* [PATCH 1/7] blk-cgroup: Kill the header printed at the start of blkio.weight_device file
2010-09-15 21:06 [RFC PATCH] Block device bio throttling support [V3] Vivek Goyal
@ 2010-09-15 21:06 ` Vivek Goyal
2010-09-15 21:06 ` [PATCH 2/7] blk-cgroup: Prepare the base for supporting more than one IO control policies Vivek Goyal
` (7 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Vivek Goyal @ 2010-09-15 21:06 UTC (permalink / raw)
To: linux-kernel, axboe; +Cc: nauman, dpshah, guijianfeng, vgoyal
o Kill extra "dev weight" header which is printed when somebody reads
blkio.weight_device file. This really seems to be out of convention. No other
blkio files are printing any header at the start of file. I think it is ok
to just print values and how to interpret values should be part of
documentation.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-cgroup.c | 2 --
1 files changed, 0 insertions(+), 2 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 2fef1ef..e3d2506 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -811,8 +811,6 @@ static int blkiocg_weight_device_read(struct cgroup *cgrp, struct cftype *cft,
struct blkio_cgroup *blkcg;
struct blkio_policy_node *pn;
- seq_printf(m, "dev\tweight\n");
-
blkcg = cgroup_to_blkio_cgroup(cgrp);
if (!list_empty(&blkcg->policy_list)) {
spin_lock_irq(&blkcg->lock);
--
1.7.2.3
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 2/7] blk-cgroup: Prepare the base for supporting more than one IO control policies
2010-09-15 21:06 [RFC PATCH] Block device bio throttling support [V3] Vivek Goyal
2010-09-15 21:06 ` [PATCH 1/7] blk-cgroup: Kill the header printed at the start of blkio.weight_device file Vivek Goyal
@ 2010-09-15 21:06 ` Vivek Goyal
2010-09-15 21:06 ` [PATCH 3/7] blk-cgroup: Introduce cgroup changes for throttling policy Vivek Goyal
` (6 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Vivek Goyal @ 2010-09-15 21:06 UTC (permalink / raw)
To: linux-kernel, axboe; +Cc: nauman, dpshah, guijianfeng, vgoyal
o This patch prepares the base for introducing new IO control policies.
Currently all the code is written knowing there is only one policy
and that is proportional bandwidth. Creating infrastructure for newer
policies to come in.
o Also there were many functions which were generated using macro. It was
very confusing. Got rid of those.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-cgroup.c | 544 +++++++++++++++++++++++++++++++++++++--------------
block/blk-cgroup.h | 36 ++++-
block/cfq-iosched.c | 1 +
block/cfq.h | 2 +-
4 files changed, 429 insertions(+), 154 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index e3d2506..0a15a7a 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -37,6 +37,12 @@ static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *,
static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *);
static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *);
+/* for encoding cft->private value on file */
+#define BLKIOFILE_PRIVATE(x, val) (((x) << 16) | (val))
+/* What policy owns the file, proportional or throttle */
+#define BLKIOFILE_POLICY(val) (((val) >> 16) & 0xffff)
+#define BLKIOFILE_ATTR(val) ((val) & 0xffff)
+
struct cgroup_subsys blkio_subsys = {
.name = "blkio",
.create = blkiocg_create,
@@ -59,6 +65,27 @@ static inline void blkio_policy_insert_node(struct blkio_cgroup *blkcg,
list_add(&pn->node, &blkcg->policy_list);
}
+static inline bool cftype_blkg_same_policy(struct cftype *cft,
+ struct blkio_group *blkg)
+{
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+
+ if (blkg->plid == plid)
+ return 1;
+
+ return 0;
+}
+
+/* Determines if policy node matches cgroup file being accessed */
+static inline bool pn_matches_cftype(struct cftype *cft,
+ struct blkio_policy_node *pn)
+{
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int fileid = BLKIOFILE_ATTR(cft->private);
+
+ return (plid == pn->plid && fileid == pn->fileid);
+}
+
/* Must be called with blkcg->lock held */
static inline void blkio_policy_delete_node(struct blkio_policy_node *pn)
{
@@ -67,12 +94,13 @@ static inline void blkio_policy_delete_node(struct blkio_policy_node *pn)
/* Must be called with blkcg->lock held */
static struct blkio_policy_node *
-blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev)
+blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev,
+ enum blkio_policy_id plid, int fileid)
{
struct blkio_policy_node *pn;
list_for_each_entry(pn, &blkcg->policy_list, node) {
- if (pn->dev == dev)
+ if (pn->dev == dev && pn->plid == plid && pn->fileid == fileid)
return pn;
}
@@ -86,6 +114,20 @@ struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup)
}
EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
+static inline void
+blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight)
+{
+ struct blkio_policy_type *blkiop;
+
+ list_for_each_entry(blkiop, &blkio_list, list) {
+ /* If this policy does not own the blkg, do not send updates */
+ if (blkiop->plid != blkg->plid)
+ continue;
+ if (blkiop->ops.blkio_update_group_weight_fn)
+ blkiop->ops.blkio_update_group_weight_fn(blkg, weight);
+ }
+}
+
/*
* Add to the appropriate stat variable depending on the request type.
* This should be called with the blkg->stats_lock held.
