dumpsync
dumpsync.iowait += iotime - dumpsync.iowaitts;
dumpsync.iowaitts = gethrtime();
dumpsync.iotime += dumpsync.iowaitts - iotime;
dumpsync.nwrite += size;
dumpsync_t *ds = &dumpsync;
static dumpsync_t dumpsync; /* synchronization vars */