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-rw-r--r--block/cfq-iosched.c629
1 files changed, 511 insertions, 118 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index ec52807cdd09..4f0ade74cfd0 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -85,7 +85,6 @@ struct cfq_rb_root {
struct rb_root rb;
struct rb_node *left;
unsigned count;
- unsigned total_weight;
u64 min_vdisktime;
struct cfq_ttime ttime;
};
@@ -155,7 +154,7 @@ struct cfq_queue {
* First index in the service_trees.
* IDLE is handled separately, so it has negative index
*/
-enum wl_prio_t {
+enum wl_class_t {
BE_WORKLOAD = 0,
RT_WORKLOAD = 1,
IDLE_WORKLOAD = 2,
@@ -223,10 +222,45 @@ struct cfq_group {
/* group service_tree key */
u64 vdisktime;
+
+ /*
+ * The number of active cfqgs and sum of their weights under this
+ * cfqg. This covers this cfqg's leaf_weight and all children's
+ * weights, but does not cover weights of further descendants.
+ *
+ * If a cfqg is on the service tree, it's active. An active cfqg
+ * also activates its parent and contributes to the children_weight
+ * of the parent.
+ */
+ int nr_active;
+ unsigned int children_weight;
+
+ /*
+ * vfraction is the fraction of vdisktime that the tasks in this
+ * cfqg are entitled to. This is determined by compounding the
+ * ratios walking up from this cfqg to the root.
+ *
+ * It is in fixed point w/ CFQ_SERVICE_SHIFT and the sum of all
+ * vfractions on a service tree is approximately 1. The sum may
+ * deviate a bit due to rounding errors and fluctuations caused by
+ * cfqgs entering and leaving the service tree.
+ */
+ unsigned int vfraction;
+
+ /*
+ * 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;
@@ -248,14 +282,15 @@ struct cfq_group {
struct cfq_rb_root service_trees[2][3];
struct cfq_rb_root service_tree_idle;
- unsigned long saved_workload_slice;
- enum wl_type_t saved_workload;
- enum wl_prio_t saved_serving_prio;
+ unsigned long saved_wl_slice;
+ enum wl_type_t saved_wl_type;
+ enum wl_class_t saved_wl_class;
/* number of requests that are on the dispatch list or inside driver */
int dispatched;
struct cfq_ttime ttime;
- struct cfqg_stats stats;
+ struct cfqg_stats stats; /* stats for this cfqg */
+ struct cfqg_stats dead_stats; /* stats pushed from dead children */
};
struct cfq_io_cq {
@@ -280,8 +315,8 @@ struct cfq_data {
/*
* The priority currently being served
*/
- enum wl_prio_t serving_prio;
- enum wl_type_t serving_type;
+ enum wl_class_t serving_wl_class;
+ enum wl_type_t serving_wl_type;
unsigned long workload_expires;
struct cfq_group *serving_group;
@@ -353,17 +388,17 @@ struct cfq_data {
static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd);
-static struct cfq_rb_root *service_tree_for(struct cfq_group *cfqg,
- enum wl_prio_t prio,
+static struct cfq_rb_root *st_for(struct cfq_group *cfqg,
+ enum wl_class_t class,
enum wl_type_t type)
{
if (!cfqg)
return NULL;
- if (prio == IDLE_WORKLOAD)
+ if (class == IDLE_WORKLOAD)
return &cfqg->service_tree_idle;
- return &cfqg->service_trees[prio][type];
+ return &cfqg->service_trees[class][type];
}
enum cfqq_state_flags {
@@ -502,7 +537,7 @@ static void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg)
{
struct cfqg_stats *stats = &cfqg->stats;
- if (blkg_rwstat_sum(&stats->queued))
+ if (blkg_rwstat_total(&stats->queued))
return;
/*
@@ -546,7 +581,7 @@ static void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg)
struct cfqg_stats *stats = &cfqg->stats;
blkg_stat_add(&stats->avg_queue_size_sum,
- blkg_rwstat_sum(&stats->queued));
+ blkg_rwstat_total(&stats->queued));
blkg_stat_add(&stats->avg_queue_size_samples, 1);
cfqg_stats_update_group_wait_time(stats);
}
@@ -572,6 +607,13 @@ static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg)
return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq));
}
