[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1259549968-10369-4-git-send-email-vgoyal@redhat.com>
Date: Sun, 29 Nov 2009 21:59:10 -0500
From: Vivek Goyal <vgoyal@...hat.com>
To: linux-kernel@...r.kernel.org, jens.axboe@...cle.com
Cc: nauman@...gle.com, dpshah@...gle.com, lizf@...fujitsu.com,
ryov@...inux.co.jp, fernando@....ntt.co.jp, s-uchida@...jp.nec.com,
taka@...inux.co.jp, guijianfeng@...fujitsu.com, jmoyer@...hat.com,
righi.andrea@...il.com, m-ikeda@...jp.nec.com, vgoyal@...hat.com,
czoccolo@...il.com, Alan.Brunelle@...com
Subject: [PATCH 03/21] blkio: Implement macro to traverse each idle 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@...hat.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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists