return -1;
iocg_commit_bio(ctx->iocg, wait->bio, wait->abs_cost, cost);
+ wait->committed = true;
/*
* autoremove_wake_function() removes the wait entry only when it
- * actually changed the task state. We want the wait always
- * removed. Remove explicitly and use default_wake_function().
+ * actually changed the task state. We want the wait always removed.
+ * Remove explicitly and use default_wake_function(). Note that the
+ * order of operations is important as finish_wait() tests whether
+ * @wq_entry is removed without grabbing the lock.
*/
- list_del_init(&wq_entry->entry);
- wait->committed = true;
-
default_wake_function(wq_entry, mode, flags, key);
+ list_del_init_careful(&wq_entry->entry);
return 0;
}
hwm = current_hweight_max(iocg);
new_hwi = hweight_after_donation(iocg, old_hwi, hwm,
usage, &now);
- if (new_hwi < hwm) {
+ /*
+ * Donation calculation assumes hweight_after_donation
+ * to be positive, a condition that a donor w/ hwa < 2
+ * can't meet. Don't bother with donation if hwa is
+ * below 2. It's not gonna make a meaningful difference
+ * anyway.
+ */
+ if (new_hwi < hwm && hwa >= 2) {
iocg->hweight_donating = hwa;
iocg->hweight_after_donation = new_hwi;
list_add(&iocg->surplus_list, &surpluses);
- } else {
+ } else if (!iocg->abs_vdebt) {
+ /*
+ * @iocg doesn't have enough to donate. Reset
+ * its inuse to active.
+ *
+ * Don't reset debtors as their inuse's are
+ * owned by debt handling. This shouldn't affect
+ * donation calculuation in any meaningful way
+ * as @iocg doesn't have a meaningful amount of
+ * share anyway.
+ */
TRACE_IOCG_PATH(inuse_shortage, iocg, &now,
iocg->inuse, iocg->active,
iocg->hweight_inuse, new_hwi);
* called before policy activation completion, can't assume that the
* target bio has an iocg associated and need to test for NULL iocg.
*/
- rq_qos_add(q, rqos);
+ ret = rq_qos_add(q, rqos);
+ if (ret)
+ goto err_free_ioc;
+
ret = blkcg_activate_policy(q, &blkcg_policy_iocost);
- if (ret) {
- rq_qos_del(q, rqos);
- free_percpu(ioc->pcpu_stat);
- kfree(ioc);
- return ret;
- }
+ if (ret)
+ goto err_del_qos;
return 0;
+
+err_del_qos:
+ rq_qos_del(q, rqos);
+err_free_ioc:
+ free_percpu(ioc->pcpu_stat);
+ kfree(ioc);
+ return ret;
}
static struct blkcg_policy_data *ioc_cpd_alloc(gfp_t gfp)
kfree(iocg);
}
-static size_t ioc_pd_stat(struct blkg_policy_data *pd, char *buf, size_t size)
+static bool ioc_pd_stat(struct blkg_policy_data *pd, struct seq_file *s)
{
struct ioc_gq *iocg = pd_to_iocg(pd);
struct ioc *ioc = iocg->ioc;
- size_t pos = 0;
if (!ioc->enabled)
- return 0;
+ return false;
if (iocg->level == 0) {
unsigned vp10k = DIV64_U64_ROUND_CLOSEST(
ioc->vtime_base_rate * 10000,
VTIME_PER_USEC);
- pos += scnprintf(buf + pos, size - pos, " cost.vrate=%u.%02u",
- vp10k / 100, vp10k % 100);
+ seq_printf(s, " cost.vrate=%u.%02u", vp10k / 100, vp10k % 100);
}
- pos += scnprintf(buf + pos, size - pos, " cost.usage=%llu",
- iocg->last_stat.usage_us);
+ seq_printf(s, " cost.usage=%llu", iocg->last_stat.usage_us);
if (blkcg_debug_stats)
- pos += scnprintf(buf + pos, size - pos,
- " cost.wait=%llu cost.indebt=%llu cost.indelay=%llu",
- iocg->last_stat.wait_us,
- iocg->last_stat.indebt_us,
- iocg->last_stat.indelay_us);
-
- return pos;
+ seq_printf(s, " cost.wait=%llu cost.indebt=%llu cost.indelay=%llu",
+ iocg->last_stat.wait_us,
+ iocg->last_stat.indebt_us,
+ iocg->last_stat.indelay_us);
+ return true;
}
static u64 ioc_weight_prfill(struct seq_file *sf, struct blkg_policy_data *pd,
if (v < CGROUP_WEIGHT_MIN || v > CGROUP_WEIGHT_MAX)
return -EINVAL;
- spin_lock(&blkcg->lock);
+ spin_lock_irq(&blkcg->lock);
iocc->dfl_weight = v * WEIGHT_ONE;
hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
struct ioc_gq *iocg = blkg_to_iocg(blkg);
if (iocg) {
- spin_lock_irq(&iocg->ioc->lock);
+ spin_lock(&iocg->ioc->lock);
ioc_now(iocg->ioc, &now);
weight_updated(iocg, &now);
- spin_unlock_irq(&iocg->ioc->lock);
+ spin_unlock(&iocg->ioc->lock);
}
}
- spin_unlock(&blkcg->lock);
+ spin_unlock_irq(&blkcg->lock);
return nbytes;
}