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Message-ID: <4CBFA712.8000007@cn.fujitsu.com>
Date: Thu, 21 Oct 2010 10:36:02 +0800
From: Gui Jianfeng <guijianfeng@...fujitsu.com>
To: Vivek Goyal <vgoyal@...hat.com>, Jens Axboe <axboe@...nel.dk>
CC: Nauman Rafique <nauman@...gle.com>,
Chad Talbott <ctalbott@...gle.com>,
Divyesh Shah <dpshah@...gle.com>,
linux kernel mailing list <linux-kernel@...r.kernel.org>,
Gui Jianfeng <guijianfeng@...fujitsu.com>
Subject: [PATCH 2/4] blkio-cgroup: Add a new interface use_hierarchy
This patch just adds a new interface use_hierarchy without enabling any
functinality. Currently, "use_hierarchy" only occurs in root cgroup.
Latter patch will make use of this interface to switch between hierarchical
mode and flat mode for cfq group scheduling.
Signed-off-by: Gui Jianfeng <guijianfeng@...fujitsu.com>
---
block/blk-cgroup.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++--
block/blk-cgroup.h | 5 +++-
block/cfq-iosched.c | 26 +++++++++++++++++-
3 files changed, 100 insertions(+), 5 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 455768a..5ff5b60 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -25,7 +25,10 @@
static DEFINE_SPINLOCK(blkio_list_lock);
static LIST_HEAD(blkio_list);
-struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
+struct blkio_cgroup blkio_root_cgroup = {
+ .weight = 2*BLKIO_WEIGHT_DEFAULT,
+ .use_hierarchy = 1,
+ };
EXPORT_SYMBOL_GPL(blkio_root_cgroup);
static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *,
@@ -433,6 +436,8 @@ void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
struct blkio_group *blkg, void *key, dev_t dev,
enum blkio_policy_id plid)
{
+ struct hlist_node *n;
+
unsigned long flags;
spin_lock_irqsave(&blkcg->lock, flags);
@@ -1385,10 +1390,73 @@ struct cftype blkio_files[] = {
#endif
};
+static u64 blkiocg_use_hierarchy_read(struct cgroup *cgroup,
+ struct cftype *cftype)
+{
+ struct blkio_cgroup *blkcg;
+
+ blkcg = cgroup_to_blkio_cgroup(cgroup);
+ return (u64)blkcg->use_hierarchy;
+}
+
+static int
+blkiocg_use_hierarchy_write(struct cgroup *cgroup,
+ struct cftype *cftype, u64 val)
+{
+ struct blkio_cgroup *blkcg;
+ struct blkio_group *blkg;
+ struct hlist_node *n;
+ struct blkio_policy_type *blkiop;
+
+ blkcg = cgroup_to_blkio_cgroup(cgroup);
+
+ if (val > 1 || !list_empty(&cgroup->children))
+ return -EINVAL;
+
+ if (blkcg->use_hierarchy == val)
+ return 0;
+
+ spin_lock(&blkio_list_lock);
+ blkcg->use_hierarchy = val;
+
+ hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
+ /*
+ * If this policy does not own the blkg, do not change
+ * cfq group scheduling mode.
