Re: [PATCH 1/8 v2] cfq-iosched: Introduce cfq_entity for CFQ queue
From: Gui Jianfeng
Date: Mon Dec 13 2010 - 20:30:40 EST
Vivek Goyal wrote:
> On Mon, Dec 13, 2010 at 09:44:24AM +0800, Gui Jianfeng wrote:
>> Introduce cfq_entity for CFQ queue
>>
>> Signed-off-by: Gui Jianfeng <guijianfeng@xxxxxxxxxxxxxx>
>> ---
>> block/cfq-iosched.c | 125 +++++++++++++++++++++++++++++++++-----------------
>> 1 files changed, 82 insertions(+), 43 deletions(-)
>>
>> diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
>> index 5d0349d..9b07a24 100644
>> --- a/block/cfq-iosched.c
>> +++ b/block/cfq-iosched.c
>> @@ -91,20 +91,31 @@ struct cfq_rb_root {
>> #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, .left = NULL, \
>> .count = 0, .min_vdisktime = 0, }
>>
>> +
>> +/*
>> + * This's the CFQ queue schedule entity which is scheduled on service tree.
>> + */
>> +struct cfq_entity {
>> + /* service tree */
>> + struct cfq_rb_root *service_tree;
>> + /* service_tree member */
>> + struct rb_node rb_node;
>> + /* service_tree key, represent the position on the tree */
>> + unsigned long rb_key;
>> +};
>> +
>> /*
>> * Per process-grouping structure
>> */
>> struct cfq_queue {
>> + /* The schedule entity */
>> + struct cfq_entity cfqe;
>> /* reference count */
>> atomic_t ref;
>> /* various state flags, see below */
>> unsigned int flags;
>> /* parent cfq_data */
>> struct cfq_data *cfqd;
>> - /* service_tree member */
>> - struct rb_node rb_node;
>> - /* service_tree key */
>> - unsigned long rb_key;
>> /* prio tree member */
>> struct rb_node p_node;
>> /* prio tree root we belong to, if any */
>> @@ -143,7 +154,6 @@ struct cfq_queue {
>> u32 seek_history;
>> sector_t last_request_pos;
>>
>> - struct cfq_rb_root *service_tree;
>> struct cfq_queue *new_cfqq;
>> struct cfq_group *cfqg;
>> struct cfq_group *orig_cfqg;
>> @@ -302,6 +312,15 @@ struct cfq_data {
>> struct rcu_head rcu;
>> };
>>
>> +static inline struct cfq_queue *
>> +cfqq_of_entity(struct cfq_entity *cfqe)
>> +{
>> + if (cfqe)
>> + return container_of(cfqe, struct cfq_queue,
>> + cfqe);
>> + return NULL;
>> +}
>> +
>> static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd);
>>
>> static struct cfq_rb_root *service_tree_for(struct cfq_group *cfqg,
>> @@ -743,7 +762,7 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2,
>> /*
>> * The below is leftmost cache rbtree addon
>> */
>> -static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
>> +static struct cfq_entity *cfq_rb_first(struct cfq_rb_root *root)
>> {
>> /* Service tree is empty */
>> if (!root->count)
>> @@ -753,7 +772,7 @@ static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
>> root->left = rb_first(&root->rb);
>>
>> if (root->left)
>> - return rb_entry(root->left, struct cfq_queue, rb_node);
>> + return rb_entry(root->left, struct cfq_entity, rb_node);
>>
>> return NULL;
>> }
>> @@ -1170,21 +1189,24 @@ static inline void cfq_put_cfqg(struct cfq_group *cfqg) {}
>> static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
>> bool add_front)
>> {
>> + struct cfq_entity *cfqe;
>> struct rb_node **p, *parent;
>> - struct cfq_queue *__cfqq;
>> + struct cfq_entity *__cfqe;
>> unsigned long rb_key;
>> struct cfq_rb_root *service_tree;
>> int left;
>> int new_cfqq = 1;
>> int group_changed = 0;
>>
>> + cfqe = &cfqq->cfqe;
>> +
>> #ifdef CONFIG_CFQ_GROUP_IOSCHED
>> if (!cfqd->cfq_group_isolation
>> && cfqq_type(cfqq) == SYNC_NOIDLE_WORKLOAD
>> && cfqq->cfqg && cfqq->cfqg != &cfqd->root_group) {
>> /* Move this cfq to root group */
>> cfq_log_cfqq(cfqd, cfqq, "moving to root group");
>> - if (!RB_EMPTY_NODE(&cfqq->rb_node))
>> + if (!RB_EMPTY_NODE(&cfqe->rb_node))
>> cfq_group_service_tree_del(cfqd, cfqq->cfqg);
