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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-28 12:52:24 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-28 12:52:24 -0800
commitee89f81252179dcbf6cd65bd48299f5e52292d88 (patch)
tree805846cd12821f84cfe619d44c9e3e36e0b0f9e6 /block
parent21f3b24da9328415792efc780f50b9f434c12465 (diff)
parentde33127d8d3f1d570aad8c2223cd81b206636bc1 (diff)
downloadlinux-linaro-stable-ee89f81252179dcbf6cd65bd48299f5e52292d88.tar.gz
Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-block
Pull block IO core bits from Jens Axboe: "Below are the core block IO bits for 3.9. It was delayed a few days since my workstation kept crashing every 2-8h after pulling it into current -git, but turns out it is a bug in the new pstate code (divide by zero, will report separately). In any case, it contains: - The big cfq/blkcg update from Tejun and and Vivek. - Additional block and writeback tracepoints from Tejun. - Improvement of the should sort (based on queues) logic in the plug flushing. - _io() variants of the wait_for_completion() interface, using io_schedule() instead of schedule() to contribute to io wait properly. - Various little fixes. You'll get two trivial merge conflicts, which should be easy enough to fix up" Fix up the trivial conflicts due to hlist traversal cleanups (commit b67bfe0d42ca: "hlist: drop the node parameter from iterators"). * 'for-3.9/core' of git://git.kernel.dk/linux-block: (39 commits) block: remove redundant check to bd_openers() block: use i_size_write() in bd_set_size() cfq: fix lock imbalance with failed allocations drivers/block/swim3.c: fix null pointer dereference block: don't select PERCPU_RWSEM block: account iowait time when waiting for completion of IO request sched: add wait_for_completion_io[_timeout] writeback: add more tracepoints block: add block_{touch|dirty}_buffer tracepoint buffer: make touch_buffer() an exported function block: add @req to bio_{front|back}_merge tracepoints block: add missing block_bio_complete() tracepoint block: Remove should_sort judgement when flush blk_plug block,elevator: use new hashtable implementation cfq-iosched: add hierarchical cfq_group statistics cfq-iosched: collect stats from dead cfqgs cfq-iosched: separate out cfqg_stats_reset() from cfq_pd_reset_stats() blkcg: make blkcg_print_blkgs() grab q locks instead of blkcg lock block: RCU free request_queue blkcg: implement blkg_[rw]stat_recursive_sum() and blkg_[rw]stat_merge() ...
Diffstat (limited to 'block')
-rw-r--r--block/Kconfig1
-rw-r--r--block/blk-cgroup.c277
-rw-r--r--block/blk-cgroup.h68
-rw-r--r--block/blk-core.c18
-rw-r--r--block/blk-exec.c4
-rw-r--r--block/blk-flush.c2
-rw-r--r--block/blk-lib.c6
-rw-r--r--block/blk-sysfs.c9
-rw-r--r--block/blk.h2
-rw-r--r--block/cfq-iosched.c629
-rw-r--r--block/elevator.c23
11 files changed, 834 insertions, 205 deletions
diff --git a/block/Kconfig b/block/Kconfig
index 4a85ccf8d4cf..a7e40a7c8214 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -4,7 +4,6 @@
menuconfig BLOCK
bool "Enable the block layer" if EXPERT
default y
- select PERCPU_RWSEM
help
Provide block layer support for the kernel.
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 8bdebb6781e1..b2b9837f9dd3 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -26,11 +26,32 @@
static DEFINE_MUTEX(blkcg_pol_mutex);
-struct blkcg blkcg_root = { .cfq_weight = 2 * CFQ_WEIGHT_DEFAULT };
+struct blkcg blkcg_root = { .cfq_weight = 2 * CFQ_WEIGHT_DEFAULT,
+ .cfq_leaf_weight = 2 * CFQ_WEIGHT_DEFAULT, };
EXPORT_SYMBOL_GPL(blkcg_root);
static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];
+static struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
+ struct request_queue *q, bool update_hint);
+
+/**
+ * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants
+ * @d_blkg: loop cursor pointing to the current descendant
+ * @pos_cgrp: used for iteration
+ * @p_blkg: target blkg to walk descendants of
+ *
+ * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU
+ * read locked. If called under either blkcg or queue lock, the iteration
+ * is guaranteed to include all and only online blkgs. The caller may
+ * update @pos_cgrp by calling cgroup_rightmost_descendant() to skip
+ * subtree.
