat... 8734 0 0
&ei->i_data_sem 8731 0 0
&(ei->i_block_re... 8731 0 0
&sb->s_type->i_l... 8731 0 0
jiffies_seq.seqc... 6953 0 0
&mm->mmap_lock 6889 0 0
balancing 5768 0 0
hrtimer_bases.lock 5261 0 0
...
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220521010811.932703-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Perf BPF filter test fails in environment where "clang" is not
installed.
Test failure logs:
<<>>
42: BPF filter :
42.1: Basic BPF filtering : Skip
42.2: BPF pinning : FAILED!
42.3: BPF prologue generation : FAILED!
<<>>
Enabling verbose option provided debug logs which says clang/llvm needs
to be installed. Snippet of verbose logs:
<<>>
42.2: BPF pinning :
--- start ---
test child forked, pid 61423
ERROR: unable to find clang.
Hint: Try to install latest clang/llvm to support BPF.
Check your $PATH
<<logs_here>>
Failed to compile test case: 'Basic BPF llvm compile'
Unable to get BPF object, fix kbuild first
test child finished with -1
---- end ----
BPF filter subtest 2: FAILED!
<<>>
Here subtests, "BPF pinning" and "BPF prologue generation" failed and
logs shows clang/llvm is needed. After installing clang, testcase
passes.
Reason on why subtest failure happens though logs has proper debug
information:
Main function __test__bpf calls test_llvm__fetch_bpf_obj by
passing 4th argument as true ( 4th arguments maps to parameter
"force" in test_llvm__fetch_bpf_obj ). But this will cause
test_llvm__fetch_bpf_obj to skip the check for clang/llvm.
Snippet of code part which checks for clang based on
parameter "force" in test_llvm__fetch_bpf_obj:
<<>>
if (!force && (!llvm_param.user_set_param &&
<<>>
Since force is set to "false", test won't get skipped and fails to
compile test case. The BPF code compilation needs clang, So pass the
fourth argument as "false" and also skip the test if reason for return
is "TEST_SKIP"
After the patch:
<<>>
42: BPF filter :
42.1: Basic BPF filtering : Skip
42.2: BPF pinning : Skip
42.3: BPF prologue generation : Skip
<<>>
Fixes: ba1fae431e ("perf test: Add 'perf test BPF'")
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lore.kernel.org/r/20220511115438.84032-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The session topology test fails in powerpc pSeries platform.
Test logs:
<<>>
Session topology : FAILED!
<<>>
This testcases tests cpu topology by checking the core_id and socket_id
stored in perf_env from perf session. The data from perf session is
compared with the cpu topology information from
"/sys/devices/system/cpu/cpuX/topology" like core_id,
physical_package_id.
In case of virtual environment, detail like physical_package_id is
restricted to be exposed. Hence physical_package_id is set to -1. The
testcase fails on such platforms since socket_id can't be fetched from
topology info.
Skip the testcase in powerpc if physical_package_id returns -1.
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>---
Tested-by: Disha Goel <disgoel@linux.vnet.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20220511114959.84002-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The compilation on s390 results in this error:
# make DEBUG=y bench/numa.o
...
bench/numa.c: In function ‘__bench_numa’:
bench/numa.c:1749:81: error: ‘%d’ directive output may be truncated
writing between 1 and 11 bytes into a region of size between
10 and 20 [-Werror=format-truncation=]
1749 | snprintf(tname, sizeof(tname), "process%d:thread%d", p, t);
^~
...
bench/numa.c:1749:64: note: directive argument in the range
[-2147483647, 2147483646]
...
#
The maximum length of the %d replacement is 11 characters because of the
negative sign. Therefore extend the array by two more characters.
Output after:
# make DEBUG=y bench/numa.o > /dev/null 2>&1; ll bench/numa.o
-rw-r--r-- 1 root root 418320 May 19 09:11 bench/numa.o
#
Fixes: 3aff8ba0a4 ("perf bench numa: Avoid possible truncation when using snprintf()")
Suggested-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20220520081158.2990006-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The X86 specific arch__intr_reg_mask() is to check whether the kernel
and hardware can collect XMM registers. But it doesn't work on some
hybrid platform.