+static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg)
+{
+ struct blkcg_gq *pblkg = cfqg_to_blkg(cfqg)->parent;
+
+ return pblkg ? blkg_to_cfqg(pblkg) : NULL;
+}
+
static inline void cfqg_get(struct cfq_group *cfqg)
{
return blkg_get(cfqg_to_blkg(cfqg));
@@ -586,8 +628,9 @@ static inline void cfqg_put(struct cfq_group *cfqg)
char __pbuf[128]; \
\
blkg_path(cfqg_to_blkg((cfqq)->cfqg), __pbuf, sizeof(__pbuf)); \
- blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \
- cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
+ blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c %s " fmt, (cfqq)->pid, \
+ cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
+ cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\
__pbuf, ##args); \
} while (0)
@@ -646,11 +689,9 @@ static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
io_start_time - start_time);
}
-static void cfq_pd_reset_stats(struct blkcg_gq *blkg)
+/* @stats = 0 */
+static void cfqg_stats_reset(struct cfqg_stats *stats)
{
- struct cfq_group *cfqg = blkg_to_cfqg(blkg);
- struct cfqg_stats *stats = &cfqg->stats;
-
/* queued stats shouldn't be cleared */
blkg_rwstat_reset(&stats->service_bytes);
blkg_rwstat_reset(&stats->serviced);
@@ -669,13 +710,58 @@ static void cfq_pd_reset_stats(struct blkcg_gq *blkg)
#endif
}
+/* @to += @from */
+static void cfqg_stats_merge(struct cfqg_stats *to, struct cfqg_stats *from)
+{
+ /* queued stats shouldn't be cleared */
+ blkg_rwstat_merge(&to->service_bytes, &from->service_bytes);
+ blkg_rwstat_merge(&to->serviced, &from->serviced);
+ blkg_rwstat_merge(&to->merged, &from->merged);
+ blkg_rwstat_merge(&to->service_time, &from->service_time);
+ blkg_rwstat_merge(&to->wait_time, &from->wait_time);
+ blkg_stat_merge(&from->time, &from->time);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ blkg_stat_merge(&to->unaccounted_time, &from->unaccounted_time);
+ blkg_stat_merge(&to->avg_queue_size_sum, &from->avg_queue_size_sum);
+ blkg_stat_merge(&to->avg_queue_size_samples, &from->avg_queue_size_samples);
+ blkg_stat_merge(&to->dequeue, &from->dequeue);
+ blkg_stat_merge(&to->group_wait_time, &from->group_wait_time);
+ blkg_stat_merge(&to->idle_time, &from->idle_time);
+ blkg_stat_merge(&to->empty_time, &from->empty_time);
+#endif
+}
+
+/*
+ * Transfer @cfqg's stats to its parent's dead_stats so that the ancestors'
+ * recursive stats can still account for the amount used by this cfqg after
+ * it's gone.
+ */
+static void cfqg_stats_xfer_dead(struct cfq_group *cfqg)
+{
+ struct cfq_group *parent = cfqg_parent(cfqg);
+
+ lockdep_assert_held(cfqg_to_blkg(cfqg)->q->queue_lock);
+
+ if (unlikely(!parent))
+ return;
+
+ cfqg_stats_merge(&parent->dead_stats, &cfqg->stats);
+ cfqg_stats_merge(&parent->dead_stats, &cfqg->dead_stats);
+ cfqg_stats_reset(&cfqg->stats);
+ cfqg_stats_reset(&cfqg->dead_stats);
+}
+
#else /* CONFIG_CFQ_GROUP_IOSCHED */
+static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) { return NULL; }
static inline void cfqg_get(struct cfq_group *cfqg) { }
static inline void cfqg_put(struct cfq_group *cfqg) { }
#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \
- blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args)
+ blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c " fmt, (cfqq)->pid, \
+ cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
+ cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\
+ ##args)
#define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0)
static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg,
@@ -732,7 +818,7 @@ static inline bool iops_mode(struct cfq_data *cfqd)
return false;
}
-static inline enum wl_prio_t cfqq_prio(struct cfq_queue *cfqq)
+static inline enum wl_class_t cfqq_class(struct cfq_queue *cfqq)
{
if (cfq_class_idle(cfqq))
return IDLE_WORKLOAD;