+ */
+#define blkg_for_each_descendant_pre(d_blkg, pos_cgrp, p_blkg) \
+ cgroup_for_each_descendant_pre((pos_cgrp), (p_blkg)->blkcg->css.cgroup) \
+ if (((d_blkg) = __blkg_lookup(cgroup_to_blkcg(pos_cgrp), \
+ (p_blkg)->q, false)))
+
static bool blkcg_policy_enabled(struct request_queue *q,
const struct blkcg_policy *pol)
{
@@ -112,9 +133,10 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
blkg->pd[i] = pd;
pd->blkg = blkg;
+ pd->plid = i;
/* invoke per-policy init */
- if (blkcg_policy_enabled(blkg->q, pol))
+ if (pol->pd_init_fn)
pol->pd_init_fn(blkg);
}
@@ -125,8 +147,19 @@ err_free:
return NULL;
}
+/**
+ * __blkg_lookup - internal version of blkg_lookup()
+ * @blkcg: blkcg of interest
+ * @q: request_queue of interest
+ * @update_hint: whether to update lookup hint with the result or not
+ *
+ * This is internal version and shouldn't be used by policy
+ * implementations. Looks up blkgs for the @blkcg - @q pair regardless of
+ * @q's bypass state. If @update_hint is %true, the caller should be
+ * holding @q->queue_lock and lookup hint is updated on success.
+ */
static struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
- struct request_queue *q)
+ struct request_queue *q, bool update_hint)
{
struct blkcg_gq *blkg;
@@ -135,14 +168,19 @@ static struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
return blkg;
/*
- * Hint didn't match. Look up from the radix tree. Note that we
- * may not be holding queue_lock and thus are not sure whether
- * @blkg from blkg_tree has already been removed or not, so we
- * can't update hint to the lookup result. Leave it to the caller.
+ * Hint didn't match. Look up from the radix tree. Note that the
+ * hint can only be updated under queue_lock as otherwise @blkg
+ * could have already been removed from blkg_tree. The caller is
+ * responsible for grabbing queue_lock if @update_hint.
*/
blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id);
- if (blkg && blkg->q == q)
+ if (blkg && blkg->q == q) {
+ if (update_hint) {
+ lockdep_assert_held(q->queue_lock);
+ rcu_assign_pointer(blkcg->blkg_hint, blkg);
+ }
return blkg;
+ }
return NULL;
}
@@ -162,7 +200,7 @@ struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, struct request_queue *q)
if (unlikely(blk_queue_bypass(q)))
return NULL;
- return __blkg_lookup(blkcg, q);
+ return __blkg_lookup(blkcg, q, false);
}
EXPORT_SYMBOL_GPL(blkg_lookup);
@@ -170,75 +208,129 @@ EXPORT_SYMBOL_GPL(blkg_lookup);
* If @new_blkg is %NULL, this function tries to allocate a new one as
* necessary using %GFP_ATOMIC. @new_blkg is always consumed on return.
