forked from Minki/linux
blkio: Introduce the root service tree for cfq groups
o So far we just had one cfq_group in cfq_data. To create space for more than one cfq_group, we need to have a service tree of groups where all the groups can be queued if they have active cfq queues backlogged in these. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Vivek Goyal
Jens Axboe
parent
f04a642463
commit
1fa8f6d68b
@ -66,6 +66,7 @@ static DEFINE_SPINLOCK(ioc_gone_lock);
|
||||
#define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT)
|
||||
|
||||
#define sample_valid(samples) ((samples) > 80)
|
||||
#define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node)
|
||||
|
||||
/*
|
||||
* Most of our rbtree usage is for sorting with min extraction, so
|
||||
@ -77,8 +78,9 @@ struct cfq_rb_root {
|
||||
struct rb_root rb;
|
||||
struct rb_node *left;
|
||||
unsigned count;
|
||||
u64 min_vdisktime;
|
||||
};
|
||||
#define CFQ_RB_ROOT (struct cfq_rb_root) { RB_ROOT, NULL, 0, }
|
||||
#define CFQ_RB_ROOT (struct cfq_rb_root) { RB_ROOT, NULL, 0, 0, }
|
||||
|
||||
/*
|
||||
* Per process-grouping structure
|
||||
@ -156,6 +158,16 @@ enum wl_type_t {
|
||||
|
||||
/* This is per cgroup per device grouping structure */
|
||||
struct cfq_group {
|
||||
/* group service_tree member */
|
||||
struct rb_node rb_node;
|
||||
|
||||
/* group service_tree key */
|
||||
u64 vdisktime;
|
||||
bool on_st;
|
||||
|
||||
/* number of cfqq currently on this group */
|
||||
int nr_cfqq;
|
||||
|
||||
/*
|
||||
* rr lists of queues with requests, onle rr for each priority class.
|
||||
* Counts are embedded in the cfq_rb_root
|
||||
@ -169,6 +181,8 @@ struct cfq_group {
|
||||
*/
|
||||
struct cfq_data {
|
||||
struct request_queue *queue;
|
||||
/* Root service tree for cfq_groups */
|
||||
struct cfq_rb_root grp_service_tree;
|
||||
struct cfq_group root_group;
|
||||
|
||||
/*
|
||||
@ -251,6 +265,9 @@ static struct cfq_rb_root *service_tree_for(struct cfq_group *cfqg,
|
||||
enum wl_type_t type,
|
||||
struct cfq_data *cfqd)
|
||||
{
|
||||
if (!cfqg)
|
||||
return NULL;
|
||||
|
||||
if (prio == IDLE_WORKLOAD)
|
||||
return &cfqg->service_tree_idle;
|
||||
|
||||
@ -589,6 +606,17 @@ static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root)
|
||||
{
|
||||
if (!root->left)
|
||||
root->left = rb_first(&root->rb);
|
||||
|
||||
if (root->left)
|
||||
return rb_entry_cfqg(root->left);
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static void rb_erase_init(struct rb_node *n, struct rb_root *root)
|
||||
{
|
||||
rb_erase(n, root);
|
||||
@ -640,6 +668,83 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
|
||||
cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio));
|
||||
}
|
||||
|
||||
static inline s64
|
||||
cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg)
|
||||
{
|
||||
return cfqg->vdisktime - st->min_vdisktime;
|
||||
}
|
||||
|
||||
static void
|
||||
__cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg)
|
||||
{
|
||||
struct rb_node **node = &st->rb.rb_node;
|
||||
struct rb_node *parent = NULL;
|
||||
struct cfq_group *__cfqg;
|
||||
s64 key = cfqg_key(st, cfqg);
|
||||
int left = 1;
|
||||
|
||||
while (*node != NULL) {
|
||||
parent = *node;
|
||||
__cfqg = rb_entry_cfqg(parent);
|
||||
|
||||
if (key < cfqg_key(st, __cfqg))
|
||||
node = &parent->rb_left;
|
||||
else {
|
||||
node = &parent->rb_right;
|
||||
left = 0;
|
||||
}
|
||||
}
|
||||
|
||||
if (left)
|
||||
st->left = &cfqg->rb_node;
|
||||
|
||||
rb_link_node(&cfqg->rb_node, parent, node);
|
||||
rb_insert_color(&cfqg->rb_node, &st->rb);
|
||||
}
|
||||
|
||||
static void
|
||||
cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg)
|
||||
{
|
||||
struct cfq_rb_root *st = &cfqd->grp_service_tree;
|
||||
struct cfq_group *__cfqg;
|
||||
struct rb_node *n;
|
||||
|
||||
cfqg->nr_cfqq++;
|
||||
if (cfqg->on_st)
|
||||
return;
|
||||
|
||||
/*
|
||||
* Currently put the group at the end. Later implement something
|
||||
* so that groups get lesser vtime based on their weights, so that
|
||||
* if group does not loose all if it was not continously backlogged.
