Off-CPU data model for UI consumption

offcpu_data.json

//Frame dictionary
{"FrameId1": "java.lang.blah.blah:80", "...": "..."}

//Syscall dictionary
{"SycallId1": "open()", "...": "..."}

//Data model for a unique backtrace in off-cpu stack sample tree
{
    backtrace_id: 35,
    ctx_switches : {
        voluntary: {
            count: 95,
            latency_usec: {
                "max" : 3500,
                "q999": 3450,
                "q99" : 3100,
                "q98" : 2800,
                "q95" : 1900,
                "q90" : 1800,
                "q75" : 1600,
                "median" : 1300,
                "mean": 1500,
                "sd" : 700 },
            sched_delay_usec: {
                "max" : 200,
                "q999": 150,
                "q99" : 120,
                "q98" : 100,
                "q95" : 95,
                "q90" : 80,
                "q75" : 40,
                "median" : 25,
                "mean": 35,
                "sd" : 14 },
            migration_count: 15 },
        involuntary: {
            count: 22,
            latency_usec: {
                "max" : 350,
                "q999": 345,
                "q99" : 310,
                "q98" : 280,
                "q95" : 190,
                "q90" : 180,
                "q75" : 160,
                "median" : 130,
                "mean": 150,
                "sd" : 70 },
            migration_count: 3 },
        syscalls: {
            distinguished: [// "all entries with total time = mean * count >= q20(total-time distribution)"
                {
                    id: 10,
                    count: 103,
                    latency_us: {
                        "max" : 100,
                        "q999": 50,
                        "q99" : 20,
                        "q98" : 10,
                        "q95" : 7,
                        "q90" : 6,
                        "q75" : 5,
                        "median" : 4,
                        "mean": 10,
                        "sd" : 8 }},
                {
                    id: 15,
                    count: 56,
                    latency_us: {
                        "max" : 100,
                        "q999": 50,
                        "q99" : 20,
                        "q98" : 10,
                        "q95" : 7,
                        "q90" : 6,
                        "q75" : 5,
                        "median" : 4,
                        "mean": 10,
                        "sd" : 8 }}
            ],
            others: {
                ids: [19, 54, 12, 7],
                count: 95,
                latency_us: {
                    "max" : 100,
                    "q999": 50,
                    "q99" : 20,
                    "q98" : 10,
                    "q95" : 7,
                    "q90" : 6,
                    "q75" : 5,
                    "median" : 4,
                    "mean": 10,
                    "sd" : 8 }}}}}