*/
-static struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,
- struct request_queue *q,
- struct blkcg_gq *new_blkg)
+static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
+ struct request_queue *q,
+ struct blkcg_gq *new_blkg)
{
struct blkcg_gq *blkg;
- int ret;
+ int i, ret;
WARN_ON_ONCE(!rcu_read_lock_held());
lockdep_assert_held(q->queue_lock);
- /* lookup and update hint on success, see __blkg_lookup() for details */
- blkg = __blkg_lookup(blkcg, q);
- if (blkg) {
- rcu_assign_pointer(blkcg->blkg_hint, blkg);
- goto out_free;
- }
-
/* blkg holds a reference to blkcg */
if (!css_tryget(&blkcg->css)) {
- blkg = ERR_PTR(-EINVAL);
- goto out_free;
+ ret = -EINVAL;
+ goto err_free_blkg;
}
/* allocate */
if (!new_blkg) {
new_blkg = blkg_alloc(blkcg, q, GFP_ATOMIC);
if (unlikely(!new_blkg)) {
- blkg = ERR_PTR(-ENOMEM);
- goto out_put;
+ ret = -ENOMEM;
+ goto err_put_css;
}
}
blkg = new_blkg;
- /* insert */
+ /* link parent and insert */
+ if (blkcg_parent(blkcg)) {
+ blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false);
+ if (WARN_ON_ONCE(!blkg->parent)) {
+ blkg = ERR_PTR(-EINVAL);
+ goto err_put_css;
+ }
+ blkg_get(blkg->parent);
+ }
+
spin_lock(&blkcg->lock);
ret = radix_tree_insert(&blkcg->blkg_tree, q->id, blkg);
if (likely(!ret)) {
hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
list_add(&blkg->q_node, &q->blkg_list);
+
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+
+ if (blkg->pd[i] && pol->pd_online_fn)
+ pol->pd_online_fn(blkg);
+ }
}
+ blkg->online = true;
spin_unlock(&blkcg->lock);
if (!ret)
return blkg;
- blkg = ERR_PTR(ret);
-out_put:
+ /* @blkg failed fully initialized, use the usual release path */
+ blkg_put(blkg);
+ return ERR_PTR(ret);
+
+err_put_css:
css_put(&blkcg->css);
-out_free:
+err_free_blkg:
blkg_free(new_blkg);
- return blkg;
+ return ERR_PTR(ret);
}
+/**
+ * blkg_lookup_create - lookup blkg, try to create one if not there
+ * @blkcg: blkcg of interest
+ * @q: request_queue of interest
+ *
+ * Lookup blkg for the @blkcg - @q pair. If it doesn't exist, try to
+ * create one. blkg creation is performed recursively from blkcg_root such
+ * that all non-root blkg's have access to the parent blkg. This function
+ * should be called under RCU read lock and @q->queue_lock.
+ *
+ * Returns pointer to the looked up or created blkg on success, ERR_PTR()
+ * value on error. If @q is dead, returns ERR_PTR(-EINVAL). If @q is not
+ * dead and bypassing, returns ERR_PTR(-EBUSY).
+ */
struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
struct request_queue *q)
{
+ struct blkcg_gq *blkg;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+ lockdep_assert_held(q->queue_lock);
+
/*
* This could be the first entry point of blkcg implementation and
* we shouldn't allow anything to go through for a bypassing queue.
*/
if (unlikely(blk_queue_bypass(q)))
return ERR_PTR(blk_queue_dying(q) ? -EINVAL : -EBUSY);
- return __blkg_lookup_create(blkcg, q, NULL);
+
+ blkg = __blkg_lookup(blkcg, q, true);
+ if (blkg)
+ return blkg;
+
+ /*
+ * Create blkgs walking down from blkcg_root to @blkcg, so that all
+ * non-root blkgs have access to their parents.
+ */
+ while (true) {
+ struct blkcg *pos = blkcg;
+ struct blkcg *parent = blkcg_parent(blkcg);
+
+ while (parent && !__blkg_lookup(parent, q, false)) {
+ pos = parent;
+ parent = blkcg_parent(parent);
+ }
+
+ blkg = blkg_create(pos, q, NULL);
+ if (pos == blkcg || IS_ERR(blkg))
+ return blkg;
+ }
}
EXPORT_SYMBOL_GPL(blkg_lookup_create);
static void blkg_destroy(struct blkcg_gq *blkg)
{
struct blkcg *blkcg = blkg->blkcg;
+ int i;
lockdep_assert_held(blkg->q->queue_lock);
lockdep_assert_held(&blkcg->lock);
@@ -247,6 +339,14 @@ static void blkg_destroy(struct blkcg_gq *blkg)
WARN_ON_ONCE(list_empty(&blkg->q_node));
WARN_ON_ONCE(hlist_unhashed(&blkg->blkcg_node));
+ for (i = 0; i < BLKCG_MAX_POLS; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+
+ if (blkg->pd[i] && pol->pd_offline_fn)
+ pol->pd_offline_fn(blkg);
+ }
+ blkg->online = false;
+
radix_tree_delete(&blkcg->blkg_tree, blkg->q->id);
list_del_init(&blkg->q_node);
hlist_del_init_rcu(&blkg->blkcg_node);
@@ -301,8 +401,10 @@ static void blkg_rcu_free(struct rcu_head *rcu_head)
void __blkg_release(struct blkcg_gq *blkg)
{
- /* release the extra blkcg reference this blkg has been holding */
+ /* release the blkcg and parent blkg refs this blkg has been holding */
css_put(&blkg->blkcg->css);
+ if (blkg->parent)
+ blkg_put(blkg->parent);
/*
* A group is freed in rcu manner. But having an rcu lock does not
@@ -401,8 +503,9 @@ static const char *blkg_dev_name(struct blkcg_gq *blkg)
*
* This function invokes @prfill on each blkg of @blkcg if pd for the
* policy specified by @pol exists. @prfill is invoked with @sf, the
- * policy data and @data. If @show_total is %true, the sum of the return
- * values from @prfill is printed with "Total" label at the end.