@@ -341,7 +383,8 @@ void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats);
void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
- struct blkio_group *blkg, void *key, dev_t dev)
+ struct blkio_group *blkg, void *key, dev_t dev,
+ enum blkio_policy_id plid)
{
unsigned long flags;
@@ -350,6 +393,7 @@ void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
rcu_assign_pointer(blkg->key, key);
blkg->blkcg_id = css_id(&blkcg->css);
hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
+ blkg->plid = plid;
spin_unlock_irqrestore(&blkcg->lock, flags);
/* Need to take css reference ? */
cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));
@@ -408,51 +452,6 @@ struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key)
}
EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
-#define SHOW_FUNCTION(__VAR) \
-static u64 blkiocg_##__VAR##_read(struct cgroup *cgroup, \
- struct cftype *cftype) \
-{ \
- struct blkio_cgroup *blkcg; \
- \
- blkcg = cgroup_to_blkio_cgroup(cgroup); \
- return (u64)blkcg->__VAR; \
-}
-
-SHOW_FUNCTION(weight);
-#undef SHOW_FUNCTION
-
-static int
-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;
- struct blkio_policy_node *pn;
-
- if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX)
- return -EINVAL;
-
- blkcg = cgroup_to_blkio_cgroup(cgroup);
- spin_lock(&blkio_list_lock);
- spin_lock_irq(&blkcg->lock);
- blkcg->weight = (unsigned int)val;
-
- hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
- pn = blkio_policy_search_node(blkcg, blkg->dev);
-
- if (pn)
- continue;
-
- list_for_each_entry(blkiop, &blkio_list, list)
- blkiop->ops.blkio_update_group_weight_fn(blkg,
- blkcg->weight);
- }
- spin_unlock_irq(&blkcg->lock);
- spin_unlock(&blkio_list_lock);
- return 0;
-}
-
static int
blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
{
@@ -593,52 +592,6 @@ static uint64_t blkio_get_stat(struct blkio_group *blkg,
return disk_total;
}
-#define SHOW_FUNCTION_PER_GROUP(__VAR, type, show_total) \
-static int blkiocg_##__VAR##_read(struct cgroup *cgroup, \
- struct cftype *cftype, struct cgroup_map_cb *cb) \
-{ \
- struct blkio_cgroup *blkcg; \
- struct blkio_group *blkg; \
- struct hlist_node *n; \
- uint64_t cgroup_total = 0; \
- \
- if (!cgroup_lock_live_group(cgroup)) \
- return -ENODEV; \
- \
- blkcg = cgroup_to_blkio_cgroup(cgroup); \
- rcu_read_lock(); \
- hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {\
- if (blkg->dev) { \
- spin_lock_irq(&blkg->stats_lock); \
- cgroup_total += blkio_get_stat(blkg, cb, \
- blkg->dev, type); \
- spin_unlock_irq(&blkg->stats_lock); \
- } \
- } \
- if (show_total) \
- cb->fill(cb, "Total", cgroup_total); \
- rcu_read_unlock(); \
- cgroup_unlock(); \
- return 0; \
-}
-
-SHOW_FUNCTION_PER_GROUP(time, BLKIO_STAT_TIME, 0);
-SHOW_FUNCTION_PER_GROUP(sectors, BLKIO_STAT_SECTORS, 0);
-SHOW_FUNCTION_PER_GROUP(io_service_bytes, BLKIO_STAT_SERVICE_BYTES, 1);
-SHOW_FUNCTION_PER_GROUP(io_serviced, BLKIO_STAT_SERVICED, 1);
-SHOW_FUNCTION_PER_GROUP(io_service_time, BLKIO_STAT_SERVICE_TIME, 1);
-SHOW_FUNCTION_PER_GROUP(io_wait_time, BLKIO_STAT_WAIT_TIME, 1);
-SHOW_FUNCTION_PER_GROUP(io_merged, BLKIO_STAT_MERGED, 1);
-SHOW_FUNCTION_PER_GROUP(io_queued, BLKIO_STAT_QUEUED, 1);
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-SHOW_FUNCTION_PER_GROUP(dequeue, BLKIO_STAT_DEQUEUE, 0);
-SHOW_FUNCTION_PER_GROUP(avg_queue_size, BLKIO_STAT_AVG_QUEUE_SIZE, 0);
-SHOW_FUNCTION_PER_GROUP(group_wait_time, BLKIO_STAT_GROUP_WAIT_TIME, 0);
-SHOW_FUNCTION_PER_GROUP(idle_time, BLKIO_STAT_IDLE_TIME, 0);
-SHOW_FUNCTION_PER_GROUP(empty_time, BLKIO_STAT_EMPTY_TIME, 0);
-#endif
-#undef SHOW_FUNCTION_PER_GROUP
-
static int blkio_check_dev_num(dev_t dev)
{
int part = 0;
@@ -652,7 +605,7 @@ static int blkio_check_dev_num(dev_t dev)
}
static int blkio_policy_parse_and_set(char *buf,
- struct blkio_policy_node *newpn)
+ struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid)
{
char *s[4], *p, *major_s = NULL, *minor_s = NULL;
int ret;
@@ -705,12 +658,20 @@ static int blkio_policy_parse_and_set(char *buf,
if (s[1] == NULL)
return -EINVAL;
- ret = strict_strtoul(s[1], 10, &temp);
- if (ret || (temp < BLKIO_WEIGHT_MIN && temp > 0) ||
- temp > BLKIO_WEIGHT_MAX)
- return -EINVAL;
+ switch (plid) {
+ case BLKIO_POLICY_PROP:
+ ret = strict_strtoul(s[1], 10, &temp);
+ if (ret || (temp < BLKIO_WEIGHT_MIN && temp > 0) ||
+ temp > BLKIO_WEIGHT_MAX)
+ return -EINVAL;
- newpn->weight = temp;
+ newpn->plid = plid;
+ newpn->fileid = fileid;
+ newpn->weight = temp;
+ break;
+ default:
+ BUG();
+ }
return 0;
}
@@ -720,7 +681,8 @@ unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
{
struct blkio_policy_node *pn;
- pn = blkio_policy_search_node(blkcg, dev);
+ pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP,
+ BLKIO_PROP_weight_device);
if (pn)
return pn->weight;
else
@@ -728,18 +690,86 @@ unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
}
EXPORT_SYMBOL_GPL(blkcg_get_weight);
+/* Checks whether user asked for deleting a policy rule */
+static bool blkio_delete_rule_command(struct blkio_policy_node *pn)
+{
+ switch(pn->plid) {
+ case BLKIO_POLICY_PROP:
+ if (pn->weight == 0)
+ return 1;
+ break;
+ default:
+ BUG();
+ }
+
+ return 0;
+}
+
+static void blkio_update_policy_rule(struct blkio_policy_node *oldpn,
+ struct blkio_policy_node *newpn)
+{
+ switch(oldpn->plid) {
+ case BLKIO_POLICY_PROP:
+ oldpn->weight = newpn->weight;
+ break;
+ default:
+ BUG();
+ }
+}
+
+/*
+ * Some rules/values in blkg have changed. Propogate those to respective
+ * policies.
+ */
+static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg,
+ struct blkio_group *blkg, struct blkio_policy_node *pn)
+{
+ unsigned int weight;
+
+ switch(pn->plid) {
+ case BLKIO_POLICY_PROP:
+ weight = pn->weight ? pn->weight :
+ blkcg->weight;
+ blkio_update_group_weight(blkg, weight);
+ break;
+ default:
+ BUG();
+ }
+}
-static int blkiocg_weight_device_write(struct cgroup *cgrp, struct cftype *cft,
- const char *buffer)
+/*
+ * A policy node rule has been updated. Propogate this update to all the
+ * block groups which might be affected by this update.
