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-rw-r--r--block/cfq-iosched.c134
1 files changed, 126 insertions, 8 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index bc076f45ca4..175218d66d6 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -223,10 +223,21 @@ struct cfq_group {
/* group service_tree key */
u64 vdisktime;
+
+ /*
+ * There are two weights - (internal) weight is the weight of this
+ * cfqg against the sibling cfqgs. leaf_weight is the wight of
+ * this cfqg against the child cfqgs. For the root cfqg, both
+ * weights are kept in sync for backward compatibility.
+ */
unsigned int weight;
unsigned int new_weight;
unsigned int dev_weight;
+ unsigned int leaf_weight;
+ unsigned int new_leaf_weight;
+ unsigned int dev_leaf_weight;
+
/* number of cfqq currently on this group */
int nr_cfqq;
@@ -1182,10 +1193,16 @@ static void
cfq_update_group_weight(struct cfq_group *cfqg)
{
BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node));
+
if (cfqg->new_weight) {
cfqg->weight = cfqg->new_weight;
cfqg->new_weight = 0;
}
+
+ if (cfqg->new_leaf_weight) {
+ cfqg->leaf_weight = cfqg->new_leaf_weight;
+ cfqg->new_leaf_weight = 0;
+ }
}
static void
@@ -1348,6 +1365,7 @@ static void cfq_pd_init(struct blkcg_gq *blkg)
cfq_init_cfqg_base(cfqg);
cfqg->weight = blkg->blkcg->cfq_weight;
+ cfqg->leaf_weight = blkg->blkcg->cfq_leaf_weight;
}
/*
@@ -1404,6 +1422,26 @@ static int cfqg_print_weight_device(struct cgroup *cgrp, struct cftype *cft,
return 0;
}
+static u64 cfqg_prfill_leaf_weight_device(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
+
+ if (!cfqg->dev_leaf_weight)
+ return 0;
+ return __blkg_prfill_u64(sf, pd, cfqg->dev_leaf_weight);
+}
+
+static int cfqg_print_leaf_weight_device(struct cgroup *cgrp,
+ struct cftype *cft,
+ struct seq_file *sf)
+{
+ blkcg_print_blkgs(sf, cgroup_to_blkcg(cgrp),
+ cfqg_prfill_leaf_weight_device, &blkcg_policy_cfq, 0,
+ false);
+ return 0;
+}
+
static int cfq_print_weight(struct cgroup *cgrp, struct cftype *cft,
struct seq_file *sf)
{
@@ -1411,8 +1449,16 @@ static int cfq_print_weight(struct cgroup *cgrp, struct cftype *cft,
return 0;
}
-static int cfqg_set_weight_device(struct cgroup *cgrp, struct cftype *cft,
- const char *buf)
+static int cfq_print_leaf_weight(struct cgroup *cgrp, struct cftype *cft,
+ struct seq_file *sf)
+{
+ seq_printf(sf, "%u\n",
+ cgroup_to_blkcg(cgrp)->cfq_leaf_weight);
+ return 0;
+}
+
+static int __cfqg_set_weight_device(struct cgroup *cgrp, struct cftype *cft,
+ const char *buf, bool is_leaf_weight)
{
struct blkcg *blkcg = cgroup_to_blkcg(cgrp);
struct blkg_conf_ctx ctx;
@@ -1426,8 +1472,13 @@ static int cfqg_set_weight_device(struct cgroup *cgrp, struct cftype *cft,
ret = -EINVAL;
cfqg = blkg_to_cfqg(ctx.blkg);
if (!ctx.v || (ctx.v >= CFQ_WEIGHT_MIN && ctx.v <= CFQ_WEIGHT_MAX)) {
- cfqg->dev_weight = ctx.v;
- cfqg->new_weight = cfqg->dev_weight ?: blkcg->cfq_weight;
+ if (!is_leaf_weight) {
+ cfqg->dev_weight = ctx.v;
+ cfqg->new_weight = ctx.v ?: blkcg->cfq_weight;
+ } else {
+ cfqg->dev_leaf_weight = ctx.v;
+ cfqg->new_leaf_weight = ctx.v ?: blkcg->cfq_leaf_weight;
