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d0713d4ca3
This adds a feature to export perf data to JSON.
The resolved symbols are exported into the JSON so that external tools
don't need to load the dsos themselves (or even have access to them at
all.) This makes it easy to load and analyze perf data with standalone
tools where direct perf or libbabeltrace integration is impractical.
The exporter uses a minimal inline JSON encoding without any external
dependencies. Currently it only outputs some headers and sample metadata
but it's easily extensible.
Use it like this:
$ perf data convert --to-json out.json
Committer notes:
Fixup a __printf() bug that broke the build:
util/data-convert-json.c:103:11: error: expected ‘)’ before numeric constant
103 | __(printf, 5, 6)
| ^~
| )
util/data-convert-json.c: In function ‘output_sample_callchain_entry’:
util/data-convert-json.c:124:2: error: implicit declaration of function ‘output_json_key_format’; did you mean ‘output_json_format’? [-Werror=implicit-function-declaration]
124 | output_json_key_format(out, false, 5, "ip", "\"0x%" PRIx64 "\"", ip);
| ^~~~~~~~~~~~~~~~~~~~~~
| output_json_format
Also had to add this patch to fix errors reported by various versions of
clang:
- if (al && al->sym && al->sym->name && strlen(al->sym->name) > 0) {
+ if (al && al->sym && al->sym->namelen) {
al->sym->name is a zero sized array, to avoid one extra alloc in the
symbol__new() constructor, sym->namelen carries its strlen.
Committer testing:
$ ls -la out.json
ls: cannot access 'out.json': No such file or directory
$ perf record sleep 0.1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.001 MB perf.data (8 samples) ]
$ perf report --stats | grep -w SAMPLE
SAMPLE events: 8
$ perf data convert --to-json out.json
[ perf data convert: Converted 'perf.data' into JSON data 'out.json' ]
[ perf data convert: Converted and wrote 0.002 MB (8 samples) ]
$ ls -la out.json
-rw-rw-r--. 1 acme acme 2017 Apr 26 17:29 out.json
$ cat out.json
{
"linux-perf-json-version": 1,
"headers": {
"header-version": 1,
"captured-on": "2021-04-26T20:28:57Z",
"data-offset": 432,
"data-size": 1016,
"feat-offset": 1448,
"hostname": "five",
"os-release": "5.11.14-200.fc33.x86_64",
"arch": "x86_64",
"cpu-desc": "AMD Ryzen 9 3900X 12-Core Processor",
"cpuid": "AuthenticAMD,23,113,0",
"nrcpus-online": 24,
"nrcpus-avail": 24,
"perf-version": "5.12.gee134f3189bd",
"cmdline": [
"/home/acme/bin/perf",
"record",
"sleep",
"0.1"
]
},
"samples": [
{
"timestamp": 170517539043684,
"pid": 375844,
"tid": 375844,
"comm": "sleep",
"callchain": [
{
"ip": "0xffffffffa6268827"
}
]
},
{
"timestamp": 170517539048443,
"pid": 375844,
"tid": 375844,
"comm": "sleep",
"callchain": [
{
"ip": "0xffffffffa661359d"
}
]
},
{
"timestamp": 170517539051018,
"pid": 375844,
"tid": 375844,
"comm": "sleep",
"callchain": [
{
"ip": "0xffffffffa6311e18"
}
]
},
{
"timestamp": 170517539053652,
"pid": 375844,
"tid": 375844,
"comm": "sleep",
"callchain": [
{
"ip": "0x7fdb77b4812b",
"symbol": "_dl_start",
"dso": "ld-2.32.so"
}
]
},
{
"timestamp": 170517539055306,
"pid": 375844,
"tid": 375844,
"comm": "sleep",
"callchain": [
{
"ip": "0xffffffffa6269286"
}
]
},
{
"timestamp": 170517539057590,
"pid": 375844,
"tid": 375844,
"comm": "sleep",
"callchain": [
{
"ip": "0xffffffffa62abd8b"
}
]
},
{
"timestamp": 170517539067559,
"pid": 375844,
"tid": 375844,
"comm": "sleep",
"callchain": [
{
"ip": "0x7fdb77b5e9e9",
"symbol": "__GI___tunables_init",
"dso": "ld-2.32.so"
}
]
},
{
"timestamp": 170517539282452,
"pid": 375844,
"tid": 375844,
"comm": "sleep",
"callchain": [
{
"ip": "0x7fdb779978d2",
"symbol": "getenv",
"dso": "libc-2.32.so"
}
]
}
]
}
$
Signed-off-by: Nicholas Fraser <nfraser@codeweavers.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
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>
Cc: Tan Xiaojun <tanxiaojun@huawei.com>
Cc: Ulrich Czekalla <uczekalla@codeweavers.com>
Link: http://lore.kernel.org/lkml/3884969f-804d-2f53-c648-e2b0bd85edff@codeweavers.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
55 lines
1.0 KiB
Plaintext
55 lines
1.0 KiB
Plaintext
perf-data(1)
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============
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NAME
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----
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perf-data - Data file related processing
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SYNOPSIS
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--------
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[verse]
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'perf data' [<common options>] <command> [<options>]",
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DESCRIPTION
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-----------
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Data file related processing.
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COMMANDS
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--------
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convert::
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Converts perf data file into another format.
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It's possible to set data-convert debug variable to get debug messages from conversion,
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like:
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perf --debug data-convert data convert ...
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OPTIONS for 'convert'
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---------------------
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--to-ctf::
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Triggers the CTF conversion, specify the path of CTF data directory.
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--to-json::
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Triggers JSON conversion. Specify the JSON filename to output.
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--tod::
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Convert time to wall clock time.
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-i::
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Specify input perf data file path.
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-f::
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--force::
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Don't complain, do it.
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-v::
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--verbose::
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Be more verbose (show counter open errors, etc).
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--all::
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Convert all events, including non-sample events (comm, fork, ...), to output.
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Default is off, only convert samples.
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SEE ALSO
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--------
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linkperf:perf[1]
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[1] Common Trace Format - http://www.efficios.com/ctf
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