[PATCH] io-controller: implement per group request allocation limitation
From: Gui Jianfeng
Date: Thu Jul 09 2009 - 21:57:16 EST
Hi Vivek,
This patch exports a cgroup based per group request limits interface.
and removes the global one. Now we can use this interface to perform
different request allocation limitation for different groups.
Signed-off-by: Gui Jianfeng <guijianfeng@xxxxxxxxxxxxxx>
---
block/blk-core.c | 23 ++++++++++--
block/blk-settings.c | 1 -
block/blk-sysfs.c | 43 -----------------------
block/elevator-fq.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++---
block/elevator-fq.h | 4 ++
5 files changed, 111 insertions(+), 54 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 79fe6a9..7010b76 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -722,13 +722,20 @@ static void ioc_set_batching(struct request_queue *q, struct io_context *ioc)
static void __freed_request(struct request_queue *q, int sync,
struct request_list *rl)
{
+ struct io_group *iog;
+ unsigned long nr_group_requests;
+
if (q->rq_data.count[sync] < queue_congestion_off_threshold(q))
blk_clear_queue_congested(q, sync);
if (q->rq_data.count[sync] + 1 <= q->nr_requests)
blk_clear_queue_full(q, sync);
- if (rl->count[sync] + 1 <= q->nr_group_requests) {
+ iog = rl_iog(rl);
+
+ nr_group_requests = get_group_requests(q, iog);
+
+ if (nr_group_requests && rl->count[sync] + 1 <= nr_group_requests) {
if (waitqueue_active(&rl->wait[sync]))
wake_up(&rl->wait[sync]);
}
@@ -828,6 +835,8 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
const bool is_sync = rw_is_sync(rw_flags) != 0;
int may_queue, priv;
int sleep_on_global = 0;
+ struct io_group *iog;
+ unsigned long nr_group_requests;
may_queue = elv_may_queue(q, rw_flags);
if (may_queue == ELV_MQUEUE_NO)
@@ -843,7 +852,12 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
if (q->rq_data.count[is_sync]+1 >= q->nr_requests)
blk_set_queue_full(q, is_sync);
- if (rl->count[is_sync]+1 >= q->nr_group_requests) {
+ iog = rl_iog(rl);
+
+ nr_group_requests = get_group_requests(q, iog);
+
+ if (nr_group_requests &&
+ rl->count[is_sync]+1 >= nr_group_requests) {
ioc = current_io_context(GFP_ATOMIC, q->node);
/*
* The queue request descriptor group will fill after this
@@ -852,7 +866,7 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
* This process will be allowed to complete a batch of
* requests, others will be blocked.
*/
- if (rl->count[is_sync] <= q->nr_group_requests)
+ if (rl->count[is_sync] <= nr_group_requests)
ioc_set_batching(q, ioc);
else {
if (may_queue != ELV_MQUEUE_MUST
@@ -898,7 +912,8 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
* from per group request list
*/
- if (rl->count[is_sync] >= (3 * q->nr_group_requests / 2))
+ if (nr_group_requests &&
+ rl->count[is_sync] >= (3 * nr_group_requests / 2))
goto out;
rl->starved[is_sync] = 0;
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 78b8aec..bd582a7 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -148,7 +148,6 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
* set defaults
*/
q->nr_requests = BLKDEV_MAX_RQ;
- q->nr_group_requests = BLKDEV_MAX_GROUP_RQ;
q->make_request_fn = mfn;