+ * policy data and @data and the matching queue lock held. If @show_total
+ * is %true, the sum of the return values from @prfill is printed with
+ * "Total" label at the end.
*
* This is to be used to construct print functions for
* cftype->read_seq_string method.
@@ -416,11 +519,14 @@ void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
struct blkcg_gq *blkg;
u64 total = 0;
- spin_lock_irq(&blkcg->lock);
- hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node)
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
+ spin_lock_irq(blkg->q->queue_lock);
if (blkcg_policy_enabled(blkg->q, pol))
total += prfill(sf, blkg->pd[pol->plid], data);
- spin_unlock_irq(&blkcg->lock);
+ spin_unlock_irq(blkg->q->queue_lock);
+ }
+ rcu_read_unlock();
if (show_total)
seq_printf(sf, "Total %llu\n", (unsigned long long)total);
@@ -479,6 +585,7 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
seq_printf(sf, "%s Total %llu\n", dname, (unsigned long long)v);
return v;
}
+EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat);
/**
* blkg_prfill_stat - prfill callback for blkg_stat
@@ -512,6 +619,82 @@ u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
EXPORT_SYMBOL_GPL(blkg_prfill_rwstat);
/**
+ * blkg_stat_recursive_sum - collect hierarchical blkg_stat
+ * @pd: policy private data of interest
+ * @off: offset to the blkg_stat in @pd
+ *
+ * Collect the blkg_stat specified by @off from @pd and all its online
+ * descendants and return the sum. The caller must be holding the queue
+ * lock for online tests.
+ */
+u64 blkg_stat_recursive_sum(struct blkg_policy_data *pd, int off)
+{
+ struct blkcg_policy *pol = blkcg_policy[pd->plid];
+ struct blkcg_gq *pos_blkg;
+ struct cgroup *pos_cgrp;
+ u64 sum;
+
+ lockdep_assert_held(pd->blkg->q->queue_lock);
+
+ sum = blkg_stat_read((void *)pd + off);
+
+ rcu_read_lock();
+ blkg_for_each_descendant_pre(pos_blkg, pos_cgrp, pd_to_blkg(pd)) {
+ struct blkg_policy_data *pos_pd = blkg_to_pd(pos_blkg, pol);
+ struct blkg_stat *stat = (void *)pos_pd + off;
+
+ if (pos_blkg->online)
+ sum += blkg_stat_read(stat);
+ }
+ rcu_read_unlock();
+
+ return sum;
+}
+EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum);
+
+/**
+ * blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat
+ * @pd: policy private data of interest
+ * @off: offset to the blkg_stat in @pd
+ *
+ * Collect the blkg_rwstat specified by @off from @pd and all its online
+ * descendants and return the sum. The caller must be holding the queue
+ * lock for online tests.