Without the patch on ADL-N:
$ perf record -I?
available registers: AX BX CX DX SI DI BP SP IP FLAGS CS SS R8 R9 R10
R11 R12 R13 R14 R15
The config of the test event doesn't contain the PMU information. The
kernel may fail to initialize it on the correct hybrid PMU and return
the wrong non-supported information.
Add the PMU information into the config for the hybrid platform. The
same register set is supported among different hybrid PMUs. Checking
the first available one is good enough.
With the patch on ADL-N:
$ perf record -I?
available registers: AX BX CX DX SI DI BP SP IP FLAGS CS SS R8 R9 R10
R11 R12 R13 R14 R15 XMM0 XMM1 XMM2 XMM3 XMM4 XMM5 XMM6 XMM7 XMM8 XMM9
XMM10 XMM11 XMM12 XMM13 XMM14 XMM15
Fixes: 6466ec14aa ("perf regs x86: Add X86 specific arch__intr_reg_mask()")
Reported-by: Ammy Yi <ammy.yi@intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: 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: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220518145125.1494156-1-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
"perf all PMU test" picks the input events from "perf list --raw-dump
pmu" list and runs "perf stat -e" for each of the event in the list. In
case of powerpc, the PowerVM environment supports events from hv_24x7
and hv_gpci PMU which is of example format like below:
- hv_24x7/CPM_ADJUNCT_INST,domain=?,core=?/
- hv_gpci/event,partition_id=?/
The value for "?" needs to be filled in depending on system and
respective event. CPM_ADJUNCT_INST needs have core value and domain
value. hv_gpci event needs partition_id. Similarly, there are other
events for hv_24x7 and hv_gpci having "?" in event format. Hence skip
these events on powerpc platform since values like partition_id, domain
is specific to system and event.
Fixes: 3d5ac9effc ("perf test: Workload test of all PMUs")
Signed-off-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Link: https://lore.kernel.org/r/20220520101236.17249-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The commit 94dbfd6781 ("perf parse-events: Architecture specific
leader override") introduced a feature to reorder the slots event to
fulfill the restriction of the perf metrics topdown group. But the
feature doesn't work on the hybrid machine.
$ perf stat -e "{cpu_core/instructions/,cpu_core/slots/,cpu_core/topdown-retiring/}" -a sleep 1
Performance counter stats for 'system wide':
<not counted> cpu_core/instructions/
<not counted> cpu_core/slots/
<not supported> cpu_core/topdown-retiring/
1.002871801 seconds time elapsed
A hybrid platform has a different PMU name for the core PMUs, while
current perf hard code the PMU name "cpu".
Introduce a new function to check whether the system supports the perf
metrics feature. The result is cached for the future usage.
For X86, the core PMU name always has "cpu" prefix.
With the patch:
$ perf stat -e "{cpu_core/instructions/,cpu_core/slots/,cpu_core/topdown-retiring/}" -a sleep 1
Performance counter stats for 'system wide':
76,337,010 cpu_core/slots/
10,416,809 cpu_core/instructions/
11,692,372 cpu_core/topdown-retiring/
1.002805453 seconds time elapsed
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220518143900.1493980-5-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The evsel->name may have a different format for a topdown event, a pure
topdown name (e.g., topdown-fe-bound), or a PMU name + a topdown name
(e.g., cpu/topdown-fe-bound/). The cpu/topdown-fe-bound/ kind format
isn't supported by the arch_evlist__leader(). This format is a very
common format for a hybrid platform, which requires specifying the PMU
name for each event.
Without the patch,
$ perf stat -e '{instructions,slots,cpu/topdown-fe-bound/}' -a sleep 1
Performance counter stats for 'system wide':
<not counted> instructions
<not counted> slots
<not supported> cpu/topdown-fe-bound/
1.003482041 seconds time elapsed
Some events weren't counted. Try disabling the NMI watchdog:
echo 0 > /proc/sys/kernel/nmi_watchdog
perf stat ...
echo 1 > /proc/sys/kernel/nmi_watchdog
The events in group usually have to be from the same PMU. Try reorganizing the group.
