static struct fiops_ioc *fiops_select_ioc(struct fiops_data *fiopsd)
{
struct fiops_ioc *ioc;
struct fiops_rb_root *service_tree = NULL;
int i;
struct request *rq;
for (i = RT_WORKLOAD; i >= IDLE_WORKLOAD; i--) {
if (!RB_EMPTY_ROOT(&fiopsd->service_tree[i].rb)) {
service_tree = &fiopsd->service_tree[i];
break;
}
}
if (!service_tree)
return NULL;
ioc = fiops_rb_first(service_tree);
rq = rq_entry_fifo(ioc->fifo.next);
/*
* we are the only async task and sync requests are in flight, delay a
* moment. If there are other tasks coming, sync tasks have no chance
* to be starved, don't delay
*/
if (!rq_is_sync(rq) && fiopsd->in_flight[1] != 0 &&
service_tree->count == 1) {
fiops_log_ioc(fiopsd, ioc,
"postpone async, in_flight async %d sync %d",
fiopsd->in_flight[0], fiopsd->in_flight[1]);
return NULL;
}
return ioc;
}
static void fiops_update_min_vios(struct fiops_rb_root *service_tree)
{
struct fiops_ioc *ioc;
ioc = fiops_rb_first(service_tree);
if (!ioc)
return;
service_tree->min_vios = max_vios(service_tree->min_vios, ioc->vios);
}
static int fiops_forced_dispatch(struct fiops_data *fiopsd)
{
struct fiops_ioc *ioc;
int dispatched = 0;
int i;
for (i = RT_WORKLOAD; i >= IDLE_WORKLOAD; i--) {
while (!RB_EMPTY_ROOT(&fiopsd->service_tree[i].rb)) {
ioc = fiops_rb_first(&fiopsd->service_tree[i]);
while (!list_empty(&ioc->fifo)) {
fiops_dispatch_request(fiopsd, ioc);
dispatched++;
}
if (fiops_ioc_on_rr(ioc))
fiops_del_ioc_rr(fiopsd, ioc);
}
}
return dispatched;
}