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blkio: Implement macro to traverse each service tree in group

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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>
This commit is contained in:
Vivek Goyal 2009-12-03 12:59:39 -05:00 committed by Jens Axboe
parent cdb16e8f73
commit 615f0259e6
1 changed files with 25 additions and 16 deletions
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41
block/cfq-iosched.c
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@ -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