Commit 25fb5169 authored by Vivek Goyal's avatar Vivek Goyal Committed by Jens Axboe

blkio: Dynamic cfq group creation based on cgroup tasks belongs to

o Determine the cgroup IO submitting task belongs to and create the cfq
  group if it does not exist already.

o Also link cfqq and associated cfq group.

o Currently all async IO is mapped to root group.
Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent dae739eb
......@@ -189,6 +189,10 @@ struct cfq_group {
unsigned long saved_workload_slice;
enum wl_type_t saved_workload;
enum wl_prio_t saved_serving_prio;
struct blkio_group blkg;
#ifdef CONFIG_CFQ_GROUP_IOSCHED
struct hlist_node cfqd_node;
#endif
};
/*
......@@ -274,8 +278,13 @@ struct cfq_data {
struct cfq_queue oom_cfqq;
unsigned long last_end_sync_rq;
/* List of cfq groups being managed on this device*/
struct hlist_head cfqg_list;
};
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,
enum wl_type_t type,
......@@ -881,6 +890,89 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
cfqg->saved_workload_slice = 0;
}
#ifdef CONFIG_CFQ_GROUP_IOSCHED
static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg)
{
if (blkg)
return container_of(blkg, struct cfq_group, blkg);
return NULL;
}
static struct cfq_group *
cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
{
struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
struct cfq_group *cfqg = NULL;
void *key = cfqd;
int i, j;
struct cfq_rb_root *st;
/* Do we need to take this reference */
if (!css_tryget(&blkcg->css))
return NULL;;
cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
if (cfqg || !create)
goto done;
cfqg = kzalloc_node(sizeof(*cfqg), GFP_ATOMIC, cfqd->queue->node);
if (!cfqg)
goto done;
cfqg->weight = blkcg->weight;
for_each_cfqg_st(cfqg, i, j, st)
*st = CFQ_RB_ROOT;
RB_CLEAR_NODE(&cfqg->rb_node);
/* Add group onto cgroup list */
blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd);
/* Add group on cfqd list */
hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
done:
css_put(&blkcg->css);
return cfqg;
}
/*
* Search for the cfq group current task belongs to. If create = 1, then also
* create the cfq group if it does not exist. request_queue lock must be held.
*/
static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
{
struct cgroup *cgroup;
struct cfq_group *cfqg = NULL;
rcu_read_lock();
cgroup = task_cgroup(current, blkio_subsys_id);
cfqg = cfq_find_alloc_cfqg(cfqd, cgroup, create);
if (!cfqg && create)
cfqg = &cfqd->root_group;
rcu_read_unlock();
return cfqg;
}
static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg)
{
/* Currently, all async queues are mapped to root group */
if (!cfq_cfqq_sync(cfqq))
cfqg = &cfqq->cfqd->root_group;
cfqq->cfqg = cfqg;
}
#else /* GROUP_IOSCHED */
static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
{
return &cfqd->root_group;
}
static inline void
cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) {
cfqq->cfqg = cfqg;
}
#endif /* GROUP_IOSCHED */
/*
* The cfqd->service_trees holds all pending cfq_queue's that have
* requests waiting to be processed. It is sorted in the order that
......@@ -1372,7 +1464,7 @@ static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd)
{
struct cfq_group *cfqg = &cfqd->root_group;
struct cfq_group *cfqg;
struct cfq_queue *cfqq;
int i, j;
struct cfq_rb_root *st;
......@@ -1380,6 +1472,10 @@ static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd)
if (!cfqd->rq_queued)
return NULL;
cfqg = cfq_get_next_cfqg(cfqd);
if (!cfqg)
return NULL;
for_each_cfqg_st(cfqg, i, j, st)
if ((cfqq = cfq_rb_first(st)) != NULL)
return cfqq;
......@@ -2390,16 +2486,6 @@ static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
cfqq->pid = pid;
}
static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg)
{
cfqq->cfqg = cfqg;
}
static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
{
return &cfqd->root_group;
}
static struct cfq_queue *
cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync,
struct io_context *ioc, gfp_t gfp_mask)
......@@ -3314,6 +3400,9 @@ static void *cfq_init_queue(struct request_queue *q)
/* Give preference to root group over other groups */
cfqg->weight = 2*BLKIO_WEIGHT_DEFAULT;
#ifdef CONFIG_CFQ_GROUP_IOSCHED
blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, (void *)cfqd);
#endif
/*
* Not strictly needed (since RB_ROOT just clears the node and we
* zeroed cfqd on alloc), but better be safe in case someone decides
......
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