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>
This commit is contained in:
Vivek Goyal 2009-12-03 12:59:39 -05:00 committed by Jens Axboe
parent cdb16e8f73
commit 615f0259e6

View file

@ -140,9 +140,9 @@ struct cfq_queue {
* IDLE is handled separately, so it has negative index * IDLE is handled separately, so it has negative index
*/ */
enum wl_prio_t { enum wl_prio_t {
IDLE_WORKLOAD = -1,
BE_WORKLOAD = 0, 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...) \ #define cfq_log(cfqd, fmt, args...) \
blk_add_trace_msg((cfqd)->queue, "cfq " 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) static inline enum wl_prio_t cfqq_prio(struct cfq_queue *cfqq)
{ {
if (cfq_class_idle(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) static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
{ {
/* Service tree is empty */
if (!root->count)
return NULL;
if (!root->left) if (!root->left)
root->left = rb_first(&root->rb); root->left = rb_first(&root->rb);
@ -1587,18 +1602,14 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd)
int dispatched = 0; int dispatched = 0;
int i, j; int i, j;
struct cfq_group *cfqg = &cfqd->root_group; struct cfq_group *cfqg = &cfqd->root_group;
struct cfq_rb_root *st;
for (i = 0; i < 2; ++i) for_each_cfqg_st(cfqg, i, j, st) {
for (j = 0; j < 3; ++j) while ((cfqq = cfq_rb_first(st)) != NULL)
while ((cfqq = cfq_rb_first(&cfqg->service_trees[i][j])) dispatched += __cfq_forced_dispatch_cfqq(cfqq);
!= NULL) }
dispatched += __cfq_forced_dispatch_cfqq(cfqq);
while ((cfqq = cfq_rb_first(&cfqg->service_tree_idle)) != NULL)
dispatched += __cfq_forced_dispatch_cfqq(cfqq);
cfq_slice_expired(cfqd, 0); cfq_slice_expired(cfqd, 0);
BUG_ON(cfqd->busy_queues); BUG_ON(cfqd->busy_queues);
cfq_log(cfqd, "forced_dispatch=%d", dispatched); cfq_log(cfqd, "forced_dispatch=%d", dispatched);
@ -2969,6 +2980,7 @@ static void *cfq_init_queue(struct request_queue *q)
struct cfq_data *cfqd; struct cfq_data *cfqd;
int i, j; int i, j;
struct cfq_group *cfqg; struct cfq_group *cfqg;
struct cfq_rb_root *st;
cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node);
if (!cfqd) if (!cfqd)
@ -2976,11 +2988,8 @@ static void *cfq_init_queue(struct request_queue *q)
/* Init root group */ /* Init root group */
cfqg = &cfqd->root_group; cfqg = &cfqd->root_group;
for_each_cfqg_st(cfqg, i, j, st)
for (i = 0; i < 2; ++i) *st = CFQ_RB_ROOT;
for (j = 0; j < 3; ++j)
cfqg->service_trees[i][j] = CFQ_RB_ROOT;
cfqg->service_tree_idle = CFQ_RB_ROOT;
/* /*
* Not strictly needed (since RB_ROOT just clears the node and we * Not strictly needed (since RB_ROOT just clears the node and we