lkml.org 
[lkml]   [2009]   [Nov]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 03/21] blkio: Implement macro to traverse each idle tree in group
Date
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>
---
block/cfq-iosched.c | 35 +++++++++++++++++++++--------------
1 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 3baa3f4..c73ff44 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -303,6 +303,15 @@ 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 < 3; i++) \
+ for (j = 0, st = i < 2 ? &cfqg->service_trees[i][j] : \
+ &cfqg->service_tree_idle; \
+ (i < 2 && j < 3) || (i == 2 && j < 1); \
+ j++, st = i < 2 ? &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 +574,10 @@ 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);

@@ -1592,18 +1605,14 @@ 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);
@@ -2974,6 +2983,7 @@ 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)
@@ -2981,11 +2991,8 @@ 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
--
1.6.2.5


\
 
 \ /
  Last update: 2009-11-30 04:07    [W:0.226 / U:0.196 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site