+ */
+static void blkio_update_policy_node_blkg(struct blkio_cgroup *blkcg,
+ struct blkio_policy_node *pn)
+{
+ struct blkio_group *blkg;
+ struct hlist_node *n;
+
+ spin_lock(&blkio_list_lock);
+ spin_lock_irq(&blkcg->lock);
+
+ hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
+ if (pn->dev != blkg->dev || pn->plid != blkg->plid)
+ continue;
+ blkio_update_blkg_policy(blkcg, blkg, pn);
+ }
+
+ spin_unlock_irq(&blkcg->lock);
+ spin_unlock(&blkio_list_lock);
+}
+
+static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft,
+ const char *buffer)
{
int ret = 0;
char *buf;
struct blkio_policy_node *newpn, *pn;
struct blkio_cgroup *blkcg;
- struct blkio_group *blkg;
int keep_newpn = 0;
- struct hlist_node *n;
- struct blkio_policy_type *blkiop;
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int fileid = BLKIOFILE_ATTR(cft->private);
buf = kstrdup(buffer, GFP_KERNEL);
if (!buf)
@@ -751,7 +781,7 @@ static int blkiocg_weight_device_write(struct cgroup *cgrp, struct cftype *cft,
goto free_buf;
}
- ret = blkio_policy_parse_and_set(buf, newpn);
+ ret = blkio_policy_parse_and_set(buf, newpn, plid, fileid);
if (ret)
goto free_newpn;
@@ -759,9 +789,9 @@ static int blkiocg_weight_device_write(struct cgroup *cgrp, struct cftype *cft,
spin_lock_irq(&blkcg->lock);
- pn = blkio_policy_search_node(blkcg, newpn->dev);
+ pn = blkio_policy_search_node(blkcg, newpn->dev, plid, fileid);
if (!pn) {
- if (newpn->weight != 0) {
+ if (!blkio_delete_rule_command(newpn)) {
blkio_policy_insert_node(blkcg, newpn);
keep_newpn = 1;
}
@@ -769,33 +799,17 @@ static int blkiocg_weight_device_write(struct cgroup *cgrp, struct cftype *cft,
goto update_io_group;
}
- if (newpn->weight == 0) {
- /* weight == 0 means deleteing a specific weight */
+ if (blkio_delete_rule_command(newpn)) {
blkio_policy_delete_node(pn);
spin_unlock_irq(&blkcg->lock);
goto update_io_group;
}
spin_unlock_irq(&blkcg->lock);
- pn->weight = newpn->weight;
+ blkio_update_policy_rule(pn, newpn);
update_io_group:
- /* update weight for each cfqg */
- spin_lock(&blkio_list_lock);
- spin_lock_irq(&blkcg->lock);
-
- hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
- if (newpn->dev == blkg->dev) {
- list_for_each_entry(blkiop, &blkio_list, list)
- blkiop->ops.blkio_update_group_weight_fn(blkg,
- newpn->weight ?
- newpn->weight :
- blkcg->weight);
- }
- }
-
- spin_unlock_irq(&blkcg->lock);
- spin_unlock(&blkio_list_lock);
+ blkio_update_policy_node_blkg(blkcg, newpn);
free_newpn:
if (!keep_newpn)
@@ -805,21 +819,219 @@ free_buf:
return ret;
}
-static int blkiocg_weight_device_read(struct cgroup *cgrp, struct cftype *cft,
- struct seq_file *m)
+static void
+blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn)
+{
+ switch(pn->plid) {
+ case BLKIO_POLICY_PROP:
+ if (pn->fileid == BLKIO_PROP_weight_device)
+ seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
+ MINOR(pn->dev), pn->weight);
+ break;
+ default:
+ BUG();
+ }
+}
+
+/* cgroup files which read their data from policy nodes end up here */
+static void blkio_read_policy_node_files(struct cftype *cft,
+ struct blkio_cgroup *blkcg, struct seq_file *m)
{
- struct blkio_cgroup *blkcg;
struct blkio_policy_node *pn;
- blkcg = cgroup_to_blkio_cgroup(cgrp);
if (!list_empty(&blkcg->policy_list)) {
spin_lock_irq(&blkcg->lock);
list_for_each_entry(pn, &blkcg->policy_list, node) {
- seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
- MINOR(pn->dev), pn->weight);
+ if (!pn_matches_cftype(cft, pn))
+ continue;
+ blkio_print_policy_node(m, pn);
}
spin_unlock_irq(&blkcg->lock);
}
+}
+
+static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft,
+ struct seq_file *m)
+{
+ struct blkio_cgroup *blkcg;
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int name = BLKIOFILE_ATTR(cft->private);
+
+ blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+ switch(plid) {
+ case BLKIO_POLICY_PROP:
+ switch(name) {
+ case BLKIO_PROP_weight_device:
+ blkio_read_policy_node_files(cft, blkcg, m);
+ return 0;
+ default:
+ BUG();
+ }
+ break;
+ default:
+ BUG();
+ }
+
+ return 0;
+}
+
+static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg,
+ struct cftype *cft, struct cgroup_map_cb *cb, enum stat_type type,
+ bool show_total)
+{
+ struct blkio_group *blkg;
+ struct hlist_node *n;
+ uint64_t cgroup_total = 0;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {
+ if (blkg->dev) {
+ if (!cftype_blkg_same_policy(cft, blkg))
+ continue;
+ spin_lock_irq(&blkg->stats_lock);
+ cgroup_total += blkio_get_stat(blkg, cb, blkg->dev,
+ type);
+ spin_unlock_irq(&blkg->stats_lock);
+ }
+ }
+ if (show_total)
+ cb->fill(cb, "Total", cgroup_total);
+ rcu_read_unlock();
+ return 0;
+}
+
+/* All map kind of cgroup file get serviced by this function */
+static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft,
+ struct cgroup_map_cb *cb)
+{
+ struct blkio_cgroup *blkcg;
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int name = BLKIOFILE_ATTR(cft->private);
+
+ blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+ switch(plid) {
+ case BLKIO_POLICY_PROP:
+ switch(name) {
+ case BLKIO_PROP_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_TIME, 0);
+ case BLKIO_PROP_sectors:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_SECTORS, 0);
+ case BLKIO_PROP_io_service_bytes:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_SERVICE_BYTES, 1);
+ case BLKIO_PROP_io_serviced:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_SERVICED, 1);
+ case BLKIO_PROP_io_service_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_SERVICE_TIME, 1);
+ case BLKIO_PROP_io_wait_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_WAIT_TIME, 1);
+ case BLKIO_PROP_io_merged:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_MERGED, 1);
+ case BLKIO_PROP_io_queued:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_QUEUED, 1);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ case BLKIO_PROP_dequeue:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_DEQUEUE, 0);
+ case BLKIO_PROP_avg_queue_size:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_AVG_QUEUE_SIZE, 0);
+ case BLKIO_PROP_group_wait_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_GROUP_WAIT_TIME, 0);