+ */
+struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkg_policy_data *pd,
+ int off)
+{
+ struct blkcg_policy *pol = blkcg_policy[pd->plid];
+ struct blkcg_gq *pos_blkg;
+ struct cgroup *pos_cgrp;
+ struct blkg_rwstat sum;
+ int i;
+
+ lockdep_assert_held(pd->blkg->q->queue_lock);
+
+ sum = blkg_rwstat_read((void *)pd + off);
+
+ rcu_read_lock();
+ blkg_for_each_descendant_pre(pos_blkg, pos_cgrp, pd_to_blkg(pd)) {
+ struct blkg_policy_data *pos_pd = blkg_to_pd(pos_blkg, pol);
+ struct blkg_rwstat *rwstat = (void *)pos_pd + off;
+ struct blkg_rwstat tmp;
+
+ if (!pos_blkg->online)
+ continue;
+
+ tmp = blkg_rwstat_read(rwstat);
+
+ for (i = 0; i < BLKG_RWSTAT_NR; i++)
+ sum.cnt[i] += tmp.cnt[i];
+ }
+ rcu_read_unlock();
+
+ return sum;
+}
+EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum);
+
+/**
* blkg_conf_prep - parse and prepare for per-blkg config update
* @blkcg: target block cgroup
* @pol: target policy
@@ -656,6 +839,7 @@ static struct cgroup_subsys_state *blkcg_css_alloc(struct cgroup *cgroup)
return ERR_PTR(-ENOMEM);
blkcg->cfq_weight = CFQ_WEIGHT_DEFAULT;
+ blkcg->cfq_leaf_weight = CFQ_WEIGHT_DEFAULT;
blkcg->id = atomic64_inc_return(&id_seq); /* root is 0, start from 1 */
done:
spin_lock_init(&blkcg->lock);
@@ -775,7 +959,7 @@ int blkcg_activate_policy(struct request_queue *q,
const struct blkcg_policy *pol)
{
LIST_HEAD(pds);
- struct blkcg_gq *blkg;
+ struct blkcg_gq *blkg, *new_blkg;
struct blkg_policy_data *pd, *n;
int cnt = 0, ret;
bool preloaded;
@@ -784,19 +968,27 @@ int blkcg_activate_policy(struct request_queue *q,
return 0;
/* preallocations for root blkg */
- blkg = blkg_alloc(&blkcg_root, q, GFP_KERNEL);
- if (!blkg)
+ new_blkg = blkg_alloc(&blkcg_root, q, GFP_KERNEL);
+ if (!new_blkg)
return -ENOMEM;
preloaded = !radix_tree_preload(GFP_KERNEL);
blk_queue_bypass_start(q);
- /* make sure the root blkg exists and count the existing blkgs */
+ /*
+ * Make sure the root blkg exists and count the existing blkgs. As
+ * @q is bypassing at this point, blkg_lookup_create() can't be
+ * used. Open code it.
+ */
spin_lock_irq(q->queue_lock);
rcu_read_lock();
- blkg = __blkg_lookup_create(&blkcg_root, q, blkg);
+ blkg = __blkg_lookup(&blkcg_root, q, false);
+ if (blkg)
+ blkg_free(new_blkg);
+ else
+ blkg = blkg_create(&blkcg_root, q, new_blkg);
rcu_read_unlock();
if (preloaded)
@@ -844,6 +1036,7 @@ int blkcg_activate_policy(struct request_queue *q,
blkg->pd[pol->plid] = pd;
pd->blkg = blkg;
+ pd->plid = pol->plid;
pol->pd_init_fn(blkg);
spin_unlock(&blkg->blkcg->lock);
@@ -890,6 +1083,8 @@ void blkcg_deactivate_policy(struct request_queue *q,
/* grab blkcg lock too while removing @pd from @blkg */
spin_lock(&blkg->blkcg->lock);
+ if (pol->pd_offline_fn)
+ pol->pd_offline_fn(blkg);
if (pol->pd_exit_fn)
pol->pd_exit_fn(blkg);
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 24597309e23d..f2b292925ccd 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -54,6 +54,7 @@ struct blkcg {
/* TODO: per-policy storage in blkcg */
unsigned int cfq_weight; /* belongs to cfq */
+ unsigned int cfq_leaf_weight;
};
struct blkg_stat {
@@ -80,8 +81,9 @@ struct blkg_rwstat {
* beginning and pd_size can't be smaller than pd.
