fsync_count_by_fd.d

tracepoint:syscalls:sys_exit_fsync,tracepoint:syscalls:sys_exit_fdatasync
/comm == str($1)/
{
        @bytes = lhist((nsecs - @start[tid]) / 1000, 0, 1500, 100);
        delete(@start[tid]);
}

tracepoint:syscalls:sys_enter_fsync,tracepoint:syscalls:sys_enter_fdatasync
/comm == str($1)/
{
        @start[tid] = nsecs;
        @fsyncs[args->fd] = count();
        if (@fd_to_filename[args->fd]) {
        } else {
                @fd_to_filename[args->fd] = 1;
                system("echo -n 'fd %d -> ' &1>&2 | readlink /proc/%d/fd/%d", args->fd, pid, args->fd);
        }
}

END {
        clear(@fd_to_filename);
}

mysql.bash

$ RUSTFLAGS='-C target-cpu=native' cargo run --release -- -e mysql
# 32 threads, 1000 records per thread
Executing mysql_write..
Elapsed: 3813ms
Records: 32000
Insertions/second: 10666

# In another terminal..

personal@napkin:~$ sudo bpftrace --unsafe fsync_count_by_fd.d mysqld
Attaching 5 probes...
fd 5 -> /var/lib/mysql/ib_logfile0
fd 99 -> /var/lib/mysql/binlog.000019
fd 34 -> /var/lib/mysql/napkin/products.ibd
fd 11 -> /var/lib/mysql/#ib_16384_0.dblwr
fd 27 -> /var/lib/mysql/mysql.ibd
fd 15 -> /var/lib/mysql/undo_002
fd 13 -> /var/lib/mysql/undo_001
fd 9 -> /var/lib/mysql/ibdata1
fd 12 -> /var/lib/mysql/#ib_16384_1.dblwr
^C

@bytes:
[0, 100)             386 |@@@@@@@@@@                                          |
[100, 200)            11 |                                                    |
[200, 300)           739 |@@@@@@@@@@@@@@@@@@@                                 |
[300, 400)          1953 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
[400, 500)           418 |@@@@@@@@@@@                                         |
[500, 600)           400 |@@@@@@@@@@                                          |
[600, 700)           264 |@@@@@@@                                             |
[700, 800)           224 |@@@@@                                               |
[800, 900)           855 |@@@@@@@@@@@@@@@@@@@@@@                              |
[900, 1000)         1346 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@                 |
[1000, 1100)         590 |@@@@@@@@@@@@@@@                                     |
[1100, 1200)         215 |@@@@@                                               |
[1200, 1300)         165 |@@@@                                                |
[1300, 1400)         118 |@@@                                                 |
[1400, 1500)         111 |@@                                                  |
[1500, ...)          399 |@@@@@@@@@@                                          |


@fsyncs[9]: 2
@fsyncs[12]: 2
@fsyncs[27]: 12
@fsyncs[34]: 47
@fsyncs[13]: 86
@fsyncs[15]: 93
@fsyncs[11]: 103
@fsyncs[99]: 2962
@fsyncs[5]: 4887

napkin.bash

$ target/release/base-rates -e disk_write_sequential_fsync

Executing disk_write_sequential_fsync..

[Sequential Disk Write, Fsync <8 KiB>] Iterations in 5007 miliseconds, no overhead: 5,559
[Sequential Disk Write, Fsync <8 KiB>] Iterations / second: 1,110
[Sequential Disk Write, Fsync <8 KiB>] Bytes handled per iteration: 8192 bytes
[Sequential Disk Write, Fsync <8 KiB>] Total bytes processed: 43.430 MiB
[Sequential Disk Write, Fsync <8 KiB>] Throughput: 8.674 MiB/s
[Sequential Disk Write, Fsync <8 KiB>] Avg single iteration: 900 μs
[Sequential Disk Write, Fsync <8 KiB>] Avg single iteration cycles: 2792570.90
[Sequential Disk Write, Fsync <8 KiB>] Time to process 1 MiB: 115 ms
[Sequential Disk Write, Fsync <8 KiB>] Time to process 1 GiB: 118.07 s
[Sequential Disk Write, Fsync <8 KiB>] Time to process 1 TiB: 33.59 hours

# in other terminal

personal@napkin:~$ sudo bpftrace --unsafe fsync_count_by_fd.d base-rates
Attaching 5 probes...
fd 3 -> /tmp/napkin.txt
fd 4 -> /tmp/napkin.txt
^C

@bytes:
[700, 800)           153 |@@                                                  |
[800, 900)          3385 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
[900, 1000)         2004 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@                      |
[1000, 1100)          71 |@                                                   |
[1100, 1200)          17 |                                                    |
[1200, 1300)          17 |                                                    |
[1300, 1400)           7 |                                                    |
[1400, 1500)           3 |                                                    |
[1500, ...)           11 |                                                    |


@fsyncs[3]: 109
@fsyncs[4]: 5559