+ */
+ if (blkiop->plid != blkg->plid)
+ continue;
+
+ list_for_each_entry(blkiop, &blkio_list, list) {
+ if (blkiop->ops.blkio_update_use_hierarchy_fn)
+ blkiop->ops.blkio_update_use_hierarchy_fn(blkg,
+ val);
+ }
+ }
+ spin_unlock(&blkio_list_lock);
+ return 0;
+}
+
+static struct cftype blkio_use_hierarchy = {
+ .name = "use_hierarchy",
+ .read_u64 = blkiocg_use_hierarchy_read,
+ .write_u64 = blkiocg_use_hierarchy_write,
+};
+
static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup)
{
- return cgroup_add_files(cgroup, subsys, blkio_files,
- ARRAY_SIZE(blkio_files));
+ int ret;
+
+ ret = cgroup_add_files(cgroup, subsys, blkio_files,
+ ARRAY_SIZE(blkio_files));
+ if (ret)
+ return ret;
+
+ /* use_hierarchy is in root cgroup only. */
+ if (!cgroup->parent)
+ ret = cgroup_add_file(cgroup, subsys, &blkio_use_hierarchy);
+
+ return ret;
}
static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index ea4861b..c8caf4e 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -105,6 +105,7 @@ enum blkcg_file_name_throtl {
struct blkio_cgroup {
struct cgroup_subsys_state css;
unsigned int weight;
+ bool use_hierarchy;
spinlock_t lock;
struct hlist_head blkg_list;
struct list_head policy_list; /* list of blkio_policy_node */
@@ -200,7 +201,8 @@ typedef void (blkio_update_group_read_iops_fn) (void *key,
struct blkio_group *blkg, unsigned int read_iops);
typedef void (blkio_update_group_write_iops_fn) (void *key,
struct blkio_group *blkg, unsigned int write_iops);
-
+typedef void (blkio_update_use_hierarchy_fn) (struct blkio_group *blkg,
+ bool val);
struct blkio_policy_ops {
blkio_unlink_group_fn *blkio_unlink_group_fn;
blkio_update_group_weight_fn *blkio_update_group_weight_fn;
@@ -208,6 +210,7 @@ struct blkio_policy_ops {
blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
+ blkio_update_use_hierarchy_fn *blkio_update_use_hierarchy_fn;
};
struct blkio_policy_type {
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 5c3953d..f781e4d 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -200,6 +200,9 @@ struct cfq_group {
/* Service tree for cfq_groups and cfqqs set*/
struct cfq_rb_root grp_service_tree;
+ /* parent cfq_data */
+ struct cfq_data *cfqd;
+
/* number of cfqq currently on this group */
int nr_cfqq;
@@ -234,6 +237,9 @@ struct cfq_data {
struct request_queue *queue;
struct cfq_group root_group;
+ /* cfq group schedule in flat or hierarchy manner. */
+ bool use_hierarchy;
+
/*
* The priority currently being served
*/
@@ -854,7 +860,7 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
* just an approximation, should be ok.
*/
return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) -
- cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio));
+ cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio));
}
static inline s64
@@ -1119,6 +1125,15 @@ static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg)
cfq_put_cfqg(cfqg);
}
+void
+cfq_update_blkio_use_hierarchy(struct blkio_group *blkg, bool val)
+{
+ struct cfq_group *cfqg;
+
+ cfqg = cfqg_of_blkg(blkg);
+ cfqg->cfqd->use_hierarchy = val;
+}
+
static void init_group_queue_entity(struct blkio_cgroup *blkcg,
struct cfq_group *cfqg)
{
@@ -1169,6 +1184,9 @@ static void init_cfqg(struct cfq_data *cfqd, struct blkio_cgroup *blkcg,
*/
atomic_set(&cfqg->ref, 1);
+ /* Setup cfq data for cfq group */
+ cfqg->cfqd = cfqd;
+
/* Add group onto cgroup list */
sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
@@ -4073,6 +4091,7 @@ static void *cfq_init_queue(struct request_queue *q)
/* Init root group */
cfqg = &cfqd->root_group;
+ cfqg->cfqd = cfqd;
cfqg->grp_service_tree = CFQ_RB_ROOT;
for_each_cfqg_st(cfqg, i, j, st)
*st = CFQ_RB_ROOT;
@@ -4142,6 +4161,10 @@ static void *cfq_init_queue(struct request_queue *q)
cfqd->cfq_latency = 1;
cfqd->cfq_group_isolation = 0;
cfqd->hw_tag = -1;
+
+ /* hierarchical scheduling for cfq group by default */
+ cfqd->use_hierarchy = 1;
+
/*
* we optimistically start assuming sync ops weren't delayed in last
* second, in order to have larger depth for async operations.
@@ -4304,6 +4327,7 @@ static struct blkio_policy_type blkio_policy_cfq = {
.ops = {
.blkio_unlink_group_fn = cfq_unlink_blkio_group,
.blkio_update_group_weight_fn = cfq_update_blkio_group_weight,
+ .blkio_update_use_hierarchy_fn = cfq_update_blkio_use_hierarchy,
},
.plid = BLKIO_POLICY_PROP,
};
-- 1.6.5.2
--
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