*/
struct blkg_policy_data {
- /* the blkg this per-policy data belongs to */
+ /* the blkg and policy id this per-policy data belongs to */
struct blkcg_gq *blkg;
+ int plid;
/* used during policy activation */
struct list_head alloc_node;
@@ -94,17 +96,27 @@ struct blkcg_gq {
struct list_head q_node;
struct hlist_node blkcg_node;
struct blkcg *blkcg;
+
+ /* all non-root blkcg_gq's are guaranteed to have access to parent */
+ struct blkcg_gq *parent;
+
/* request allocation list for this blkcg-q pair */
struct request_list rl;
+
/* reference count */
int refcnt;
+ /* is this blkg online? protected by both blkcg and q locks */
+ bool online;
+
struct blkg_policy_data *pd[BLKCG_MAX_POLS];
struct rcu_head rcu_head;
};
typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg);
+typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg);
+typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_exit_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg);
@@ -117,6 +129,8 @@ struct blkcg_policy {
/* operations */
blkcg_pol_init_pd_fn *pd_init_fn;
+ blkcg_pol_online_pd_fn *pd_online_fn;
+ blkcg_pol_offline_pd_fn *pd_offline_fn;
blkcg_pol_exit_pd_fn *pd_exit_fn;
blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn;
};
@@ -150,6 +164,10 @@ u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off);
u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
int off);
+u64 blkg_stat_recursive_sum(struct blkg_policy_data *pd, int off);
+struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkg_policy_data *pd,
+ int off);
+
struct blkg_conf_ctx {
struct gendisk *disk;
struct blkcg_gq *blkg;
@@ -181,6 +199,19 @@ static inline struct blkcg *bio_blkcg(struct bio *bio)
}
/**
+ * blkcg_parent - get the parent of a blkcg
+ * @blkcg: blkcg of interest
+ *
+ * Return the parent blkcg of @blkcg. Can be called anytime.
+ */
+static inline struct blkcg *blkcg_parent(struct blkcg *blkcg)
+{
+ struct cgroup *pcg = blkcg->css.cgroup->parent;
+
+ return pcg ? cgroup_to_blkcg(pcg) : NULL;
+}
+
+/**
* blkg_to_pdata - get policy private data
* @blkg: blkg of interest
* @pol: policy of interest
@@ -387,6 +418,18 @@ static inline void blkg_stat_reset(struct blkg_stat *stat)
}
/**
+ * blkg_stat_merge - merge a blkg_stat into another
+ * @to: the destination blkg_stat
+ * @from: the source
+ *
+ * Add @from's count to @to.
+ */
+static inline void blkg_stat_merge(struct blkg_stat *to, struct blkg_stat *from)
+{
+ blkg_stat_add(to, blkg_stat_read(from));
+}
+
+/**
* blkg_rwstat_add - add a value to a blkg_rwstat
* @rwstat: target blkg_rwstat
* @rw: mask of REQ_{WRITE|SYNC}
@@ -434,14 +477,14 @@ static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat)
}
/**
- * blkg_rwstat_sum - read the total count of a blkg_rwstat
+ * blkg_rwstat_total - read the total count of a blkg_rwstat
* @rwstat: blkg_rwstat to read
*
* Return the total count of @rwstat regardless of the IO direction. This
* function can be called without synchronization and takes care of u64
* atomicity.
*/
-static inline uint64_t blkg_rwstat_sum(struct blkg_rwstat *rwstat)
+static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat)
{
struct blkg_rwstat tmp = blkg_rwstat_read(rwstat);
@@ -457,6 +500,25 @@ static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat)
memset(rwstat->cnt, 0, sizeof(rwstat->cnt));
}
+/**
+ * blkg_rwstat_merge - merge a blkg_rwstat into another
+ * @to: the destination blkg_rwstat
+ * @from: the source
+ *
+ * Add @from's counts to @to.