+ case BLKIO_PROP_idle_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_IDLE_TIME, 0);
+ case BLKIO_PROP_empty_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_EMPTY_TIME, 0);
+#endif
+ default:
+ BUG();
+ }
+ break;
+
+ default:
+ BUG();
+ }
+
+ return 0;
+}
+
+static int blkio_weight_write(struct blkio_cgroup *blkcg, u64 val)
+{
+ struct blkio_group *blkg;
+ struct hlist_node *n;
+ struct blkio_policy_node *pn;
+
+ if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX)
+ return -EINVAL;
+
+ spin_lock(&blkio_list_lock);
+ spin_lock_irq(&blkcg->lock);
+ blkcg->weight = (unsigned int)val;
+
+ hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
+ pn = blkio_policy_search_node(blkcg, blkg->dev,
+ BLKIO_POLICY_PROP, BLKIO_PROP_weight_device);
+ if (pn)
+ continue;
+
+ blkio_update_group_weight(blkg, blkcg->weight);
+ }
+ spin_unlock_irq(&blkcg->lock);
+ spin_unlock(&blkio_list_lock);
+ return 0;
+}
+
+static u64 blkiocg_file_read_u64 (struct cgroup *cgrp, struct cftype *cft) {
+ struct blkio_cgroup *blkcg;
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int name = BLKIOFILE_ATTR(cft->private);
+
+ blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+ switch(plid) {
+ case BLKIO_POLICY_PROP:
+ switch(name) {
+ case BLKIO_PROP_weight:
+ return (u64)blkcg->weight;
+ }
+ break;
+ default:
+ BUG();
+ }
+ return 0;
+}
+
+static int
+blkiocg_file_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
+{
+ struct blkio_cgroup *blkcg;
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int name = BLKIOFILE_ATTR(cft->private);
+
+ blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+ switch(plid) {
+ case BLKIO_POLICY_PROP:
+ switch(name) {
+ case BLKIO_PROP_weight:
+ return blkio_weight_write(blkcg, val);
+ }
+ break;
+ default:
+ BUG();
+ }
return 0;
}
@@ -827,46 +1039,66 @@ static int blkiocg_weight_device_read(struct cgroup *cgrp, struct cftype *cft,
struct cftype blkio_files[] = {
{
.name = "weight_device",
- .read_seq_string = blkiocg_weight_device_read,
- .write_string = blkiocg_weight_device_write,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_weight_device),
+ .read_seq_string = blkiocg_file_read,
+ .write_string = blkiocg_file_write,
.max_write_len = 256,
},
{
.name = "weight",
- .read_u64 = blkiocg_weight_read,
- .write_u64 = blkiocg_weight_write,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_weight),
+ .read_u64 = blkiocg_file_read_u64,
+ .write_u64 = blkiocg_file_write_u64,
},
{
.name = "time",
- .read_map = blkiocg_time_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_time),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "sectors",
- .read_map = blkiocg_sectors_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_sectors),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "io_service_bytes",
- .read_map = blkiocg_io_service_bytes_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_service_bytes),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "io_serviced",
- .read_map = blkiocg_io_serviced_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_serviced),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "io_service_time",
- .read_map = blkiocg_io_service_time_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_service_time),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "io_wait_time",
- .read_map = blkiocg_io_wait_time_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_wait_time),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "io_merged",
- .read_map = blkiocg_io_merged_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_merged),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "io_queued",
- .read_map = blkiocg_io_queued_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_queued),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "reset_stats",
@@ -875,23 +1107,33 @@ struct cftype blkio_files[] = {
#ifdef CONFIG_DEBUG_BLK_CGROUP
{
.name = "avg_queue_size",
- .read_map = blkiocg_avg_queue_size_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_avg_queue_size),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "group_wait_time",
- .read_map = blkiocg_group_wait_time_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_group_wait_time),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "idle_time",
- .read_map = blkiocg_idle_time_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_idle_time),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "empty_time",
- .read_map = blkiocg_empty_time_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_empty_time),
+ .read_map = blkiocg_file_read_map,
},
{
.name = "dequeue",
- .read_map = blkiocg_dequeue_read,
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_dequeue),
+ .read_map = blkiocg_file_read_map,
},
#endif
};
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 2b866ec..c8de259 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -15,6 +15,10 @@
#include <linux/cgroup.h>
+enum blkio_policy_id {
+ BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
+};
+
#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
#ifndef CONFIG_BLK_CGROUP
@@ -65,6 +69,25 @@ enum blkg_state_flags {
BLKG_empty,
};
+/* cgroup files owned by proportional weight policy */
+enum blkcg_file_name_prop {
+ BLKIO_PROP_weight = 1,
+ BLKIO_PROP_weight_device,
+ BLKIO_PROP_io_service_bytes,
+ BLKIO_PROP_io_serviced,
+ BLKIO_PROP_time,
+ BLKIO_PROP_sectors,
+ BLKIO_PROP_io_service_time,
+ BLKIO_PROP_io_wait_time,
+ BLKIO_PROP_io_merged,
+ BLKIO_PROP_io_queued,
+ BLKIO_PROP_avg_queue_size,
+ BLKIO_PROP_group_wait_time,
+ BLKIO_PROP_idle_time,
+ BLKIO_PROP_empty_time,
+ BLKIO_PROP_dequeue,
+};
+
struct blkio_cgroup {
struct cgroup_subsys_state css;
unsigned int weight;
@@ -112,6 +135,8 @@ struct blkio_group {
char path[128];
/* The device MKDEV(major, minor), this group has been created for */
dev_t dev;
+ /* policy which owns this blk group */
+ enum blkio_policy_id plid;
/* Need to serialize the stats in the case of reset/update */
spinlock_t stats_lock;
@@ -122,6 +147,10 @@ struct blkio_policy_node {
struct list_head node;
dev_t dev;
unsigned int weight;
+ /* This node belongs to max bw policy or porportional weight policy */
+ enum blkio_policy_id plid;
