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| author |   Vivek Goyal <vgoyal@redhat.com> | 2009-12-03 12:59:39 -0500 |
|---|---|---|
| committer |   Jens Axboe <jens.axboe@oracle.com> | 2009-12-03 19:28:51 +0100 |
| commit | 615f0259e6940293359a189f4881bb28c2fea40b (patch) | |
| tree | 36ae080bc809a8d998801c0bcfc0d63b7b892745 /block | |
| parent | blkio: Introduce the notion of cfq groups (diff) | |
| download | linux-dev-615f0259e6940293359a189f4881bb28c2fea40b.tar.xz linux-dev-615f0259e6940293359a189f4881bb28c2fea40b.zip | |
blkio: Implement macro to traverse each service tree in group
o Implement a macro to traverse each service tree in the group. This avoids
usage of double for loop and special condition for idle tree 4 times.
o Macro is little twisted because of special handling of idle class service
tree.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/cfq-iosched.c | 41 |
1 files changed, 25 insertions, 16 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index a4d17265411e..fab2be0fa215 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -140,9 +140,9 @@ struct cfq_queue { * IDLE is handled separately, so it has negative index */ enum wl_prio_t { - IDLE_WORKLOAD = -1, BE_WORKLOAD = 0, - RT_WORKLOAD = 1 + RT_WORKLOAD = 1, + IDLE_WORKLOAD = 2, }; /* @@ -303,6 +303,17 @@ CFQ_CFQQ_FNS(deep); #define cfq_log(cfqd, fmt, args...) \ blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) +/* Traverses through cfq group service trees */ +#define for_each_cfqg_st(cfqg, i, j, st) \ + for (i = 0; i <= IDLE_WORKLOAD; i++) \ + for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\ + : &cfqg->service_tree_idle; \ + (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \ + (i == IDLE_WORKLOAD && j == 0); \ + j++, st = i < IDLE_WORKLOAD ? \ + &cfqg->service_trees[i][j]: NULL) \ + + static inline enum wl_prio_t cfqq_prio(struct cfq_queue *cfqq) { if (cfq_class_idle(cfqq)) @@ -565,6 +576,10 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, */ 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); @@ -1587,18 +1602,14 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd) int dispatched = 0; int i, j; struct cfq_group *cfqg = &cfqd->root_group; + struct cfq_rb_root *st; - for (i = 0; i < 2; ++i) - for (j = 0; j < 3; ++j) - while ((cfqq = cfq_rb_first(&cfqg->service_trees[i][j])) - != NULL) - dispatched += __cfq_forced_dispatch_cfqq(cfqq); - - while ((cfqq = cfq_rb_first(&cfqg->service_tree_idle)) != NULL) - dispatched += __cfq_forced_dispatch_cfqq(cfqq); + for_each_cfqg_st(cfqg, i, j, st) { + while ((cfqq = cfq_rb_first(st)) != NULL) + dispatched += __cfq_forced_dispatch_cfqq(cfqq); + } cfq_slice_expired(cfqd, 0); - BUG_ON(cfqd->busy_queues); cfq_log(cfqd, "forced_dispatch=%d", dispatched); @@ -2969,6 +2980,7 @@ static void *cfq_init_queue(struct request_queue *q) struct cfq_data *cfqd; int i, j; struct cfq_group *cfqg; + struct cfq_rb_root *st; cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); if (!cfqd) @@ -2976,11 +2988,8 @@ static void *cfq_init_queue(struct request_queue *q) /* Init root group */ cfqg = &cfqd->root_group; - - for (i = 0; i < 2; ++i) - for (j = 0; j < 3; ++j) - cfqg->service_trees[i][j] = CFQ_RB_ROOT; - cfqg->service_tree_idle = CFQ_RB_ROOT; + for_each_cfqg_st(cfqg, i, j, st) + *st = CFQ_RB_ROOT; /* * Not strictly needed (since RB_ROOT just clears the node and we |