+ }
ret = 0;
}
@@ -1435,7 +1486,20 @@ static int cfqg_set_weight_device(struct cgroup *cgrp, struct cftype *cft,
return ret;
}
-static int cfq_set_weight(struct cgroup *cgrp, struct cftype *cft, u64 val)
+static int cfqg_set_weight_device(struct cgroup *cgrp, struct cftype *cft,
+ const char *buf)
+{
+ return __cfqg_set_weight_device(cgrp, cft, buf, false);
+}
+
+static int cfqg_set_leaf_weight_device(struct cgroup *cgrp, struct cftype *cft,
+ const char *buf)
+{
+ return __cfqg_set_weight_device(cgrp, cft, buf, true);
+}
+
+static int __cfq_set_weight(struct cgroup *cgrp, struct cftype *cft, u64 val,
+ bool is_leaf_weight)
{
struct blkcg *blkcg = cgroup_to_blkcg(cgrp);
struct blkcg_gq *blkg;
@@ -1445,19 +1509,41 @@ static int cfq_set_weight(struct cgroup *cgrp, struct cftype *cft, u64 val)
return -EINVAL;
spin_lock_irq(&blkcg->lock);
- blkcg->cfq_weight = (unsigned int)val;
+
+ if (!is_leaf_weight)
+ blkcg->cfq_weight = val;
+ else
+ blkcg->cfq_leaf_weight = val;
hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
struct cfq_group *cfqg = blkg_to_cfqg(blkg);
- if (cfqg && !cfqg->dev_weight)
- cfqg->new_weight = blkcg->cfq_weight;
+ if (!cfqg)
+ continue;
+
+ if (!is_leaf_weight) {
+ if (!cfqg->dev_weight)
+ cfqg->new_weight = blkcg->cfq_weight;
+ } else {
+ if (!cfqg->dev_leaf_weight)
+ cfqg->new_leaf_weight = blkcg->cfq_leaf_weight;
+ }
}
spin_unlock_irq(&blkcg->lock);
return 0;
}
+static int cfq_set_weight(struct cgroup *cgrp, struct cftype *cft, u64 val)
+{
+ return __cfq_set_weight(cgrp, cft, val, false);
+}
+
+static int cfq_set_leaf_weight(struct cgroup *cgrp, struct cftype *cft, u64 val)
+{
+ return __cfq_set_weight(cgrp, cft, val, true);
+}
+
static int cfqg_print_stat(struct cgroup *cgrp, struct cftype *cft,
struct seq_file *sf)
{
@@ -1518,6 +1604,37 @@ static struct cftype cfq_blkcg_files[] = {
.read_seq_string = cfq_print_weight,
.write_u64 = cfq_set_weight,
},
+
+ /* on root, leaf_weight is mapped to weight */
+ {
+ .name = "leaf_weight_device",
+ .flags = CFTYPE_ONLY_ON_ROOT,
+ .read_seq_string = cfqg_print_weight_device,
+ .write_string = cfqg_set_weight_device,
+ .max_write_len = 256,
+ },
+ {
+ .name = "leaf_weight",
+ .flags = CFTYPE_ONLY_ON_ROOT,
+ .read_seq_string = cfq_print_weight,
+ .write_u64 = cfq_set_weight,
+ },
+
+ /* no such mapping necessary for !roots */
+ {
+ .name = "leaf_weight_device",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .read_seq_string = cfqg_print_leaf_weight_device,
+ .write_string = cfqg_set_leaf_weight_device,
+ .max_write_len = 256,
+ },
+ {
+ .name = "leaf_weight",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .read_seq_string = cfq_print_leaf_weight,
+ .write_u64 = cfq_set_leaf_weight,
+ },
+
{
.name = "time",
.private = offsetof(struct cfq_group, stats.time),
@@ -3992,6 +4109,7 @@ static int cfq_init_queue(struct request_queue *q)
cfq_init_cfqg_base(cfqd->root_group);
#endif
cfqd->root_group->weight = 2 * CFQ_WEIGHT_DEFAULT;
+ cfqd->root_group->leaf_weight = 2 * CFQ_WEIGHT_DEFAULT;
/*
* Not strictly needed (since RB_ROOT just clears the node and we