+ /* cgroup file to which this rule belongs to */
+ int fileid;
};
extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
@@ -139,6 +168,7 @@ struct blkio_policy_ops {
struct blkio_policy_type {
struct list_head list;
struct blkio_policy_ops ops;
+ enum blkio_policy_id plid;
};
/* Blkio controller policy registration */
@@ -212,7 +242,8 @@ static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
extern struct blkio_cgroup blkio_root_cgroup;
extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
- struct blkio_group *blkg, void *key, dev_t dev);
+ struct blkio_group *blkg, void *key, dev_t dev,
+ enum blkio_policy_id plid);
extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
void *key);
@@ -234,7 +265,8 @@ static inline struct blkio_cgroup *
cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
- struct blkio_group *blkg, void *key, dev_t dev) {}
+ struct blkio_group *blkg, void *key, dev_t dev,
+ enum blkio_policy_id plid) {}
static inline int
blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index f65c6f0..38278d4 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -4080,6 +4080,7 @@ static struct blkio_policy_type blkio_policy_cfq = {
.blkio_unlink_group_fn = cfq_unlink_blkio_group,
.blkio_update_group_weight_fn = cfq_update_blkio_group_weight,
},
+ .plid = BLKIO_POLICY_PROP,
};
#else
static struct blkio_policy_type blkio_policy_cfq;
diff --git a/block/cfq.h b/block/cfq.h
index 93448e5..54a6d90 100644
--- a/block/cfq.h
+++ b/block/cfq.h
@@ -69,7 +69,7 @@ static inline void cfq_blkiocg_update_completion_stats(struct blkio_group *blkg,
static inline void cfq_blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
struct blkio_group *blkg, void *key, dev_t dev) {
- blkiocg_add_blkio_group(blkcg, blkg, key, dev);
+ blkiocg_add_blkio_group(blkcg, blkg, key, dev, BLKIO_POLICY_PROP);
}
static inline int cfq_blkiocg_del_blkio_group(struct blkio_group *blkg)
--
1.7.2.3
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 3/7] blk-cgroup: Introduce cgroup changes for throttling policy
2010-09-15 21:06 [RFC PATCH] Block device bio throttling support [V3] Vivek Goyal
2010-09-15 21:06 ` [PATCH 1/7] blk-cgroup: Kill the header printed at the start of blkio.weight_device file Vivek Goyal
2010-09-15 21:06 ` [PATCH 2/7] blk-cgroup: Prepare the base for supporting more than one IO control policies Vivek Goyal
@ 2010-09-15 21:06 ` Vivek Goyal
2010-09-15 21:06 ` [PATCH 4/7] blkio: Core implementation of throttle policy Vivek Goyal
` (5 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Vivek Goyal @ 2010-09-15 21:06 UTC (permalink / raw)
To: linux-kernel, axboe; +Cc: nauman, dpshah, guijianfeng, vgoyal
o cgroup chagnes for throttle policy.
o Introduces READ and WRITE bytes per second throttling rules.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-cgroup.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++++---
block/blk-cgroup.h | 30 ++++++++++-
2 files changed, 167 insertions(+), 8 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0a15a7a..32b5920 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -128,6 +128,27 @@ blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight)
}
}
+static inline void blkio_update_group_bps(struct blkio_group *blkg, u64 bps,
+ int fileid)
+{
+ struct blkio_policy_type *blkiop;
+
+ list_for_each_entry(blkiop, &blkio_list, list) {
+
+ /* If this policy does not own the blkg, do not send updates */
+ if (blkiop->plid != blkg->plid)
+ continue;
+
+ if (fileid == BLKIO_THROTL_read_bps_device
+ && blkiop->ops.blkio_update_group_read_bps_fn)
+ blkiop->ops.blkio_update_group_read_bps_fn(blkg, bps);
+
+ if (fileid == BLKIO_THROTL_write_bps_device
+ && blkiop->ops.blkio_update_group_write_bps_fn)
+ blkiop->ops.blkio_update_group_write_bps_fn(blkg, bps);
+ }
+}
+
/*
* Add to the appropriate stat variable depending on the request type.
* This should be called with the blkg->stats_lock held.
@@ -612,6 +633,7 @@ static int blkio_policy_parse_and_set(char *buf,
unsigned long major, minor, temp;
int i = 0;
dev_t dev;
+ u64 bps;
memset(s, 0, sizeof(s));
@@ -667,7 +689,16 @@ static int blkio_policy_parse_and_set(char *buf,
newpn->plid = plid;
newpn->fileid = fileid;
- newpn->weight = temp;
+ newpn->val.weight = temp;
+ break;
+ case BLKIO_POLICY_THROTL:
+ ret = strict_strtoull(s[1], 10, &bps);
+ if (ret)
+ return -EINVAL;
+
+ newpn->plid = plid;
+ newpn->fileid = fileid;
+ newpn->val.bps = bps;
break;
default:
BUG();
@@ -684,18 +715,45 @@ unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP,
BLKIO_PROP_weight_device);
if (pn)
- return pn->weight;
+ return pn->val.weight;
else
return blkcg->weight;
}
EXPORT_SYMBOL_GPL(blkcg_get_weight);
+uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev)
+{
+ struct blkio_policy_node *pn;
+
+ pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_read_bps_device);
+ if (pn)
+ return pn->val.bps;
+ else
+ return -1;
+}
+
+uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev)
+{
+ struct blkio_policy_node *pn;
+ pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_write_bps_device);
+ if (pn)
+ return pn->val.bps;
+ else
+ return -1;
+}
+
/* Checks whether user asked for deleting a policy rule */
static bool blkio_delete_rule_command(struct blkio_policy_node *pn)
{
switch(pn->plid) {
case BLKIO_POLICY_PROP:
- if (pn->weight == 0)
+ if (pn->val.weight == 0)
+ return 1;
+ break;
+ case BLKIO_POLICY_THROTL:
+ if (pn->val.bps == 0)
return 1;
break;
default:
@@ -710,7 +768,10 @@ static void blkio_update_policy_rule(struct blkio_policy_node *oldpn,
{
switch(oldpn->plid) {
case BLKIO_POLICY_PROP:
- oldpn->weight = newpn->weight;
+ oldpn->val.weight = newpn->val.weight;
+ break;
+ case BLKIO_POLICY_THROTL:
+ oldpn->val.bps = newpn->val.bps;
break;
default:
BUG();
@@ -725,13 +786,23 @@ static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg,
struct blkio_group *blkg, struct blkio_policy_node *pn)
{
unsigned int weight;
+ u64 bps;
switch(pn->plid) {
case BLKIO_POLICY_PROP:
- weight = pn->weight ? pn->weight :
+ weight = pn->val.weight ? pn->val.weight :
blkcg->weight;
blkio_update_group_weight(blkg, weight);
break;
+ case BLKIO_POLICY_THROTL:
+ switch(pn->fileid) {
+ case BLKIO_THROTL_read_bps_device:
