DTrace script to collect statistics about arc misses

arc_miss.d

#!/usr/sbin/dtrace -s

#pragma D option quiet
#pragma D option dynvarsize=16m

BEGIN
{
    printf("tracing...\n");
}

fbt::fop_*:entry
{
    self->func = probefunc;
}

fbt::fop_*:return
{
    self->func = 0;
}

sdt:zfs::arc-miss
/self->func != 0/
{
    @miss[execname, self->func] = count();
}

sdt:zfs::arc-miss
/self->func == 0/
{
    @miss[execname, "others"] = count();
}

sdt:zfs::arc-miss
{
    /* Use the aggregation instead of using a global variable
       to count the total of misses correctly. */  
    @miss["misses", ""] = count();
}

sdt:zfs::l2arc-miss
/self->func != 0/
{
    @l2miss[execname, self->func] = count();
}

sdt:zfs::l2arc-miss
/self->func == 0/
{
    @l2miss[execname, "others"] = count();
}

sdt:zfs::l2arc-miss
{
    /* Use the aggregation instead of using a global variable
       to count the total of misses correctly. */  
    @l2miss["misses", ""] = count();
}

profile:::tick-10s
{
    tick++;
}

profile:::tick-10s
/tick == 10/
{
    printf("arc\n");
    printa("%s, %s, %@d\n", @miss);
    printf("l2arc\n");
    printa("%s, %s, %@d\n", @l2miss);
    exit(0);
}