blk_queue_dma_alignment(q, 511);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 92b9f25..706d852 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -78,40 +78,8 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count)
return ret;
}
#ifdef CONFIG_GROUP_IOSCHED
-static ssize_t queue_group_requests_show(struct request_queue *q, char *page)
-{
- return queue_var_show(q->nr_group_requests, (page));
-}
-
extern void elv_io_group_congestion_threshold(struct request_queue *q,
struct io_group *iog);
-
-static ssize_t
-queue_group_requests_store(struct request_queue *q, const char *page,
- size_t count)
-{
- struct hlist_node *n;
- struct io_group *iog;
- struct elv_fq_data *efqd;
- unsigned long nr;
- int ret = queue_var_store(&nr, page, count);
-
- if (nr < BLKDEV_MIN_RQ)
- nr = BLKDEV_MIN_RQ;
-
- spin_lock_irq(q->queue_lock);
-
- q->nr_group_requests = nr;
-
- efqd = &q->elevator->efqd;
-
- hlist_for_each_entry(iog, n, &efqd->group_list, elv_data_node) {
- elv_io_group_congestion_threshold(q, iog);
- }
-
- spin_unlock_irq(q->queue_lock);
- return ret;
-}
#endif
static ssize_t queue_ra_show(struct request_queue *q, char *page)
@@ -278,14 +246,6 @@ static struct queue_sysfs_entry queue_requests_entry = {
.store = queue_requests_store,
};
-#ifdef CONFIG_GROUP_IOSCHED
-static struct queue_sysfs_entry queue_group_requests_entry = {
- .attr = {.name = "nr_group_requests", .mode = S_IRUGO | S_IWUSR },
- .show = queue_group_requests_show,
- .store = queue_group_requests_store,
-};
-#endif
-
static struct queue_sysfs_entry queue_ra_entry = {
.attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
.show = queue_ra_show,
@@ -360,9 +320,6 @@ static struct queue_sysfs_entry queue_iostats_entry = {
static struct attribute *default_attrs[] = {
&queue_requests_entry.attr,
-#ifdef CONFIG_GROUP_IOSCHED
- &queue_group_requests_entry.attr,
-#endif
&queue_ra_entry.attr,
&queue_max_hw_sectors_entry.attr,
&queue_max_sectors_entry.attr,
diff --git a/block/elevator-fq.c b/block/elevator-fq.c
index 29392e7..bfb0210 100644
--- a/block/elevator-fq.c
+++ b/block/elevator-fq.c
@@ -59,6 +59,35 @@ elv_release_ioq(struct elevator_queue *eq, struct io_queue **ioq_ptr);
#define for_each_entity_safe(entity, parent) \
for (; entity && ({ parent = entity->parent; 1; }); entity = parent)
+unsigned short get_group_requests(struct request_queue *q,
+ struct io_group *iog)
+{
+ struct cgroup_subsys_state *css;
+ struct io_cgroup *iocg;
+ unsigned long nr_group_requests;
+
+ if (!iog)
+ return q->nr_requests;
+
+ rcu_read_lock();
+
+ if (!iog->iocg_id) {
+ nr_group_requests = 0;
+ goto out;
+ }
+
+ css = css_lookup(&io_subsys, iog->iocg_id);
+ if (!css) {
+ nr_group_requests = 0;
+ goto out;
+ }
+
+ iocg = container_of(css, struct io_cgroup, css);
+ nr_group_requests = iocg->nr_group_requests;
+out:
+ rcu_read_unlock();
+ return nr_group_requests;
+}
static struct io_entity *bfq_lookup_next_entity(struct io_sched_data *sd,
int extract);
@@ -1257,14 +1286,17 @@ void elv_io_group_congestion_threshold(struct request_queue *q,
struct io_group *iog)
{
int nr;
+ unsigned long nr_group_requests;
- nr = q->nr_group_requests - (q->nr_group_requests / 8) + 1;
- if (nr > q->nr_group_requests)
- nr = q->nr_group_requests;
+ nr_group_requests = get_group_requests(q, iog);
+
+ nr = nr_group_requests - (nr_group_requests / 8) + 1;
