From: Davidlohr Bueso <dave@xxxxxxxxxxxx> Subject: block/cfq: replace cfq_rb_root leftmost caching ... with the generic rbtree flavor instead. No changes in semantics whatsoever. Link: http://lkml.kernel.org/r/20170719014603.19029-11-dave@xxxxxxxxxxxx Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- block/cfq-iosched.c | 70 ++++++++++++------------------------------ 1 file changed, 20 insertions(+), 50 deletions(-) diff -puN block/cfq-iosched.c~block-cfq-replace-cfq_rb_root-leftmost-caching block/cfq-iosched.c --- a/block/cfq-iosched.c~block-cfq-replace-cfq_rb_root-leftmost-caching +++ a/block/cfq-iosched.c @@ -93,13 +93,12 @@ struct cfq_ttime { * move this into the elevator for the rq sorting as well. */ struct cfq_rb_root { - struct rb_root rb; - struct rb_node *left; + struct rb_root_cached rb; unsigned count; u64 min_vdisktime; struct cfq_ttime ttime; }; -#define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, \ +#define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT_CACHED, \ .ttime = {.last_end_request = ktime_get_ns(),},} /* @@ -981,10 +980,9 @@ static inline u64 max_vdisktime(u64 min_ static void update_min_vdisktime(struct cfq_rb_root *st) { - struct cfq_group *cfqg; + if (!RB_EMPTY_ROOT(&st->rb.rb_root)) { + struct cfq_group *cfqg = rb_entry_cfqg(st->rb.rb_leftmost); - if (st->left) { - cfqg = rb_entry_cfqg(st->left); st->min_vdisktime = max_vdisktime(st->min_vdisktime, cfqg->vdisktime); } @@ -1166,46 +1164,25 @@ cfq_choose_req(struct cfq_data *cfqd, st } } -/* - * The below is leftmost cache rbtree addon - */ static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) { /* Service tree is empty */ if (!root->count) return NULL; - if (!root->left) - root->left = rb_first(&root->rb); - - if (root->left) - return rb_entry(root->left, struct cfq_queue, rb_node); - - return NULL; + return rb_entry(rb_first_cached(&root->rb), struct cfq_queue, rb_node); } 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; + return rb_entry_cfqg(rb_first_cached(&root->rb)); } -static void rb_erase_init(struct rb_node *n, struct rb_root *root) +static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) { - rb_erase(n, root); + rb_erase_cached(n, &root->rb); RB_CLEAR_NODE(n); -} -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; } @@ -1255,11 +1232,11 @@ cfqg_key(struct cfq_rb_root *st, struct 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 **node = &st->rb.rb_root.rb_node; struct rb_node *parent = NULL; struct cfq_group *__cfqg; s64 key = cfqg_key(st, cfqg); - int left = 1; + bool leftmost = true; while (*node != NULL) { parent = *node; @@ -1269,15 +1246,12 @@ __cfq_group_service_tree_add(struct cfq_ node = &parent->rb_left; else { node = &parent->rb_right; - left = 0; + leftmost = false; } } - if (left) - st->left = &cfqg->rb_node; - rb_link_node(&cfqg->rb_node, parent, node); - rb_insert_color(&cfqg->rb_node, &st->rb); + rb_insert_color_cached(&cfqg->rb_node, &st->rb, leftmost); } /* @@ -1378,7 +1352,7 @@ cfq_group_notify_queue_add(struct cfq_da * so that groups get lesser vtime based on their weights, so that * if group does not loose all if it was not continuously backlogged. */ - n = rb_last(&st->rb); + n = rb_last(&st->rb.rb_root); if (n) { __cfqg = rb_entry_cfqg(n); cfqg->vdisktime = __cfqg->vdisktime + @@ -2220,14 +2194,14 @@ static void cfq_service_tree_add(struct struct cfq_queue *__cfqq; u64 rb_key; struct cfq_rb_root *st; - int left; + bool leftmost = true; int new_cfqq = 1; u64 now = ktime_get_ns(); st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq)); if (cfq_class_idle(cfqq)) { rb_key = CFQ_IDLE_DELAY; - parent = rb_last(&st->rb); + parent = rb_last(&st->rb.rb_root); if (parent && parent != &cfqq->rb_node) { __cfqq = rb_entry(parent, struct cfq_queue, rb_node); rb_key += __cfqq->rb_key; @@ -2261,10 +2235,9 @@ static void cfq_service_tree_add(struct cfqq->service_tree = NULL; } - left = 1; parent = NULL; cfqq->service_tree = st; - p = &st->rb.rb_node; + p = &st->rb.rb_root.rb_node; while (*p) { parent = *p; __cfqq = rb_entry(parent, struct cfq_queue, rb_node); @@ -2276,16 +2249,13 @@ static void cfq_service_tree_add(struct p = &parent->rb_left; else { p = &parent->rb_right; - left = 0; + leftmost = false; } } - if (left) - st->left = &cfqq->rb_node; - cfqq->rb_key = rb_key; rb_link_node(&cfqq->rb_node, parent, p); - rb_insert_color(&cfqq->rb_node, &st->rb); + rb_insert_color_cached(&cfqq->rb_node, &st->rb, leftmost); st->count++; if (add_front || !new_cfqq) return; @@ -2732,7 +2702,7 @@ static struct cfq_queue *cfq_get_next_qu /* There is nothing to dispatch */ if (!st) return NULL; - if (RB_EMPTY_ROOT(&st->rb)) + if (RB_EMPTY_ROOT(&st->rb.rb_root)) return NULL; return cfq_rb_first(st); } @@ -3219,7 +3189,7 @@ static struct cfq_group *cfq_get_next_cf struct cfq_rb_root *st = &cfqd->grp_service_tree; struct cfq_group *cfqg; - if (RB_EMPTY_ROOT(&st->rb)) + if (RB_EMPTY_ROOT(&st->rb.rb_root)) return NULL; cfqg = cfq_rb_first_group(st); update_min_vdisktime(st); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