+ case BLKIO_THROTL_write_bps_device:
+ bps = pn->val.bps ? pn->val.bps : (-1);
+ blkio_update_group_bps(blkg, bps, pn->fileid);
+ break;
+ }
+ break;
default:
BUG();
}
@@ -826,7 +897,17 @@ blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn)
case BLKIO_POLICY_PROP:
if (pn->fileid == BLKIO_PROP_weight_device)
seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
- MINOR(pn->dev), pn->weight);
+ MINOR(pn->dev), pn->val.weight);
+ break;
+ case BLKIO_POLICY_THROTL:
+ if (pn->fileid == BLKIO_THROTL_read_bps_device)
+ seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev),
+ MINOR(pn->dev), pn->val.bps);
+ else if (pn->fileid == BLKIO_THROTL_write_bps_device)
+ seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev),
+ MINOR(pn->dev), pn->val.bps);
+ else
+ BUG();
break;
default:
BUG();
@@ -869,6 +950,16 @@ static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft,
BUG();
}
break;
+ case BLKIO_POLICY_THROTL:
+ switch(name){
+ case BLKIO_THROTL_read_bps_device:
+ case BLKIO_THROTL_write_bps_device:
+ blkio_read_policy_node_files(cft, blkcg, m);
+ return 0;
+ default:
+ BUG();
+ }
+ break;
default:
BUG();
}
@@ -959,7 +1050,18 @@ static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft,
BUG();
}
break;
-
+ case BLKIO_POLICY_THROTL:
+ switch(name){
+ case BLKIO_THROTL_io_service_bytes:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_SERVICE_BYTES, 1);
+ case BLKIO_THROTL_io_serviced:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_SERVICED, 1);
+ default:
+ BUG();
+ }
+ break;
default:
BUG();
}
@@ -1053,6 +1155,23 @@ struct cftype blkio_files[] = {
.write_u64 = blkiocg_file_write_u64,
},
{
+ .name = "throttle.read_bps_device",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_read_bps_device),
+ .read_seq_string = blkiocg_file_read,
+ .write_string = blkiocg_file_write,
+ .max_write_len = 256,
+ },
+
+ {
+ .name = "throttle.write_bps_device",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_write_bps_device),
+ .read_seq_string = blkiocg_file_read,
+ .write_string = blkiocg_file_write,
+ .max_write_len = 256,
+ },
+ {
.name = "time",
.private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
BLKIO_PROP_time),
@@ -1071,12 +1190,24 @@ struct cftype blkio_files[] = {
.read_map = blkiocg_file_read_map,
},
{
+ .name = "throttle.io_service_bytes",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_io_service_bytes),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
.name = "io_serviced",
.private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
BLKIO_PROP_io_serviced),
.read_map = blkiocg_file_read_map,
},
{
+ .name = "throttle.io_serviced",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_io_serviced),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
.name = "io_service_time",
.private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
BLKIO_PROP_io_service_time),
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index c8de259..1b73882 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -17,6 +17,7 @@
enum blkio_policy_id {
BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
+ BLKIO_POLICY_THROTL, /* Throttling */
};
#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
@@ -88,6 +89,14 @@ enum blkcg_file_name_prop {
BLKIO_PROP_dequeue,
};
+/* cgroup files owned by throttle policy */
+enum blkcg_file_name_throtl {
+ BLKIO_THROTL_read_bps_device,
+ BLKIO_THROTL_write_bps_device,
+ BLKIO_THROTL_io_service_bytes,
+ BLKIO_THROTL_io_serviced,
+};
+
struct blkio_cgroup {
struct cgroup_subsys_state css;
unsigned int weight;
@@ -146,23 +155,42 @@ struct blkio_group {
struct blkio_policy_node {
struct list_head node;
dev_t dev;
- unsigned int weight;
/* This node belongs to max bw policy or porportional weight policy */
enum blkio_policy_id plid;
/* cgroup file to which this rule belongs to */
int fileid;
+
+ union {
+ unsigned int weight;
+ /*
+ * Rate read/write in terms of byptes per second
+ * Whether this rate represents read or write is determined
+ * by file type "fileid".
+ */
+ u64 bps;
+ } val;
};
extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
dev_t dev);
+extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
+ dev_t dev);
+extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
+ dev_t dev);
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);
+typedef void (blkio_update_group_read_bps_fn) (struct blkio_group *blkg,
+ u64 read_bps);
+typedef void (blkio_update_group_write_bps_fn) (struct blkio_group *blkg,
+ u64 write_bps);
struct blkio_policy_ops {
blkio_unlink_group_fn *blkio_unlink_group_fn;
blkio_update_group_weight_fn *blkio_update_group_weight_fn;
+ blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
+ blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
};
struct blkio_policy_type {
--
1.7.2.3
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 4/7] blkio: Core implementation of throttle policy
2010-09-15 21:06 [RFC PATCH] Block device bio throttling support [V3] Vivek Goyal
` (2 preceding siblings ...)
2010-09-15 21:06 ` [PATCH 3/7] blk-cgroup: Introduce cgroup changes for throttling policy Vivek Goyal
@ 2010-09-15 21:06 ` Vivek Goyal
2010-09-15 21:06 ` [PATCH 5/7] blk-cgroup: cgroup changes for IOPS limit support Vivek Goyal
` (4 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Vivek Goyal @ 2010-09-15 21:06 UTC (permalink / raw)
To: linux-kernel, axboe; +Cc: nauman, dpshah, guijianfeng, vgoyal
o Actual implementation of throttling policy in block layer. Currently it
implements READ and WRITE bytes per second throttling logic. IOPS throttling
comes in later patches.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
block/Kconfig | 12 +
block/Makefile | 1 +
block/blk-core.c | 24 ++
block/blk-throttle.c | 909 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/blk_types.h | 3 +
include/linux/blkdev.h | 24 ++
init/Kconfig | 9 +-
7 files changed, 979 insertions(+), 3 deletions(-)
create mode 100644 block/blk-throttle.c
diff --git a/block/Kconfig b/block/Kconfig
index 9be0b56..6c9213e 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -77,6 +77,18 @@ config BLK_DEV_INTEGRITY
T10/SCSI Data Integrity Field or the T13/ATA External Path
Protection. If in doubt, say N.
