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;
}
/*
* The fiopsd->service_trees holds all pending fiops_ioc's that have
* requests waiting to be processed. It is sorted in the order that
* we will service the queues.
*/
static void fiops_service_tree_add(struct fiops_data *fiopsd,
struct fiops_ioc *ioc)
{
struct rb_node **p, *parent;
struct fiops_ioc *__ioc;
struct fiops_rb_root *service_tree = ioc_service_tree(ioc);
u64 vios;
int left;
/* New added IOC */
if (RB_EMPTY_NODE(&ioc->rb_node)) {
if (ioc->in_flight > 0)
vios = ioc->vios;
else
vios = max_vios(service_tree->min_vios, ioc->vios);
} else {
vios = ioc->vios;
/* ioc->service_tree might not equal to service_tree */
fiops_rb_erase(&ioc->rb_node, ioc->service_tree);
ioc->service_tree = NULL;
}
fiops_log_ioc(fiopsd, ioc, "service tree add, vios %lld", vios);
left = 1;
parent = NULL;
ioc->service_tree = service_tree;
p = &service_tree->rb.rb_node;
while (*p) {
struct rb_node **n;
parent = *p;
__ioc = rb_entry(parent, struct fiops_ioc, rb_node);
/*
* sort by key, that represents service time.
*/
if (vios < __ioc->vios)
n = &(*p)->rb_left;
else {
n = &(*p)->rb_right;
left = 0;
}
p = n;
}
if (left)
service_tree->left = &ioc->rb_node;
ioc->vios = vios;
rb_link_node(&ioc->rb_node, parent, p);
rb_insert_color(&ioc->rb_node, &service_tree->rb);
service_tree->count++;
fiops_update_min_vios(service_tree);
}
static void fiops_completed_request(struct request_queue *q, struct request *rq)
{
struct fiops_data *fiopsd = q->elevator->elevator_data;
struct fiops_ioc *ioc = RQ_CIC(rq);
fiopsd->in_flight[rq_is_sync(rq)]--;
ioc->in_flight--;
fiops_log_ioc(fiopsd, ioc, "in_flight %d, busy queues %d",
ioc->in_flight, fiopsd->busy_queues);
if (fiopsd->in_flight[0] + fiopsd->in_flight[1] == 0)
fiops_schedule_dispatch(fiopsd);
}
static void fiops_charge_vios(struct fiops_data *fiopsd,
struct fiops_ioc *ioc, u64 vios)
{
struct fiops_rb_root *service_tree = ioc->service_tree;
ioc->vios += vios;
fiops_log_ioc(fiopsd, ioc, "charge vios %lld, new vios %lld", vios, ioc->vios);
if (RB_EMPTY_ROOT(&ioc->sort_list))
fiops_del_ioc_rr(fiopsd, ioc);
else
fiops_resort_rr_list(fiopsd, ioc);
fiops_update_min_vios(service_tree);
}