sd-max-xfer-size.d

#!/usr/sbin/dtrace -Cs
#pragma D option quiet

#define SD_TO_DEVINFO(un)	((struct dev_info *)((un)->un_sd->sd_dev))
#define DEV_NAME(un) \
      stringof(`devnamesp[SD_TO_DEVINFO(un)->devi_major].dn_name) /* ` */
#define DEV_INST(un)		(SD_TO_DEVINFO(un)->devi_instance)
#define	SD_GET_XBUF(bp)		((struct sd_xbuf *)((bp)->b_private))
#define	SD_GET_UN(bp)		((SD_GET_XBUF(bp))->xb_un)

:sd:sdintr:entry {
    this->bp                = (struct buf *)args[0]->pkt_private;
    this->un                = SD_GET_UN(this->bp);
    this->un_max_xfer_size  = this->un->un_max_xfer_size;
    this->devname           = DEV_NAME(this->un);
    this->inst              = DEV_INST(this->un);
    @[this->devname, this->inst, this->un_max_xfer_size] \
                            = count();
}
END {
    printf("instance\txfer sz \tcount\n");
    printa("%s%-8d\t%-8d\t%-8@d\n", @);
}