@@ -751,23 +837,23 @@ static enum wl_type_t cfqq_type(struct cfq_queue *cfqq)
return SYNC_WORKLOAD;
}
-static inline int cfq_group_busy_queues_wl(enum wl_prio_t wl,
+static inline int cfq_group_busy_queues_wl(enum wl_class_t wl_class,
struct cfq_data *cfqd,
struct cfq_group *cfqg)
{
- if (wl == IDLE_WORKLOAD)
+ if (wl_class == IDLE_WORKLOAD)
return cfqg->service_tree_idle.count;
- return cfqg->service_trees[wl][ASYNC_WORKLOAD].count
- + cfqg->service_trees[wl][SYNC_NOIDLE_WORKLOAD].count
- + cfqg->service_trees[wl][SYNC_WORKLOAD].count;
+ return cfqg->service_trees[wl_class][ASYNC_WORKLOAD].count +
+ cfqg->service_trees[wl_class][SYNC_NOIDLE_WORKLOAD].count +
+ cfqg->service_trees[wl_class][SYNC_WORKLOAD].count;
}
static inline int cfqg_busy_async_queues(struct cfq_data *cfqd,
struct cfq_group *cfqg)
{
- return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count
- + cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count;
+ return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count +
+ cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count;
}
static void cfq_dispatch_insert(struct request_queue *, struct request *);
@@ -847,13 +933,27 @@ cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq)
return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio);
}
-static inline u64 cfq_scale_slice(unsigned long delta, struct cfq_group *cfqg)
+/**
+ * cfqg_scale_charge - scale disk time charge according to cfqg weight
+ * @charge: disk time being charged
+ * @vfraction: vfraction of the cfqg, fixed point w/ CFQ_SERVICE_SHIFT
+ *
+ * Scale @charge according to @vfraction, which is in range (0, 1]. The
+ * scaling is inversely proportional.
+ *
+ * scaled = charge / vfraction
+ *
+ * The result is also in fixed point w/ CFQ_SERVICE_SHIFT.
+ */
+static inline u64 cfqg_scale_charge(unsigned long charge,
+ unsigned int vfraction)
{
- u64 d = delta << CFQ_SERVICE_SHIFT;
+ u64 c = charge << CFQ_SERVICE_SHIFT; /* make it fixed point */
- d = d * CFQ_WEIGHT_DEFAULT;
- do_div(d, cfqg->weight);
- return d;
+ /* charge / vfraction */
+ c <<= CFQ_SERVICE_SHIFT;
+ do_div(c, vfraction);
+ return c;
}
static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime)
@@ -909,9 +1009,7 @@ static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd,
static inline unsigned
cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg)
{
- struct cfq_rb_root *st = &cfqd->grp_service_tree;
-
- return cfqd->cfq_target_latency * cfqg->weight / st->total_weight;
+ return cfqd->cfq_target_latency * cfqg->vfraction >> CFQ_SERVICE_SHIFT;
}
static inline unsigned
@@ -1178,20 +1276,61 @@ 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
cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
{
+ unsigned int vfr = 1 << CFQ_SERVICE_SHIFT; /* start with 1 */
+ struct cfq_group *pos = cfqg;
+ struct cfq_group *parent;
+ bool propagate;
+
+ /* add to the service tree */
BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node));
cfq_update_group_weight(cfqg);
__cfq_group_service_tree_add(st, cfqg);
- st->total_weight += cfqg->weight;
+
+ /*
+ * Activate @cfqg and calculate the portion of vfraction @cfqg is
+ * entitled to. vfraction is calculated by walking the tree
+ * towards the root calculating the fraction it has at each level.
+ * The compounded ratio is how much vfraction @cfqg owns.
+ *
+ * Start with the proportion tasks in this cfqg has against active
+ * children cfqgs - its leaf_weight against children_weight.
+ */
+ propagate = !pos->nr_active++;
+ pos->children_weight += pos->leaf_weight;
+ vfr = vfr * pos->leaf_weight / pos->children_weight;
+
+ /*
+ * Compound ->weight walking up the tree. Both activation and
+ * vfraction calculation are done in the same loop. Propagation
+ * stops once an already activated node is met. vfraction
+ * calculation should always continue to the root.