>> cfqq->orig_cfqg = cfqq->cfqg;
>> cfqq->cfqg = &cfqd->root_group;
>> @@ -1194,7 +1216,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
>> && cfqq_type(cfqq) == SYNC_WORKLOAD && cfqq->orig_cfqg) {
>> /* cfqq is sequential now needs to go to its original group */
>> BUG_ON(cfqq->cfqg != &cfqd->root_group);
>> - if (!RB_EMPTY_NODE(&cfqq->rb_node))
>> + if (!RB_EMPTY_NODE(&cfqe->rb_node))
>> cfq_group_service_tree_del(cfqd, cfqq->cfqg);
>> cfq_put_cfqg(cfqq->cfqg);
>> cfqq->cfqg = cfqq->orig_cfqg;
>> @@ -1209,9 +1231,11 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
>> if (cfq_class_idle(cfqq)) {
>> rb_key = CFQ_IDLE_DELAY;
>> parent = rb_last(&service_tree->rb);
>> - if (parent && parent != &cfqq->rb_node) {
>> - __cfqq = rb_entry(parent, struct cfq_queue, rb_node);
>> - rb_key += __cfqq->rb_key;
>> + if (parent && parent != &cfqe->rb_node) {
>> + __cfqe = rb_entry(parent,
>> + struct cfq_entity,
>> + rb_node);
>
> Above can fit into a single line or at max two lines?
I replaced io_sched_entity into cfq_entity automatically, but forgot to
consider to line character number. :(
Will change all.
Thanks,
Gui
>
>> + rb_key += __cfqe->rb_key;
>> } else
>> rb_key += jiffies;
>> } else if (!add_front) {
>> @@ -1226,37 +1250,39 @@ 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);
>> - rb_key += __cfqq ? __cfqq->rb_key : jiffies;
>> + __cfqe = cfq_rb_first(service_tree);
>> + rb_key += __cfqe ? __cfqe->rb_key : jiffies;
>> }
>>
>> - if (!RB_EMPTY_NODE(&cfqq->rb_node)) {
>> + if (!RB_EMPTY_NODE(&cfqe->rb_node)) {
>> new_cfqq = 0;
>> /*
>> * same position, nothing more to do
>> */
>> - if (rb_key == cfqq->rb_key &&
>> - cfqq->service_tree == service_tree)
>> + if (rb_key == cfqe->rb_key &&
>> + cfqe->service_tree == service_tree)
>> return;
>>
>> - cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree);
>> - cfqq->service_tree = NULL;
>> + cfq_rb_erase(&cfqe->rb_node,
>> + cfqe->service_tree);
>
> Above can fit on single line?
>
>> + cfqe->service_tree = NULL;
>> }
>>
>> left = 1;
>> parent = NULL;
>> - cfqq->service_tree = service_tree;
>> + cfqe->service_tree = service_tree;
>> p = &service_tree->rb.rb_node;
>> while (*p) {
>> struct rb_node **n;
>>
>> parent = *p;
>> - __cfqq = rb_entry(parent, struct cfq_queue, rb_node);
>> + __cfqe = rb_entry(parent, struct cfq_entity,
>> + rb_node);
>
> Single line.
>
>>
>> /*
>> * sort by key, that represents service time.
>> */
>> - if (time_before(rb_key, __cfqq->rb_key))
>> + if (time_before(rb_key, __cfqe->rb_key))
>> n = &(*p)->rb_left;
>> else {
>> n = &(*p)->rb_right;
>> @@ -1267,11 +1293,11 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
>> }
>>
>> if (left)
>> - service_tree->left = &cfqq->rb_node;
>> + service_tree->left = &cfqe->rb_node;
>>
>> - cfqq->rb_key = rb_key;
>> - rb_link_node(&cfqq->rb_node, parent, p);
>> - rb_insert_color(&cfqq->rb_node, &service_tree->rb);
>> + cfqe->rb_key = rb_key;
>> + rb_link_node(&cfqe->rb_node, parent, p);
>> + rb_insert_color(&cfqe->rb_node, &service_tree->rb);
>> service_tree->count++;
>> if ((add_front || !new_cfqq) && !group_changed)
>> return;
>> @@ -1373,13 +1399,17 @@ static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
>> */
>> static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
>> {
>> + struct cfq_entity *cfqe;
>> cfq_log_cfqq(cfqd, cfqq, "del_from_rr");
>> BUG_ON(!cfq_cfqq_on_rr(cfqq));
>> cfq_clear_cfqq_on_rr(cfqq);
>>
>> - if (!RB_EMPTY_NODE(&cfqq->rb_node)) {
>> - cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree);
>> - cfqq->service_tree = NULL;
>> + cfqe = &cfqq->cfqe;
>> +
>> + if (!RB_EMPTY_NODE(&cfqe->rb_node)) {
>> + cfq_rb_erase(&cfqe->rb_node,
>> + cfqe->service_tree);
>
> Single line above.