+ if (nr > nr_group_requests)
+ nr = nr_group_requests;
iog->nr_congestion_on = nr;
- nr = q->nr_group_requests - (q->nr_group_requests / 8)
- - (q->nr_group_requests / 16) - 1;
+ nr = nr_group_requests - (nr_group_requests / 8)
+ - (nr_group_requests / 16) - 1;
if (nr < 1)
nr = 1;
iog->nr_congestion_off = nr;
@@ -1283,6 +1315,7 @@ int elv_io_group_congested(struct request_queue *q, struct page *page, int sync)
{
struct io_group *iog;
int ret = 0;
+ unsigned long nr_group_requests;
rcu_read_lock();
@@ -1300,10 +1333,11 @@ int elv_io_group_congested(struct request_queue *q, struct page *page, int sync)
}
ret = elv_is_iog_congested(q, iog, sync);
+ nr_group_requests = get_group_requests(q, iog);
if (ret)
elv_log_iog(&q->elevator->efqd, iog, "iog congested=%d sync=%d"
" rl.count[sync]=%d nr_group_requests=%d",
- ret, sync, iog->rl.count[sync], q->nr_group_requests);
+ ret, sync, iog->rl.count[sync], nr_group_requests);
rcu_read_unlock();
return ret;
}
@@ -1549,6 +1583,48 @@ free_buf:
return ret;
}
+static u64 io_cgroup_nr_requests_read(struct cgroup *cgroup,
+ struct cftype *cftype)
+{
+ struct io_cgroup *iocg;
+ u64 ret;
+
+ if (!cgroup_lock_live_group(cgroup))
+ return -ENODEV;
+
+ iocg = cgroup_to_io_cgroup(cgroup);
+ spin_lock_irq(&iocg->lock);
+ ret = iocg->nr_group_requests;
+ spin_unlock_irq(&iocg->lock);
+
+ cgroup_unlock();
+
+ return ret;
+}
+
+static int io_cgroup_nr_requests_write(struct cgroup *cgroup,
+ struct cftype *cftype,
+ u64 val)
+{
+ struct io_cgroup *iocg;
+
+ if (val < BLKDEV_MIN_RQ)
+ val = BLKDEV_MIN_RQ;
+
+ if (!cgroup_lock_live_group(cgroup))
+ return -ENODEV;
+
+ iocg = cgroup_to_io_cgroup(cgroup);
+
+ spin_lock_irq(&iocg->lock);
+ iocg->nr_group_requests = (unsigned long)val;
+ spin_unlock_irq(&iocg->lock);
+
+ cgroup_unlock();
+
+ return 0;
+}
+
#define SHOW_FUNCTION(__VAR) \
static u64 io_cgroup_##__VAR##_read(struct cgroup *cgroup, \
struct cftype *cftype) \
@@ -1735,6 +1811,11 @@ static int io_cgroup_disk_dequeue_read(struct cgroup *cgroup,
struct cftype bfqio_files[] = {
{
+ .name = "nr_group_requests",
+ .read_u64 = io_cgroup_nr_requests_read,
+ .write_u64 = io_cgroup_nr_requests_write,
+ },
+ {
.name = "policy",
.read_seq_string = io_cgroup_policy_read,
.write_string = io_cgroup_policy_write,
@@ -1790,6 +1871,7 @@ static struct cgroup_subsys_state *iocg_create(struct cgroup_subsys *subsys,
spin_lock_init(&iocg->lock);
INIT_HLIST_HEAD(&iocg->group_data);
+ iocg->nr_group_requests = BLKDEV_MAX_GROUP_RQ;
iocg->weight = IO_DEFAULT_GRP_WEIGHT;
iocg->ioprio_class = IO_DEFAULT_GRP_CLASS;
INIT_LIST_HEAD(&iocg->policy_list);
diff --git a/block/elevator-fq.h b/block/elevator-fq.h
index f089a55..df077d0 100644
--- a/block/elevator-fq.h
+++ b/block/elevator-fq.h
@@ -308,6 +308,7 @@ struct io_cgroup {
unsigned int weight;
unsigned short ioprio_class;
+ unsigned long nr_group_requests;
/* list of io_policy_node */
struct list_head policy_list;
@@ -386,6 +387,9 @@ struct elv_fq_data {
unsigned int fairness;
};
+extern unsigned short get_group_requests(struct request_queue *q,
+ struct io_group *iog);
+
/* Logging facilities. */
#ifdef CONFIG_DEBUG_GROUP_IOSCHED
#define elv_log_ioq(efqd, ioq, fmt, args...) \
--
1.5.4.rc3
--
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