+ */
+ while ((parent = cfqg_parent(pos))) {
+ if (propagate) {
+ propagate = !parent->nr_active++;
+ parent->children_weight += pos->weight;
+ }
+ vfr = vfr * pos->weight / parent->children_weight;
+ pos = parent;
+ }
+
+ cfqg->vfraction = max_t(unsigned, vfr, 1);
}
static void
@@ -1222,7 +1361,32 @@ cfq_group_notify_queue_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
static void
cfq_group_service_tree_del(struct cfq_rb_root *st, struct cfq_group *cfqg)
{
- st->total_weight -= cfqg->weight;
+ struct cfq_group *pos = cfqg;
+ bool propagate;
+
+ /*
+ * Undo activation from cfq_group_service_tree_add(). Deactivate
+ * @cfqg and propagate deactivation upwards.
+ */
+ propagate = !--pos->nr_active;
+ pos->children_weight -= pos->leaf_weight;
+
+ while (propagate) {
+ struct cfq_group *parent = cfqg_parent(pos);
+
+ /* @pos has 0 nr_active at this point */
+ WARN_ON_ONCE(pos->children_weight);
+ pos->vfraction = 0;
+
+ if (!parent)
+ break;
+
+ propagate = !--parent->nr_active;
+ parent->children_weight -= pos->weight;
+ pos = parent;
+ }
+
+ /* remove from the service tree */
if (!RB_EMPTY_NODE(&cfqg->rb_node))
cfq_rb_erase(&cfqg->rb_node, st);
}
@@ -1241,7 +1405,7 @@ cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
cfq_group_service_tree_del(st, cfqg);
- cfqg->saved_workload_slice = 0;
+ cfqg->saved_wl_slice = 0;
cfqg_stats_update_dequeue(cfqg);
}
@@ -1284,6 +1448,7 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
unsigned int used_sl, charge, unaccounted_sl = 0;
int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg)
- cfqg->service_tree_idle.count;
+ unsigned int vfr;
BUG_ON(nr_sync < 0);
used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl);
@@ -1293,20 +1458,25 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
else if (!cfq_cfqq_sync(cfqq) && !nr_sync)
charge = cfqq->allocated_slice;
- /* Can't update vdisktime while group is on service tree */
+ /*
+ * Can't update vdisktime while on service tree and cfqg->vfraction
+ * is valid only while on it. Cache vfr, leave the service tree,
+ * update vdisktime and go back on. The re-addition to the tree
+ * will also update the weights as necessary.
+ */
+ vfr = cfqg->vfraction;
cfq_group_service_tree_del(st, cfqg);
- cfqg->vdisktime += cfq_scale_slice(charge, cfqg);
- /* If a new weight was requested, update now, off tree */
+ cfqg->vdisktime += cfqg_scale_charge(charge, vfr);
cfq_group_service_tree_add(st, cfqg);
/* This group is being expired. Save the context */
if (time_after(cfqd->workload_expires, jiffies)) {
- cfqg->saved_workload_slice = cfqd->workload_expires
+ cfqg->saved_wl_slice = cfqd->workload_expires
- jiffies;
- cfqg->saved_workload = cfqd->serving_type;
- cfqg->saved_serving_prio = cfqd->serving_prio;
+ cfqg->saved_wl_type = cfqd->serving_wl_type;
+ cfqg->saved_wl_class = cfqd->serving_wl_class;
} else
- cfqg->saved_workload_slice = 0;
+ cfqg->saved_wl_slice = 0;
cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
st->min_vdisktime);
@@ -1344,6 +1514,52 @@ 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;
+}
+
+static void cfq_pd_offline(struct blkcg_gq *blkg)
+{
+ /*
+ * @blkg is going offline and will be ignored by
+ * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so
+ * that they don't get lost. If IOs complete after this point, the
+ * stats for them will be lost. Oh well...
