Re: [PATCH] perf data: export to JSON

From: Nicholas Fraser
Date: Wed Mar 31 2021 - 06:33:24 EST


Hi Arnaldo,

Thanks for the review. I'll send a replacement patch with your suggestions.

On 2021-03-24 9:30 a.m., Arnaldo Carvalho de Melo wrote:
> Do you plan to output the headers too? I think we should, for
> completeness.

I've added the headers, at least the ones that seemed important or easy to
output. The result looks like this:

"headers": {
"header-version": 1,
"captured-on": "2021-03-30T19:24:22Z",
"data-offset": 304,
"data-size": 35000,
"feat-offset": 35304,
"hostname": "foundry",
"os-release": "5.11.8-arch1-1",
"arch": "x86_64",
"cpu-desc": "Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz",
"cpuid": "GenuineIntel,6,142,10",
"nrcpus-online": 8,
"nrcpus-avail": 8,
"perf-version": "5.11.gf40ddce88593",
"cmdline": [
"/usr/bin/perf",
"record",
"vkcube"
]
},

(I've thus far avoided outputting anything we don't use; I'm unlikely to design
a useful format for data if I don't have a real use case for it. We will
probably make use of some of the headers though so it's worth doing now.)

Nick