|
||||
*/
|
||||
n = rb_last(&st->rb);
|
||||
if (n) {
|
||||
__cfqg = rb_entry_cfqg(n);
|
||||
cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY;
|
||||
} else
|
||||
cfqg->vdisktime = st->min_vdisktime;
|
||||
|
||||
__cfq_group_service_tree_add(st, cfqg);
|
||||
cfqg->on_st = true;
|
||||
}
|
||||
|
||||
static void
|
||||
cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
|
||||
{
|
||||
struct cfq_rb_root *st = &cfqd->grp_service_tree;
|
||||
|
||||
BUG_ON(cfqg->nr_cfqq < 1);
|
||||
cfqg->nr_cfqq--;
|
||||
/* If there are other cfq queues under this group, don't delete it */
|
||||
if (cfqg->nr_cfqq)
|
||||
return;
|
||||
|
||||
cfqg->on_st = false;
|
||||
if (!RB_EMPTY_NODE(&cfqg->rb_node))
|
||||
cfq_rb_erase(&cfqg->rb_node, st);
|
||||
}
|
||||
|
||||
/*
|
||||
* The cfqd->service_trees holds all pending cfq_queue's that have
|
||||
* requests waiting to be processed. It is sorted in the order that
|
||||
@ -722,6 +827,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
|
||||
rb_link_node(&cfqq->rb_node, parent, p);
|
||||
rb_insert_color(&cfqq->rb_node, &service_tree->rb);
|
||||
service_tree->count++;
|
||||
cfq_group_service_tree_add(cfqd, cfqq->cfqg);
|
||||
}
|
||||
|
||||
static struct cfq_queue *
|
||||
@ -832,6 +938,7 @@ static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
|
||||
cfqq->p_root = NULL;
|
||||
}
|
||||
|
||||
cfq_group_service_tree_del(cfqd, cfqq->cfqg);
|
||||
BUG_ON(!cfqd->busy_queues);
|
||||
cfqd->busy_queues--;
|
||||
}
|
||||
@ -1108,6 +1215,9 @@ static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
|
||||
if (!cfqd->rq_queued)
|
||||
return NULL;
|
||||
|
||||
/* There is nothing to dispatch */
|
||||
if (!service_tree)
|
||||
return NULL;
|
||||
if (RB_EMPTY_ROOT(&service_tree->rb))
|
||||
return NULL;
|
||||
return cfq_rb_first(service_tree);
|
||||
@ -1477,6 +1587,12 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
|
||||
unsigned count;
|
||||
struct cfq_rb_root *st;
|
||||
|
||||
if (!cfqg) {
|
||||
cfqd->serving_prio = IDLE_WORKLOAD;
|
||||
cfqd->workload_expires = jiffies + 1;
|
||||
return;
|
||||
}
|
||||
|
||||
/* Choose next priority. RT > BE > IDLE */
|
||||
if (cfq_busy_queues_wl(RT_WORKLOAD, cfqd))
|
||||
cfqd->serving_prio = RT_WORKLOAD;
|
||||
@ -1535,10 +1651,21 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
|
||||
cfqd->noidle_tree_requires_idle = false;
|
||||
}
|
||||
|
||||
static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd)
|
||||
{
|
||||
struct cfq_rb_root *st = &cfqd->grp_service_tree;
|
||||
|
||||
if (RB_EMPTY_ROOT(&st->rb))
|
||||
return NULL;
|
||||
return cfq_rb_first_group(st);
|
||||
}
|
||||
|
||||
static void cfq_choose_cfqg(struct cfq_data *cfqd)
|
||||
{
|
||||
cfqd->serving_group = &cfqd->root_group;
|
||||
choose_service_tree(cfqd, &cfqd->root_group);
|
||||
struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd);
|
||||
|
||||
cfqd->serving_group = cfqg;
|
||||
choose_service_tree(cfqd, cfqg);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -3014,10 +3141,14 @@ static void *cfq_init_queue(struct request_queue *q)
|
||||
if (!cfqd)
|
||||
return NULL;
|
||||
|
||||
/* Init root service tree */
|
||||
cfqd->grp_service_tree = CFQ_RB_ROOT;
|
||||
|
||||
/* Init root group */
|
||||
cfqg = &cfqd->root_group;
|
||||
for_each_cfqg_st(cfqg, i, j, st)
|
||||
*st = CFQ_RB_ROOT;
|
||||
RB_CLEAR_NODE(&cfqg->rb_node);
|
||||
|
||||
/*
|
||||
* Not strictly needed (since RB_ROOT just clears the node and we
|
||||
|
||||
Loading…
Reference in New Issue
Block a user