+ */
+ cfqg_stats_xfer_dead(blkg_to_cfqg(blkg));
+}
+
+/* offset delta from cfqg->stats to cfqg->dead_stats */
+static const int dead_stats_off_delta = offsetof(struct cfq_group, dead_stats) -
+ offsetof(struct cfq_group, stats);
+
+/* to be used by recursive prfill, sums live and dead stats recursively */
+static u64 cfqg_stat_pd_recursive_sum(struct blkg_policy_data *pd, int off)
+{
+ u64 sum = 0;
+
+ sum += blkg_stat_recursive_sum(pd, off);
+ sum += blkg_stat_recursive_sum(pd, off + dead_stats_off_delta);
+ return sum;
+}
+
+/* to be used by recursive prfill, sums live and dead rwstats recursively */
+static struct blkg_rwstat cfqg_rwstat_pd_recursive_sum(struct blkg_policy_data *pd,
+ int off)
+{
+ struct blkg_rwstat a, b;
+
+ a = blkg_rwstat_recursive_sum(pd, off);
+ b = blkg_rwstat_recursive_sum(pd, off + dead_stats_off_delta);
+ blkg_rwstat_merge(&a, &b);
+ return a;
+}
+
+static void cfq_pd_reset_stats(struct blkcg_gq *blkg)
+{
+ struct cfq_group *cfqg = blkg_to_cfqg(blkg);
+
+ cfqg_stats_reset(&cfqg->stats);
+ cfqg_stats_reset(&cfqg->dead_stats);
}
/*
@@ -1400,6 +1616,26 @@ 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)
{
@@ -1407,8 +1643,16 @@ 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;
@@ -1422,8 +1666,13 @@ 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;
}
@@ -1431,7 +1680,20 @@ 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;
@@ -1440,19 +1702,41 @@ 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, &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)
{
@@ -1473,6 +1757,42 @@ static int cfqg_print_rwstat(struct cgroup *cgrp, struct cftype *cft,
return 0;
}
+static u64 cfqg_prfill_stat_recursive(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ u64 sum = cfqg_stat_pd_recursive_sum(pd, off);
+
+ return __blkg_prfill_u64(sf, pd, sum);
+}
+
+static u64 cfqg_prfill_rwstat_recursive(struct seq_file *sf,
+ struct blkg_policy_data *pd, int off)
+{
+ struct blkg_rwstat sum = cfqg_rwstat_pd_recursive_sum(pd, off);
+
+ return __blkg_prfill_rwstat(sf, pd, &sum);
+}
+
+static int cfqg_print_stat_recursive(struct cgroup *cgrp, struct cftype *cft,
+ struct seq_file *sf)
+{
+ struct blkcg *blkcg = cgroup_to_blkcg(cgrp);
+
+ blkcg_print_blkgs(sf, blkcg, cfqg_prfill_stat_recursive,
+ &blkcg_policy_cfq, cft->private, false);
+ return 0;
+}
+
+static int cfqg_print_rwstat_recursive(struct cgroup *cgrp, struct cftype *cft,
+ struct seq_file *sf)
+{
+ struct blkcg *blkcg = cgroup_to_blkcg(cgrp);
+
+ blkcg_print_blkgs(sf, blkcg, cfqg_prfill_rwstat_recursive,
+ &blkcg_policy_cfq, cft->private, true);
+ return 0;
+}
+
#ifdef CONFIG_DEBUG_BLK_CGROUP
static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
@@ -1502,17 +1822,49 @@ static int cfqg_print_avg_queue_size(struct cgroup *cgrp, struct cftype *cft,
#endif /* CONFIG_DEBUG_BLK_CGROUP */
static struct cftype cfq_blkcg_files[] = {
+ /* on root, weight is mapped to leaf_weight */
+ {
+ .name = "weight_device",
+ .flags = CFTYPE_ONLY_ON_ROOT,
+ .read_seq_string = cfqg_print_leaf_weight_device,
+ .write_string = cfqg_set_leaf_weight_device,
+ .max_write_len = 256,
+ },
+ {
+ .name = "weight",
+ .flags = CFTYPE_ONLY_ON_ROOT,
+ .read_seq_string = cfq_print_leaf_weight,
+ .write_u64 = cfq_set_leaf_weight,
+ },
+
+ /* no such mapping necessary for !roots */
{
.name = "weight_device",
+ .flags = CFTYPE_NOT_ON_ROOT,
.read_seq_string = cfqg_print_weight_device,
.write_string = cfqg_set_weight_device,
.max_write_len = 256,
},
{
.name = "weight",
+ .flags = CFTYPE_NOT_ON_ROOT,
.read_seq_string = cfq_print_weight,