With the patch,
$ perf stat -e '{instructions,slots,cpu/topdown-fe-bound/}' -a sleep 1
Performance counter stats for 'system wide':
157,383,996 slots
25,011,711 instructions
27,441,686 cpu/topdown-fe-bound/
1.003530890 seconds time elapsed
Fixes: bc355822f0 ("perf parse-events: Move slots only with topdown")
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220518143900.1493980-4-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If any member in a group has a different cpu mask than the other
members, the current perf stat disables group. when the perf metrics
topdown events are part of the group, the below <not supported> error
will be triggered.
$ perf stat -e "{slots,topdown-retiring,uncore_imc_free_running_0/dclk/}" -a sleep 1
WARNING: grouped events cpus do not match, disabling group:
anon group { slots, topdown-retiring, uncore_imc_free_running_0/dclk/ }
Performance counter stats for 'system wide':
141,465,174 slots
<not supported> topdown-retiring
1,605,330,334 uncore_imc_free_running_0/dclk/
The perf metrics topdown events must always be grouped with a slots
event as leader.
Factor out evsel__remove_from_group() to only remove the regular events
from the group.
Remove evsel__must_be_in_group(), since no one use it anymore.
With the patch, the topdown events aren't broken from the group for the
splitting.
$ perf stat -e "{slots,topdown-retiring,uncore_imc_free_running_0/dclk/}" -a sleep 1
WARNING: grouped events cpus do not match, disabling group:
anon group { slots, topdown-retiring, uncore_imc_free_running_0/dclk/ }
Performance counter stats for 'system wide':
346,110,588 slots
124,608,256 topdown-retiring
1,606,869,976 uncore_imc_free_running_0/dclk/
1.003877592 seconds time elapsed
Fixes: a9a1790247 ("perf stat: Ensure group is defined on top of the same cpu mask")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220518143900.1493980-3-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The patch ("perf evlist: Keep topdown counters in weak group") fixes the
perf metrics topdown event issue when the topdown events are in a weak
group on a non-hybrid platform. However, it doesn't work for the hybrid
platform.
$./perf stat -e '{cpu_core/slots/,cpu_core/topdown-bad-spec/,
cpu_core/topdown-be-bound/,cpu_core/topdown-fe-bound/,
cpu_core/topdown-retiring/,cpu_core/branch-instructions/,
cpu_core/branch-misses/,cpu_core/bus-cycles/,cpu_core/cache-misses/,
cpu_core/cache-references/,cpu_core/cpu-cycles/,cpu_core/instructions/,
cpu_core/mem-loads/,cpu_core/mem-stores/,cpu_core/ref-cycles/,
cpu_core/cache-misses/,cpu_core/cache-references/}:W' -a sleep 1
Performance counter stats for 'system wide':
751,765,068 cpu_core/slots/ (84.07%)
<not supported> cpu_core/topdown-bad-spec/
<not supported> cpu_core/topdown-be-bound/
<not supported> cpu_core/topdown-fe-bound/
<not supported> cpu_core/topdown-retiring/
12,398,197 cpu_core/branch-instructions/ (84.07%)
1,054,218 cpu_core/branch-misses/ (84.24%)
539,764,637 cpu_core/bus-cycles/ (84.64%)
14,683 cpu_core/cache-misses/ (84.87%)
7,277,809 cpu_core/cache-references/ (77.30%)
222,299,439 cpu_core/cpu-cycles/ (77.28%)
63,661,714 cpu_core/instructions/ (84.85%)
0 cpu_core/mem-loads/ (77.29%)
12,271,725 cpu_core/mem-stores/ (77.30%)
542,241,102 cpu_core/ref-cycles/ (84.85%)
8,854 cpu_core/cache-misses/ (76.71%)
7,179,013 cpu_core/cache-references/ (76.31%)
1.003245250 seconds time elapsed
A hybrid platform has a different PMU name for the core PMUs, while
the current perf hard code the PMU name "cpu".
The evsel->pmu_name can be used to replace the "cpu" to fix the issue.
For a hybrid platform, the pmu_name must be non-NULL. Because there are
at least two core PMUs. The PMU has to be specified.
For a non-hybrid platform, the pmu_name may be NULL. Because there is
only one core PMU, "cpu". For a NULL pmu_name, we can safely assume that
it is a "cpu" PMU.
In case other PMUs also define the "slots" event, checking the PMU type
as well.