+config BLK_DEV_THROTTLING
+ bool "Block layer bio throttling support"
+ depends on BLK_CGROUP=y && EXPERIMENTAL
+ default n
+ ---help---
+ Block layer bio throttling support. It can be used to limit
+ the IO rate to a device. IO rate policies are per cgroup and
+ one needs to mount and use blkio cgroup controller for creating
+ cgroups and specifying per device IO rate policies.
+
+ See Documentation/cgroups/blkio-controller.txt for more information.
+
endif # BLOCK
config BLOCK_COMPAT
diff --git a/block/Makefile b/block/Makefile
index 0bb499a..c850d5e 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \
obj-$(CONFIG_BLK_DEV_BSG) += bsg.o
obj-$(CONFIG_BLK_CGROUP) += blk-cgroup.o
+obj-$(CONFIG_BLK_DEV_THROTTLING) += blk-throttle.o
obj-$(CONFIG_IOSCHED_NOOP) += noop-iosched.o
obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o
obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o
diff --git a/block/blk-core.c b/block/blk-core.c
index 32a1c12..fac6dd2 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -382,6 +382,7 @@ void blk_sync_queue(struct request_queue *q)
del_timer_sync(&q->unplug_timer);
del_timer_sync(&q->timeout);
cancel_work_sync(&q->unplug_work);
+ throtl_shutdown_timer_wq(q);
}
EXPORT_SYMBOL(blk_sync_queue);
@@ -459,6 +460,8 @@ void blk_cleanup_queue(struct request_queue *q)
if (q->elevator)
elevator_exit(q->elevator);
+ blk_throtl_exit(q);
+
blk_put_queue(q);
}
EXPORT_SYMBOL(blk_cleanup_queue);
@@ -515,6 +518,11 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
return NULL;
}
+ if (blk_throtl_init(q)) {
+ kmem_cache_free(blk_requestq_cachep, q);
+ return NULL;
+ }
+
setup_timer(&q->backing_dev_info.laptop_mode_wb_timer,
laptop_mode_timer_fn, (unsigned long) q);
init_timer(&q->unplug_timer);
@@ -1522,6 +1530,15 @@ static inline void __generic_make_request(struct bio *bio)
goto end_io;
}
+ blk_throtl_bio(q, &bio);
+
+ /*
+ * If bio = NULL, bio has been throttled and will be submitted
+ * later.
+ */
+ if (!bio)
+ break;
+
trace_block_bio_queue(q, bio);
ret = q->make_request_fn(q, bio);
@@ -2579,6 +2596,13 @@ int kblockd_schedule_work(struct request_queue *q, struct work_struct *work)
}
EXPORT_SYMBOL(kblockd_schedule_work);
+int kblockd_schedule_delayed_work(struct request_queue *q,
+ struct delayed_work *dwork, unsigned long delay)
+{
+ return queue_delayed_work(kblockd_workqueue, dwork, delay);
+}
+EXPORT_SYMBOL(kblockd_schedule_delayed_work);
+
int __init blk_dev_init(void)
{
BUILD_BUG_ON(__REQ_NR_BITS > 8 *
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
new file mode 100644
index 0000000..966afc7
--- /dev/null
+++ b/block/blk-throttle.c
@@ -0,0 +1,909 @@
+/*
+ * Interface for controlling IO bandwidth on a request queue
+ *
+ * Copyright (C) 2010 Vivek Goyal <vgoyal@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/blktrace_api.h>
+#include "blk-cgroup.h"
+
+/* Max dispatch from a group in 1 round */
+static int throtl_grp_quantum = 8;
+
+/* Total max dispatch from all groups in one round */
+static int throtl_quantum = 32;
+
+/* Throttling is performed over 100ms slice and after that slice is renewed */
+static unsigned long throtl_slice = HZ/10; /* 100 ms */
+
+struct throtl_rb_root {
+ struct rb_root rb;
+ struct rb_node *left;
+ unsigned int count;
+ unsigned long min_disptime;
+};
+
+#define THROTL_RB_ROOT (struct throtl_rb_root) { .rb = RB_ROOT, .left = NULL, \
+ .count = 0, .min_disptime = 0}
+
+#define rb_entry_tg(node) rb_entry((node), struct throtl_grp, rb_node)
+
+struct throtl_grp {
+ /* List of throtl groups on the request queue*/
+ struct hlist_node tg_node;
+
+ /* active throtl group service_tree member */
+ struct rb_node rb_node;
+
+ /*
+ * Dispatch time in jiffies. This is the estimated time when group
+ * will unthrottle and is ready to dispatch more bio. It is used as
+ * key to sort active groups in service tree.