.write_u64 = cfq_set_weight,
},
+
+ {
+ .name = "leaf_weight_device",
+ .read_seq_string = cfqg_print_leaf_weight_device,
+ .write_string = cfqg_set_leaf_weight_device,
+ .max_write_len = 256,
+ },
+ {
+ .name = "leaf_weight",
+ .read_seq_string = cfq_print_leaf_weight,
+ .write_u64 = cfq_set_leaf_weight,
+ },
+
+ /* statistics, covers only the tasks in the cfqg */
{
.name = "time",
.private = offsetof(struct cfq_group, stats.time),
@@ -1553,6 +1905,48 @@ static struct cftype cfq_blkcg_files[] = {
.private = offsetof(struct cfq_group, stats.queued),
.read_seq_string = cfqg_print_rwstat,
},
+
+ /* the same statictics which cover the cfqg and its descendants */
+ {
+ .name = "time_recursive",
+ .private = offsetof(struct cfq_group, stats.time),
+ .read_seq_string = cfqg_print_stat_recursive,
+ },
+ {
+ .name = "sectors_recursive",
+ .private = offsetof(struct cfq_group, stats.sectors),
+ .read_seq_string = cfqg_print_stat_recursive,
+ },
+ {
+ .name = "io_service_bytes_recursive",
+ .private = offsetof(struct cfq_group, stats.service_bytes),
+ .read_seq_string = cfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "io_serviced_recursive",
+ .private = offsetof(struct cfq_group, stats.serviced),
+ .read_seq_string = cfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "io_service_time_recursive",
+ .private = offsetof(struct cfq_group, stats.service_time),
+ .read_seq_string = cfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "io_wait_time_recursive",
+ .private = offsetof(struct cfq_group, stats.wait_time),
+ .read_seq_string = cfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "io_merged_recursive",
+ .private = offsetof(struct cfq_group, stats.merged),
+ .read_seq_string = cfqg_print_rwstat_recursive,
+ },
+ {
+ .name = "io_queued_recursive",
+ .private = offsetof(struct cfq_group, stats.queued),
+ .read_seq_string = cfqg_print_rwstat_recursive,
+ },
#ifdef CONFIG_DEBUG_BLK_CGROUP
{
.name = "avg_queue_size",
@@ -1611,15 +2005,14 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
struct rb_node **p, *parent;
struct cfq_queue *__cfqq;
unsigned long rb_key;
- struct cfq_rb_root *service_tree;
+ struct cfq_rb_root *st;
int left;
int new_cfqq = 1;
- service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq),
- cfqq_type(cfqq));
+ st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq));
if (cfq_class_idle(cfqq)) {
rb_key = CFQ_IDLE_DELAY;
- parent = rb_last(&service_tree->rb);
+ parent = rb_last(&st->rb);
if (parent && parent != &cfqq->rb_node) {
__cfqq = rb_entry(parent, struct cfq_queue, rb_node);
rb_key += __cfqq->rb_key;
@@ -1637,7 +2030,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
cfqq->slice_resid = 0;
} else {
rb_key = -HZ;
- __cfqq = cfq_rb_first(service_tree);
+ __cfqq = cfq_rb_first(st);
rb_key += __cfqq ? __cfqq->rb_key : jiffies;
}
@@ -1646,8 +2039,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
/*
* same position, nothing more to do
*/
- if (rb_key == cfqq->rb_key &&
- cfqq->service_tree == service_tree)
+ if (rb_key == cfqq->rb_key && cfqq->service_tree == st)
return;
cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree);
@@ -1656,11 +2048,9 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
left = 1;
parent = NULL;
- cfqq->service_tree = service_tree;
- p = &service_tree->rb.rb_node;
+ cfqq->service_tree = st;
+ p = &st->rb.rb_node;
while (*p) {
- struct rb_node **n;
-
parent = *p;
__cfqq = rb_entry(parent, struct cfq_queue, rb_node);
@@ -1668,22 +2058,20 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
* sort by key, that represents service time.