+ */
+static inline void blkg_rwstat_merge(struct blkg_rwstat *to,
+ struct blkg_rwstat *from)
+{
+ struct blkg_rwstat v = blkg_rwstat_read(from);
+ int i;
+
+ u64_stats_update_begin(&to->syncp);
+ for (i = 0; i < BLKG_RWSTAT_NR; i++)
+ to->cnt[i] += v.cnt[i];
+ u64_stats_update_end(&to->syncp);
+}
+
#else /* CONFIG_BLK_CGROUP */
struct cgroup;
diff --git a/block/blk-core.c b/block/blk-core.c
index 277134cb5d32..074b758efc42 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -39,7 +39,6 @@
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
-EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
EXPORT_TRACEPOINT_SYMBOL_GPL(block_unplug);
DEFINE_IDA(blk_queue_ida);
@@ -1348,7 +1347,7 @@ static bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
if (!ll_back_merge_fn(q, req, bio))
return false;
- trace_block_bio_backmerge(q, bio);
+ trace_block_bio_backmerge(q, req, bio);
if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
blk_rq_set_mixed_merge(req);
@@ -1370,7 +1369,7 @@ static bool bio_attempt_front_merge(struct request_queue *q,
if (!ll_front_merge_fn(q, req, bio))
return false;
- trace_block_bio_frontmerge(q, bio);
+ trace_block_bio_frontmerge(q, req, bio);
if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
blk_rq_set_mixed_merge(req);
@@ -1553,13 +1552,6 @@ get_rq:
if (list_empty(&plug->list))
trace_block_plug(q);
else {
- if (!plug->should_sort) {
- struct request *__rq;
-
- __rq = list_entry_rq(plug->list.prev);
- if (__rq->q != q)
- plug->should_sort = 1;
- }
if (request_count >= BLK_MAX_REQUEST_COUNT) {
blk_flush_plug_list(plug, false);
trace_block_plug(q);
@@ -2890,7 +2882,6 @@ void blk_start_plug(struct blk_plug *plug)
plug->magic = PLUG_MAGIC;
INIT_LIST_HEAD(&plug->list);
INIT_LIST_HEAD(&plug->cb_list);
- plug->should_sort = 0;
/*
* If this is a nested plug, don't actually assign it. It will be
@@ -2992,10 +2983,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
list_splice_init(&plug->list, &list);
- if (plug->should_sort) {
- list_sort(NULL, &list, plug_rq_cmp);
- plug->should_sort = 0;
- }
+ list_sort(NULL, &list, plug_rq_cmp);
q = NULL;
depth = 0;
diff --git a/block/blk-exec.c b/block/blk-exec.c
index c88202f973d9..e70621396129 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -121,9 +121,9 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
/* Prevent hang_check timer from firing at us during very long I/O */
hang_check = sysctl_hung_task_timeout_secs;
if (hang_check)
- while (!wait_for_completion_timeout(&wait, hang_check * (HZ/2)));
+ while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2)));
else
- wait_for_completion(&wait);
+ wait_for_completion_io(&wait);
if (rq->errors)
err = -EIO;
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 720ad607ff91..db8f1b507857 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -436,7 +436,7 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
bio_get(bio);
submit_bio(WRITE_FLUSH, bio);
- wait_for_completion(&wait);
+ wait_for_completion_io(&wait);
/*
* The driver must store the error location in ->bi_sector, if
diff --git a/block/blk-lib.c b/block/blk-lib.c
index b3a1f2b70b31..d6f50d572565 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -126,7 +126,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
/* Wait for bios in-flight */
if (!atomic_dec_and_test(&bb.done))
- wait_for_completion(&wait);
+ wait_for_completion_io(&wait);
if (!test_bit(BIO_UPTODATE, &bb.flags))
ret = -EIO;
@@ -200,7 +200,7 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
/* Wait for bios in-flight */
if (!atomic_dec_and_test(&bb.done))
- wait_for_completion(&wait);
+ wait_for_completion_io(&wait);
if (!test_bit(BIO_UPTODATE, &bb.flags))
ret = -ENOTSUPP;
@@ -262,7 +262,7 @@ int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
/* Wait for bios in-flight */
if (!atomic_dec_and_test(&bb.done))
- wait_for_completion(&wait);
+ wait_for_completion_io(&wait);
if (!test_bit(BIO_UPTODATE, &bb.flags))
/* One of bios in the batch was completed with error.*/
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 788147797a79..6206a934eb8c 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -497,6 +497,13 @@ queue_attr_store(struct kobject *kobj, struct attribute *attr,
return res;
}
+static void blk_free_queue_rcu(struct rcu_head *rcu_head)
+{
+ struct request_queue *q = container_of(rcu_head, struct request_queue,
+ rcu_head);
+ kmem_cache_free(blk_requestq_cachep, q);
+}
+
/**
* blk_release_queue: - release a &struct request_queue when it is no longer needed
* @kobj: the kobj belonging to the request queue to be released
@@ -538,7 +545,7 @@ static void blk_release_queue(struct kobject *kobj)
bdi_destroy(&q->backing_dev_info);
ida_simple_remove(&blk_queue_ida, q->id);
- kmem_cache_free(blk_requestq_cachep, q);
+ call_rcu(&q->rcu_head, blk_free_queue_rcu);
}
static const struct sysfs_ops queue_sysfs_ops = {
diff --git a/block/blk.h b/block/blk.h
index 47fdfdd41520..e837b8f619b7 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -61,7 +61,7 @@ static inline void blk_clear_rq_complete(struct request *rq)
/*
* Internal elevator interface
*/
-#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
+#define ELV_ON_HASH(rq) hash_hashed(&(rq)->hash)
void blk_insert_flush(struct request *rq);
void blk_abort_flushes(struct request_queue *q);
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
diff --git a/block/elevator.c b/block/elevator.c
index d0acb31cc083..a0ffdd943c98 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -46,11 +46,6 @@ static LIST_HEAD(elv_list);
/*
* Merge hash stuff.