With the patch,
$ perf stat -e '{cpu_core/slots/,cpu_core/topdown-bad-spec/,
cpu_core/topdown-be-bound/,cpu_core/topdown-fe-bound/,
cpu_core/topdown-retiring/,cpu_core/branch-instructions/,
cpu_core/branch-misses/,cpu_core/bus-cycles/,cpu_core/cache-misses/,
cpu_core/cache-references/,cpu_core/cpu-cycles/,cpu_core/instructions/,
cpu_core/mem-loads/,cpu_core/mem-stores/,cpu_core/ref-cycles/,
cpu_core/cache-misses/,cpu_core/cache-references/}:W' -a sleep 1
Performance counter stats for 'system wide':
766,620,266 cpu_core/slots/ (84.06%)
73,172,129 cpu_core/topdown-bad-spec/ # 9.5% bad speculation (84.06%)
193,443,341 cpu_core/topdown-be-bound/ # 25.0% backend bound (84.06%)
403,940,929 cpu_core/topdown-fe-bound/ # 52.3% frontend bound (84.06%)
102,070,237 cpu_core/topdown-retiring/ # 13.2% retiring (84.06%)
12,364,429 cpu_core/branch-instructions/ (84.03%)
1,080,124 cpu_core/branch-misses/ (84.24%)
564,120,383 cpu_core/bus-cycles/ (84.65%)
36,979 cpu_core/cache-misses/ (84.86%)
7,298,094 cpu_core/cache-references/ (77.30%)
227,174,372 cpu_core/cpu-cycles/ (77.31%)
63,886,523 cpu_core/instructions/ (84.87%)
0 cpu_core/mem-loads/ (77.31%)
12,208,782 cpu_core/mem-stores/ (77.31%)
566,409,738 cpu_core/ref-cycles/ (84.87%)
23,118 cpu_core/cache-misses/ (76.71%)
7,212,602 cpu_core/cache-references/ (76.29%)
1.003228667 seconds time elapsed
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220518143900.1493980-2-kan.liang@linux.intel.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>
It can be convenient to put a string value into a ptwrite payload as
a quick and easy way to identify what is being printed.
To make that useful, if the Intel ptwrite payload value contains only
printable ASCII characters padded with NULLs, then print it also as a
string.
Using the example program from the "Emulated PTWRITE" section of
tools/perf/Documentation/perf-intel-pt.txt:
$ echo -n "Hello" | od -t x8
0000000 0000006f6c6c6548
0000005
$ perf record -e intel_pt//u ./eg_ptw 0x0000006f6c6c6548
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.016 MB perf.data ]
$ perf script --itrace=ew intel-pt-events.py
Intel PT Branch Trace, Power Events, Event Trace and PTWRITE
Switch In 38524/38524 [001] 24166.044995916 0/0
eg_ptw 38524/38524 [001] 24166.045380004 ptwrite jmp IP: 0 payload: 0x6f6c6c6548 Hello 56532c7ce196 perf_emulate_ptwrite+0x16 (/home/ahunter/git/work/eg_ptw)
End
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220509152400.376613-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It can be convenient to put a string value into a ptwrite payload as
a quick and easy way to identify what is being printed.
To make that useful, if the Intel ptwrite payload value contains only
printable ASCII characters padded with NULLs, then print it also as a
string.
Using the example program from the "Emulated PTWRITE" section of
tools/perf/Documentation/perf-intel-pt.txt:
$ echo -n "Hello" | od -t x8
0000000 0000006f6c6c6548
0000005
$ perf record -e intel_pt//u ./eg_ptw 0x0000006f6c6c6548
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.016 MB perf.data ]
$ perf script --itrace=ew
eg_ptw 35563 [005] 18256.087338: ptwrite: IP: 0 payload: 0x6f6c6c6548 Hello 55e764db5196 perf_emulate_ptwrite+0x16 (/home/user/eg_ptw)
$
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220509152400.376613-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
ptwrite is an Intel x86 instruction that writes arbitrary values into an
Intel PT trace. It is not supported on all hardware, so provide an
alternative that makes use of TNT packets to convey the payload data.
TNT packets encode Taken/Not-taken conditional branch information, so
taking branches based on the payload value will encode the value into
the TNT packet. Refer to the changes to the documentation file
perf-intel-pt.txt in this patch for an example.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220509152400.376613-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