*/
if (time_before(rb_key, __cfqq->rb_key))
- n = &(*p)->rb_left;
+ p = &parent->rb_left;
else {
- n = &(*p)->rb_right;
+ p = &parent->rb_right;
left = 0;
}
-
- p = n;
}
if (left)
- service_tree->left = &cfqq->rb_node;
+ st->left = &cfqq->rb_node;
cfqq->rb_key = rb_key;
rb_link_node(&cfqq->rb_node, parent, p);
- rb_insert_color(&cfqq->rb_node, &service_tree->rb);
- service_tree->count++;
+ rb_insert_color(&cfqq->rb_node, &st->rb);
+ st->count++;
if (add_front || !new_cfqq)
return;
cfq_group_notify_queue_add(cfqd, cfqq->cfqg);
@@ -2029,8 +2417,8 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd,
struct cfq_queue *cfqq)
{
if (cfqq) {
- cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d",
- cfqd->serving_prio, cfqd->serving_type);
+ cfq_log_cfqq(cfqd, cfqq, "set_active wl_class:%d wl_type:%d",
+ cfqd->serving_wl_class, cfqd->serving_wl_type);
cfqg_stats_update_avg_queue_size(cfqq->cfqg);
cfqq->slice_start = 0;
cfqq->dispatch_start = jiffies;
@@ -2116,19 +2504,18 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out)
*/
static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
{
- struct cfq_rb_root *service_tree =
- service_tree_for(cfqd->serving_group, cfqd->serving_prio,
- cfqd->serving_type);
+ struct cfq_rb_root *st = st_for(cfqd->serving_group,
+ cfqd->serving_wl_class, cfqd->serving_wl_type);
if (!cfqd->rq_queued)
return NULL;
/* There is nothing to dispatch */
- if (!service_tree)
+ if (!st)
return NULL;
- if (RB_EMPTY_ROOT(&service_tree->rb))
+ if (RB_EMPTY_ROOT(&st->rb))
return NULL;
- return cfq_rb_first(service_tree);
+ return cfq_rb_first(st);
}
static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd)
@@ -2284,17 +2671,17 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd,
static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
- enum wl_prio_t prio = cfqq_prio(cfqq);
- struct cfq_rb_root *service_tree = cfqq->service_tree;
+ enum wl_class_t wl_class = cfqq_class(cfqq);
+ struct cfq_rb_root *st = cfqq->service_tree;
- BUG_ON(!service_tree);
- BUG_ON(!service_tree->count);
+ BUG_ON(!st);
+ BUG_ON(!st->count);
if (!cfqd->cfq_slice_idle)
return false;
/* We never do for idle class queues. */
- if (prio == IDLE_WORKLOAD)
+ if (wl_class == IDLE_WORKLOAD)
return false;
/* We do for queues that were marked with idle window flag. */
@@ -2306,11 +2693,10 @@ static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
* Otherwise, we do only if they are the last ones
* in their service tree.
*/
- if (service_tree->count == 1 && cfq_cfqq_sync(cfqq) &&
- !cfq_io_thinktime_big(cfqd, &service_tree->ttime, false))
+ if (st->count == 1 && cfq_cfqq_sync(cfqq) &&
+ !cfq_io_thinktime_big(cfqd, &st->ttime, false))
return true;
- cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d",
- service_tree->count);
+ cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", st->count);
return false;
}
@@ -2493,8 +2879,8 @@ static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq)
}
}
-static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd,
- struct cfq_group *cfqg, enum wl_prio_t prio)
+static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd,
+ struct cfq_group *cfqg, enum wl_class_t wl_class)
{
struct cfq_queue *queue;
int i;
@@ -2504,7 +2890,7 @@ static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd,
for (i = 0; i <= SYNC_WORKLOAD; ++i) {
/* select the one with lowest rb_key */
- queue = cfq_rb_first(service_tree_for(cfqg, prio, i));
+ queue = cfq_rb_first(st_for(cfqg, wl_class, i));
if (queue &&
(!key_valid || time_before(queue->rb_key, lowest_key))) {
lowest_key = queue->rb_key;
@@ -2516,26 +2902,27 @@ static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd,
return cur_best;
}
-static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
+static void
+choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg)
{
unsigned slice;
unsigned count;
struct cfq_rb_root *st;
unsigned group_slice;
- enum wl_prio_t original_prio = cfqd->serving_prio;
+ enum wl_class_t original_class = cfqd->serving_wl_class;
/* Choose next priority. RT > BE > IDLE */
if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg))
