From aa6f6a3de18131348f70951efb2c56d806033e09 Mon Sep 17 00:00:00 2001 From: Corrado Zoccolo Date: Mon, 26 Oct 2009 22:44:33 +0100 Subject: cfq-iosched: preparation to handle multiple service trees We embed a pointer to the service tree in each queue, to handle multiple service trees easily. Service trees are enriched with a counter. cfq_add_rq_rb is invoked after putting the rq in the fifo, to ensure that all fields in rq are properly initialized. Signed-off-by: Corrado Zoccolo Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) (limited to 'block/cfq-iosched.c') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 97d9465..c95c69e 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -75,8 +75,9 @@ static DEFINE_SPINLOCK(ioc_gone_lock); struct cfq_rb_root { struct rb_root rb; struct rb_node *left; + unsigned count; }; -#define CFQ_RB_ROOT (struct cfq_rb_root) { RB_ROOT, NULL, } +#define CFQ_RB_ROOT (struct cfq_rb_root) { RB_ROOT, NULL, 0, } /* * Per process-grouping structure @@ -128,6 +129,7 @@ struct cfq_queue { pid_t pid; + struct cfq_rb_root *service_tree; struct cfq_queue *new_cfqq; }; @@ -503,6 +505,7 @@ static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) if (root->left == n) root->left = NULL; rb_erase_init(n, &root->rb); + --root->count; } /* @@ -553,11 +556,12 @@ 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 = &cfqd->service_tree; int left; if (cfq_class_idle(cfqq)) { rb_key = CFQ_IDLE_DELAY; - parent = rb_last(&cfqd->service_tree.rb); + 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; @@ -575,7 +579,7 @@ 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(&cfqd->service_tree); + __cfqq = cfq_rb_first(service_tree); rb_key += __cfqq ? __cfqq->rb_key : jiffies; } @@ -586,12 +590,14 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, if (rb_key == cfqq->rb_key) return; - cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree); + cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); + cfqq->service_tree = NULL; } left = 1; parent = NULL; - p = &cfqd->service_tree.rb.rb_node; + cfqq->service_tree = service_tree; + p = &service_tree->rb.rb_node; while (*p) { struct rb_node **n; @@ -623,11 +629,12 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, } if (left) - cfqd->service_tree.left = &cfqq->rb_node; + service_tree->left = &cfqq->rb_node; cfqq->rb_key = rb_key; rb_link_node(&cfqq->rb_node, parent, p); - rb_insert_color(&cfqq->rb_node, &cfqd->service_tree.rb); + rb_insert_color(&cfqq->rb_node, &service_tree->rb); + service_tree->count++; } static struct cfq_queue * @@ -730,8 +737,10 @@ static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) 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, &cfqd->service_tree); + if (!RB_EMPTY_NODE(&cfqq->rb_node)) { + cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); + cfqq->service_tree = NULL; + } if (cfqq->p_root) { rb_erase(&cfqq->p_node, cfqq->p_root); cfqq->p_root = NULL; @@ -2292,10 +2301,9 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq) cfq_log_cfqq(cfqd, cfqq, "insert_request"); cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc); - cfq_add_rq_rb(rq); - rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]); list_add_tail(&rq->queuelist, &cfqq->fifo); + cfq_add_rq_rb(rq); cfq_rq_enqueued(cfqd, cfqq, rq); } -- cgit v1.1