#!/usr/bin/stap

# usage: stap -c <cmd> scylla_row_cache_report.stp
#    or: stap -x <pid> scylla_row_cache_report.stp
#
global batch_start_time
global batch_latencies;
global partition_count;

global start_time
global latencies;


probe process.mark("row_cache_update_one_batch_start") {
    batch_start_time[tid()] = gettimeofday_ns()
}

probe process.mark("row_cache_update_one_batch_end") {
    if (batch_start_time[tid()]) {
        lat = (gettimeofday_ns() - batch_start_time[tid()]);
        batch_latencies <<< lat;
        partition_count <<< $arg1;
        delete batch_start_time[tid()]
    }
}

probe process.mark("row_cache_update_start") {
    start_time[tid()] = gettimeofday_us()
}

probe process.mark("row_cache_update_end") {
    if (start_time[tid()]) {
        lat = (gettimeofday_us() - start_time[tid()]);
        latencies <<< lat;
        delete start_time[tid()]
    }
}

probe begin {
    printf("Measuring Scylla row cache update times ");
}

probe end {
    println();
    println("Total update time, (usec)");
    println(@hist_log(latencies));
    println("Time spent per partition batch (nsec)");
    print(@hist_log(batch_latencies));
    println("Partitions updated per batch:");
    println(@hist_log(partition_count));

    println("Total partitions updated:");
    println(@sum(partition_count));
    println("Average time spent per partition batch (nsec)");
    println(@avg(batch_latencies));
    println("Average time per partition (nsec)");
    println(@sum(batch_latencies) / @sum(partition_count));
}