static void lat_target_success(struct thread_data *td)
{
const unsigned int qd = td->latency_qd;
td->latency_qd_low = td->latency_qd;
/*
* If we haven't failed yet, we double up to a failing value instead
* of bisecting from highest possible queue depth. If we have set
* a limit other than td->o.iodepth, bisect between that.
*/
if (td->latency_qd_high != td->o.iodepth)
td->latency_qd = (td->latency_qd + td->latency_qd_high) / 2;
else
td->latency_qd *= 2;
if (td->latency_qd > td->o.iodepth)
td->latency_qd = td->o.iodepth;
dprint(FD_RATE, "Ramped up: %d %d %d\n", td->latency_qd_low, td->latency_qd, td->latency_qd_high);
/*
* Same as last one, we are done
*/
if (td->latency_qd == qd)
td->done = 1;
lat_new_cycle(td);
}
/*
* We had an IO outside the latency target. Reduce the queue depth. If we
* are at QD=1, then it's time to give up.
*/
static int __lat_target_failed(struct thread_data *td)
{
if (td->latency_qd == 1)
return 1;
td->latency_qd_high = td->latency_qd;
td->latency_qd = (td->latency_qd + td->latency_qd_low) / 2;
dprint(FD_RATE, "Ramped down: %d %d %d\n", td->latency_qd_low, td->latency_qd, td->latency_qd_high);
/*
* When we ramp QD down, quiesce existing IO to prevent
* a storm of ramp downs due to pending higher depth.
*/
io_u_quiesce(td);
lat_new_cycle(td);
return 0;
}
static void lat_target_success(struct thread_data *td)
{
const unsigned int qd = td->latency_qd;
struct thread_options *o = &td->o;
td->latency_qd_low = td->latency_qd;
/*
* If we haven't failed yet, we double up to a failing value instead
* of bisecting from highest possible queue depth. If we have set
* a limit other than td->o.iodepth, bisect between that.
*/
if (td->latency_qd_high != o->iodepth)
td->latency_qd = (td->latency_qd + td->latency_qd_high) / 2;
else
td->latency_qd *= 2;
if (td->latency_qd > o->iodepth)
td->latency_qd = o->iodepth;
dprint(FD_RATE, "Ramped up: %d %d %d\n", td->latency_qd_low, td->latency_qd, td->latency_qd_high);
/*
* Same as last one, we are done. Let it run a latency cycle, so
* we get only the results from the targeted depth.
*/
if (td->latency_qd == qd) {
if (td->latency_end_run) {
dprint(FD_RATE, "We are done\n");
td->done = 1;
} else {
dprint(FD_RATE, "Quiesce and final run\n");
io_u_quiesce(td);
td->latency_end_run = 1;
reset_all_stats(td);
reset_io_stats(td);
}
}
lat_new_cycle(td);
}
