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authorVivek Goyal <vgoyal@redhat.com>2009-12-04 10:36:42 -0500
committerJens Axboe <jens.axboe@oracle.com>2009-12-04 16:38:14 +0100
commit3e2520668970aab5a764044a298e987aafc1f63d (patch)
tree088ebf7c4576d597774c8c332bab590dc3a472d6 /block
parent9d6a986c0b276085f7944cd8ad65f4f82aff7536 (diff)
downloadvexpress-lsk-3e2520668970aab5a764044a298e987aafc1f63d.tar.gz
blkio: Implement dynamic io controlling policy registration
o One of the goals of block IO controller is that it should be able to support mulitple io control policies, some of which be operational at higher level in storage hierarchy. o To begin with, we had one io controlling policy implemented by CFQ, and I hard coded the CFQ functions called by blkio. This created issues when CFQ is compiled as module. o This patch implements a basic dynamic io controlling policy registration functionality in blkio. This is similar to elevator functionality where ioschedulers register the functions dynamically. o Now in future, when more IO controlling policies are implemented, these can dynakically register with block IO controller. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block')
-rw-r--r--block/blk-cgroup.c36
-rw-r--r--block/blk-cgroup.h24
-rw-r--r--block/cfq-iosched.c14
-rw-r--r--block/cfq-iosched.h7
4 files changed, 69 insertions, 12 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 4d4a277b290..3ad497f4eed 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -15,7 +15,9 @@
#include <linux/kdev_t.h>
#include <linux/module.h>
#include "blk-cgroup.h"
-#include "cfq-iosched.h"
+
+static DEFINE_SPINLOCK(blkio_list_lock);
+static LIST_HEAD(blkio_list);
struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
EXPORT_SYMBOL_GPL(blkio_root_cgroup);
@@ -138,6 +140,7 @@ blkiocg_weight_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;
if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX)
return -EINVAL;
@@ -145,8 +148,13 @@ blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
blkcg = cgroup_to_blkio_cgroup(cgroup);
spin_lock_irq(&blkcg->lock);
blkcg->weight = (unsigned int)val;
- hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node)
- cfq_update_blkio_group_weight(blkg, blkcg->weight);
+ hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
+ spin_lock(&blkio_list_lock);
+ list_for_each_entry(blkiop, &blkio_list, list)
+ blkiop->ops.blkio_update_group_weight_fn(blkg,
+ blkcg->weight);
+ spin_unlock(&blkio_list_lock);
+ }
spin_unlock_irq(&blkcg->lock);
return 0;
}
@@ -224,6 +232,7 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)
unsigned long flags;
struct blkio_group *blkg;
void *key;
+ struct blkio_policy_type *blkiop;
rcu_read_lock();
remove_entry:
@@ -249,7 +258,10 @@ remove_entry:
* we have more policies in place, we need some dynamic registration
* of callback function.
*/
- cfq_unlink_blkio_group(key, blkg);
+ spin_lock(&blkio_list_lock);
+ list_for_each_entry(blkiop, &blkio_list, list)
+ blkiop->ops.blkio_unlink_group_fn(key, blkg);
+ spin_unlock(&blkio_list_lock);
goto remove_entry;
done:
free_css_id(&blkio_subsys, &blkcg->css);
@@ -330,3 +342,19 @@ struct cgroup_subsys blkio_subsys = {
.subsys_id = blkio_subsys_id,
.use_id = 1,
};
+
+void blkio_policy_register(struct blkio_policy_type *blkiop)
+{
+ spin_lock(&blkio_list_lock);
+ list_add_tail(&blkiop->list, &blkio_list);
+ spin_unlock(&blkio_list_lock);
+}
+EXPORT_SYMBOL_GPL(blkio_policy_register);
+
+void blkio_policy_unregister(struct blkio_policy_type *blkiop)
+{
+ spin_lock(&blkio_list_lock);
+ list_del_init(&blkiop->list);
+ spin_unlock(&blkio_list_lock);
+}
+EXPORT_SYMBOL_GPL(blkio_policy_unregister);
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 4f89b967467..4d316df863b 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -46,11 +46,35 @@ struct blkio_group {
extern bool blkiocg_css_tryget(struct blkio_cgroup *blkcg);
extern void blkiocg_css_put(struct blkio_cgroup *blkcg);
+typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
+typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
+ unsigned int weight);
+
+struct blkio_policy_ops {
+ blkio_unlink_group_fn *blkio_unlink_group_fn;
+ blkio_update_group_weight_fn *blkio_update_group_weight_fn;
+};
+
+struct blkio_policy_type {
+ struct list_head list;
+ struct blkio_policy_ops ops;
+};
+
+/* Blkio controller policy registration */
+extern void blkio_policy_register(struct blkio_policy_type *);
+extern void blkio_policy_unregister(struct blkio_policy_type *);
+
#else
struct blkio_group {
};
+struct blkio_policy_type {
+};
+
+static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
+static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
+
#endif
#define BLKIO_WEIGHT_MIN 100
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 7f3f343b0c6..78f4829895b 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -14,7 +14,6 @@
#include <linux/ioprio.h>
#include <linux/blktrace_api.h>
#include "blk-cgroup.h"
-#include "cfq-iosched.h"
/*
* tunables
@@ -3855,6 +3854,17 @@ static struct elevator_type iosched_cfq = {
.elevator_owner = THIS_MODULE,
};
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+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,
+ },
+};
+#else
+static struct blkio_policy_type blkio_policy_cfq;
+#endif
+
static int __init cfq_init(void)
{
/*
@@ -3869,6 +3879,7 @@ static int __init cfq_init(void)
return -ENOMEM;
elv_register(&iosched_cfq);
+ blkio_policy_register(&blkio_policy_cfq);
return 0;
}
@@ -3876,6 +3887,7 @@ static int __init cfq_init(void)
static void __exit cfq_exit(void)
{
DECLARE_COMPLETION_ONSTACK(all_gone);
+ blkio_policy_unregister(&blkio_policy_cfq);
elv_unregister(&iosched_cfq);
ioc_gone = &all_gone;
/* ioc_gone's update must be visible before reading ioc_count */
diff --git a/block/cfq-iosched.h b/block/cfq-iosched.h
deleted file mode 100644
index ef7b4798a34..00000000000
--- a/block/cfq-iosched.h
+++ /dev/null
@@ -1,7 +0,0 @@
-#ifndef CFQ_IOSCHED_H
-#define CFQ_IOSCHED_H
-
-void cfq_unlink_blkio_group(void *, struct blkio_group *);
-void cfq_update_blkio_group_weight(struct blkio_group *, unsigned int);
-
-#endif