>
>
>> + cfqe->service_tree = NULL;
>> }
>> if (cfqq->p_root) {
>> rb_erase(&cfqq->p_node, cfqq->p_root);
>> @@ -1707,13 +1737,13 @@ static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
>> return NULL;
>> if (RB_EMPTY_ROOT(&service_tree->rb))
>> return NULL;
>> - return cfq_rb_first(service_tree);
>> + return cfqq_of_entity(cfq_rb_first(service_tree));
>> }
>>
>> static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd)
>> {
>> struct cfq_group *cfqg;
>> - struct cfq_queue *cfqq;
>> + struct cfq_entity *cfqe;
>> int i, j;
>> struct cfq_rb_root *st;
>>
>> @@ -1724,9 +1754,11 @@ static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd)
>> if (!cfqg)
>> return NULL;
>>
>> - for_each_cfqg_st(cfqg, i, j, st)
>> - if ((cfqq = cfq_rb_first(st)) != NULL)
>> - return cfqq;
>> + for_each_cfqg_st(cfqg, i, j, st) {
>> + cfqe = cfq_rb_first(st);
>> + if (cfqe != NULL)
>> + return cfqq_of_entity(cfqe);
>> + }
>> return NULL;
>> }
>>
>> @@ -1863,9 +1895,12 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd,
>>
>> static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
>> {
>> + struct cfq_entity *cfqe;
>> enum wl_prio_t prio = cfqq_prio(cfqq);
>> - struct cfq_rb_root *service_tree = cfqq->service_tree;
>> + struct cfq_rb_root *service_tree;
>>
>> + cfqe = &cfqq->cfqe;
>> + service_tree = cfqe->service_tree;
>> BUG_ON(!service_tree);
>> BUG_ON(!service_tree->count);
>>
>> @@ -2075,7 +2110,7 @@ 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)
>> {
>> - struct cfq_queue *queue;
>> + struct cfq_entity *cfqe;
>> int i;
>> bool key_valid = false;
>> unsigned long lowest_key = 0;
>> @@ -2083,10 +2118,11 @@ 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));
>> - if (queue &&
>> - (!key_valid || time_before(queue->rb_key, lowest_key))) {
>> - lowest_key = queue->rb_key;
>> + cfqe = cfq_rb_first(service_tree_for(cfqg, prio, i));
>> + if (cfqe &&
>> + (!key_valid ||
>> + time_before(cfqe->rb_key, lowest_key))) {
>
> Merge two lines into one above.
>
>> + lowest_key = cfqe->rb_key;
>> cur_best = i;
>> key_valid = true;
>> }
>> @@ -2834,7 +2870,10 @@ static void cfq_ioc_set_ioprio(struct io_context *ioc)
>> static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
>> pid_t pid, bool is_sync)
>> {
>> - RB_CLEAR_NODE(&cfqq->rb_node);
>> + struct cfq_entity *cfqe;
>> +
>> + cfqe = &cfqq->cfqe;
>> + RB_CLEAR_NODE(&cfqe->rb_node);
>> RB_CLEAR_NODE(&cfqq->p_node);
>> INIT_LIST_HEAD(&cfqq->fifo);
>>
>> @@ -3243,7 +3282,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
>> /* Allow preemption only if we are idling on sync-noidle tree */
>> if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD &&
>> cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD &&
>> - new_cfqq->service_tree->count == 2 &&
>> + new_cfqq->cfqe.service_tree->count == 2 &&
>> RB_EMPTY_ROOT(&cfqq->sort_list))
>> return true;
>>
>
> Apart from above minor nits, this patch looks good to me.
>
> Acked-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
>
> Vivek
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
--
Regards
Gui Jianfeng
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/