*/
-static const int elv_hash_shift = 6;
-#define ELV_HASH_BLOCK(sec) ((sec) >> 3)
-#define ELV_HASH_FN(sec) \
- (hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift))
-#define ELV_HASH_ENTRIES (1 << elv_hash_shift)
#define rq_hash_key(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq))
/*
@@ -158,7 +153,6 @@ static struct elevator_queue *elevator_alloc(struct request_queue *q,
struct elevator_type *e)
{
struct elevator_queue *eq;
- int i;
eq = kmalloc_node(sizeof(*eq), GFP_KERNEL | __GFP_ZERO, q->node);
if (unlikely(!eq))
@@ -167,14 +161,7 @@ static struct elevator_queue *elevator_alloc(struct request_queue *q,
eq->type = e;
kobject_init(&eq->kobj, &elv_ktype);
mutex_init(&eq->sysfs_lock);
-
- eq->hash = kmalloc_node(sizeof(struct hlist_head) * ELV_HASH_ENTRIES,
- GFP_KERNEL, q->node);
- if (!eq->hash)
- goto err;
-
- for (i = 0; i < ELV_HASH_ENTRIES; i++)
- INIT_HLIST_HEAD(&eq->hash[i]);
+ hash_init(eq->hash);
return eq;
err:
@@ -189,7 +176,6 @@ static void elevator_release(struct kobject *kobj)
e = container_of(kobj, struct elevator_queue, kobj);
elevator_put(e->type);
- kfree(e->hash);
kfree(e);
}
@@ -261,7 +247,7 @@ EXPORT_SYMBOL(elevator_exit);
static inline void __elv_rqhash_del(struct request *rq)
{
- hlist_del_init(&rq->hash);
+ hash_del(&rq->hash);
}
static void elv_rqhash_del(struct request_queue *q, struct request *rq)
@@ -275,7 +261,7 @@ static void elv_rqhash_add(struct request_queue *q, struct request *rq)
struct elevator_queue *e = q->elevator;
BUG_ON(ELV_ON_HASH(rq));
- hlist_add_head(&rq->hash, &e->hash[ELV_HASH_FN(rq_hash_key(rq))]);
+ hash_add(e->hash, &rq->hash, rq_hash_key(rq));
}
static void elv_rqhash_reposition(struct request_queue *q, struct request *rq)
@@ -287,11 +273,10 @@ static void elv_rqhash_reposition(struct request_queue *q, struct request *rq)
static struct request *elv_rqhash_find(struct request_queue *q, sector_t offset)
{
struct elevator_queue *e = q->elevator;
- struct hlist_head *hash_list = &e->hash[ELV_HASH_FN(offset)];
struct hlist_node *next;
struct request *rq;
- hlist_for_each_entry_safe(rq, next, hash_list, hash) {
+ hash_for_each_possible_safe(e->hash, rq, next, hash, offset) {
BUG_ON(!ELV_ON_HASH(rq));
if (unlikely(!rq_mergeable(rq))) {