- cfqd->serving_prio = RT_WORKLOAD;
+ cfqd->serving_wl_class = RT_WORKLOAD;
else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg))
- cfqd->serving_prio = BE_WORKLOAD;
+ cfqd->serving_wl_class = BE_WORKLOAD;
else {
- cfqd->serving_prio = IDLE_WORKLOAD;
+ cfqd->serving_wl_class = IDLE_WORKLOAD;
cfqd->workload_expires = jiffies + 1;
return;
}
- if (original_prio != cfqd->serving_prio)
+ if (original_class != cfqd->serving_wl_class)
goto new_workload;
/*
@@ -2543,7 +2930,7 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
* (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload
* expiration time
*/
- st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type);
+ st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type);
count = st->count;
/*
@@ -2554,9 +2941,9 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
new_workload:
/* otherwise select new workload type */
- cfqd->serving_type =
- cfq_choose_wl(cfqd, cfqg, cfqd->serving_prio);
- st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type);
+ cfqd->serving_wl_type = cfq_choose_wl_type(cfqd, cfqg,
+ cfqd->serving_wl_class);
+ st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type);
count = st->count;
/*
@@ -2567,10 +2954,11 @@ new_workload:
group_slice = cfq_group_slice(cfqd, cfqg);
slice = group_slice * count /
- max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_prio],
- cfq_group_busy_queues_wl(cfqd->serving_prio, cfqd, cfqg));
+ max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_wl_class],
+ cfq_group_busy_queues_wl(cfqd->serving_wl_class, cfqd,
+ cfqg));
- if (cfqd->serving_type == ASYNC_WORKLOAD) {
+ if (cfqd->serving_wl_type == ASYNC_WORKLOAD) {
unsigned int tmp;
/*
@@ -2616,14 +3004,14 @@ static void cfq_choose_cfqg(struct cfq_data *cfqd)
cfqd->serving_group = cfqg;
/* Restore the workload type data */
- if (cfqg->saved_workload_slice) {
- cfqd->workload_expires = jiffies + cfqg->saved_workload_slice;
- cfqd->serving_type = cfqg->saved_workload;
- cfqd->serving_prio = cfqg->saved_serving_prio;
+ if (cfqg->saved_wl_slice) {
+ cfqd->workload_expires = jiffies + cfqg->saved_wl_slice;
+ cfqd->serving_wl_type = cfqg->saved_wl_type;
+ cfqd->serving_wl_class = cfqg->saved_wl_class;
} else
cfqd->workload_expires = jiffies - 1;
- choose_service_tree(cfqd, cfqg);
+ choose_wl_class_and_type(cfqd, cfqg);
}
/*
@@ -3205,6 +3593,8 @@ retry:
spin_lock_irq(cfqd->queue->queue_lock);
if (new_cfqq)
goto retry;
+ else
+ return &cfqd->oom_cfqq;
} else {
cfqq = kmem_cache_alloc_node(cfq_pool,
gfp_mask | __GFP_ZERO,
@@ -3402,7 +3792,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
return true;
/* Allow preemption only if we are idling on sync-noidle tree */
- if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD &&
+ if (cfqd->serving_wl_type == SYNC_NOIDLE_WORKLOAD &&
cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD &&
new_cfqq->service_tree->count == 2 &&
RB_EMPTY_ROOT(&cfqq->sort_list))
@@ -3454,7 +3844,7 @@ static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
* doesn't happen
*/
if (old_type != cfqq_type(cfqq))
- cfqq->cfqg->saved_workload_slice = 0;
+ cfqq->cfqg->saved_wl_slice = 0;
/*
* Put the new queue at the front of the of the current list,
@@ -3636,16 +4026,17 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
if (sync) {
- struct cfq_rb_root *service_tree;
+ struct cfq_rb_root *st;
RQ_CIC(rq)->ttime.last_end_request = now;
if (cfq_cfqq_on_rr(cfqq))
- service_tree = cfqq->service_tree;
+ st = cfqq->service_tree;
else
- service_tree = service_tree_for(cfqq->cfqg,
- cfqq_prio(cfqq), cfqq_type(cfqq));
- service_tree->ttime.last_end_request = now;
+ st = st_for(cfqq->cfqg, cfqq_class(cfqq),
+ cfqq_type(cfqq));
+
+ st->ttime.last_end_request = now;
if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now))
cfqd->last_delayed_sync = now;
}
@@ -3992,6 +4383,7 @@ 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
@@ -4176,6 +4568,7 @@ static struct blkcg_policy blkcg_policy_cfq = {
.cftypes = cfq_blkcg_files,
.pd_init_fn = cfq_pd_init,
+ .pd_offline_fn = cfq_pd_offline,
.pd_reset_stats_fn = cfq_pd_reset_stats,
};
#endif