+ */
+ unsigned long disptime;
+
+ struct blkio_group blkg;
+ atomic_t ref;
+ unsigned int flags;
+
+ /* Two lists for READ and WRITE */
+ struct bio_list bio_lists[2];
+
+ /* Number of queued bios on READ and WRITE lists */
+ unsigned int nr_queued[2];
+
+ /* bytes per second rate limits */
+ uint64_t bps[2];
+
+ /* Number of bytes disptached in current slice */
+ uint64_t bytes_disp[2];
+
+ /* When did we start a new slice */
+ unsigned long slice_start[2];
+ unsigned long slice_end[2];
+};
+
+struct throtl_data
+{
+ /* List of throtl groups */
+ struct hlist_head tg_list;
+
+ /* service tree for active throtl groups */
+ struct throtl_rb_root tg_service_tree;
+
+ struct throtl_grp root_tg;
+ struct request_queue *queue;
+
+ /* Total Number of queued bios on READ and WRITE lists */
+ unsigned int nr_queued[2];
+
+ /*
+ * number of total undestroyed groups (excluding root group)
+ */
+ unsigned int nr_undestroyed_grps;
+
+ /* Work for dispatching throttled bios */
+ struct delayed_work throtl_work;
+};
+
+enum tg_state_flags {
+ THROTL_TG_FLAG_on_rr = 0, /* on round-robin busy list */
+};
+
+#define THROTL_TG_FNS(name) \
+static inline void throtl_mark_tg_##name(struct throtl_grp *tg) \
+{ \
+ (tg)->flags |= (1 << THROTL_TG_FLAG_##name); \
+} \
+static inline void throtl_clear_tg_##name(struct throtl_grp *tg) \
+{ \
+ (tg)->flags &= ~(1 << THROTL_TG_FLAG_##name); \
+} \
+static inline int throtl_tg_##name(const struct throtl_grp *tg) \
+{ \
+ return ((tg)->flags & (1 << THROTL_TG_FLAG_##name)) != 0; \
+}
+
+THROTL_TG_FNS(on_rr);
+
+#define throtl_log_tg(td, tg, fmt, args...) \
+ blk_add_trace_msg((td)->queue, "throtl %s " fmt, \
+ blkg_path(&(tg)->blkg), ##args); \
+
+#define throtl_log(td, fmt, args...) \
+ blk_add_trace_msg((td)->queue, "throtl " fmt, ##args)
+
+static inline struct throtl_grp *tg_of_blkg(struct blkio_group *blkg)
+{
+ if (blkg)
+ return container_of(blkg, struct throtl_grp, blkg);
+
+ return NULL;
+}
+
+static inline int total_nr_queued(struct throtl_data *td)
+{
+ return (td->nr_queued[0] + td->nr_queued[1]);
+}
+
+static inline struct throtl_grp *throtl_ref_get_tg(struct throtl_grp *tg)
+{
+ atomic_inc(&tg->ref);
+ return tg;
+}
+
+static void throtl_put_tg(struct throtl_grp *tg)
+{
+ BUG_ON(atomic_read(&tg->ref) <= 0);
+ if (!atomic_dec_and_test(&tg->ref))
+ return;
+ kfree(tg);
+}
+
+static struct throtl_grp * throtl_find_alloc_tg(struct throtl_data *td,
+ struct cgroup *cgroup)
+{
+ struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
+ struct throtl_grp *tg = NULL;
+ void *key = td;
+ struct backing_dev_info *bdi = &td->queue->backing_dev_info;
+ unsigned int major, minor;
+
+ /*
+ * TODO: Speed up blkiocg_lookup_group() by maintaining a radix
+ * tree of blkg (instead of traversing through hash list all
+ * the time.
+ */
+ tg = tg_of_blkg(blkiocg_lookup_group(blkcg, key));
+
+ /* Fill in device details for root group */
+ if (tg && !tg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
+ sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
+ tg->blkg.dev = MKDEV(major, minor);
+ goto done;
+ }
+
+ if (tg)
+ goto done;
+
+ tg = kzalloc_node(sizeof(*tg), GFP_ATOMIC, td->queue->node);
+ if (!tg)
+ goto done;
+
+ INIT_HLIST_NODE(&tg->tg_node);
+ RB_CLEAR_NODE(&tg->rb_node);
+ bio_list_init(&tg->bio_lists[0]);
+ bio_list_init(&tg->bio_lists[1]);
+
+ /*
+ * Take the initial reference that will be released on destroy
+ * This can be thought of a joint reference by cgroup and
+ * request queue which will be dropped by either request queue
+ * exit or cgroup deletion path depending on who is exiting first.
+ */
+ atomic_set(&tg->ref, 1);
+
+ /* Add group onto cgroup list */
+ sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
+ blkiocg_add_blkio_group(blkcg, &tg->blkg, (void *)td,
+ MKDEV(major, minor), BLKIO_POLICY_THROTL);
+
+ tg->bps[READ] = blkcg_get_read_bps(blkcg, tg->blkg.dev);
+ tg->bps[WRITE] = blkcg_get_write_bps(blkcg, tg->blkg.dev);
+
+ hlist_add_head(&tg->tg_node, &td->tg_list);
+ td->nr_undestroyed_grps++;
+done:
+ return tg;
+}
+
+static struct throtl_grp * throtl_get_tg(struct throtl_data *td)
+{
+ struct cgroup *cgroup;
+ struct throtl_grp *tg = NULL;
+
+ rcu_read_lock();
+ cgroup = task_cgroup(current, blkio_subsys_id);
+ tg = throtl_find_alloc_tg(td, cgroup);
+ if (!tg)
+ tg = &td->root_tg;
+ rcu_read_unlock();
+ return tg;
+}
+
+static struct throtl_grp *throtl_rb_first(struct throtl_rb_root *root)
+{
+ /* Service tree is empty */
+ if (!root->count)
+ return NULL;
+
+ if (!root->left)
+ root->left = rb_first(&root->rb);
+
+ if (root->left)
+ return rb_entry_tg(root->left);
+
+ return NULL;
+}
+
+static void rb_erase_init(struct rb_node *n, struct rb_root *root)
+{
+ rb_erase(n, root);
+ RB_CLEAR_NODE(n);
+}
+
+static void throtl_rb_erase(struct rb_node *n, struct throtl_rb_root *root)
+{
+ if (root->left == n)
+ root->left = NULL;
+ rb_erase_init(n, &root->rb);
+ --root->count;
+}
+
+static void update_min_dispatch_time(struct throtl_rb_root *st)
+{
+ struct throtl_grp *tg;
+
+ tg = throtl_rb_first(st);
+ if (!tg)
+ return;
+
+ st->min_disptime = tg->disptime;
+}
+
+static void
+tg_service_tree_add(struct throtl_rb_root *st, struct throtl_grp *tg)
+{
+ struct rb_node **node = &st->rb.rb_node;
+ struct rb_node *parent = NULL;
+ struct throtl_grp *__tg;
+ unsigned long key = tg->disptime;
+ int left = 1;
+
+ while (*node != NULL) {
+ parent = *node;
+ __tg = rb_entry_tg(parent);
+
+ if (time_before(key, __tg->disptime))
+ node = &parent->rb_left;
+ else {
+ node = &parent->rb_right;
+ left = 0;
+ }
+ }
+
+ if (left)
+ st->left = &tg->rb_node;
+
+ rb_link_node(&tg->rb_node, parent, node);
+ rb_insert_color(&tg->rb_node, &st->rb);
+}
+
+static void __throtl_enqueue_tg(struct throtl_data *td, struct throtl_grp *tg)
+{
+ struct throtl_rb_root *st = &td->tg_service_tree;
+
+ tg_service_tree_add(st, tg);
+ throtl_mark_tg_on_rr(tg);
+ st->count++;
+}
+
+static void throtl_enqueue_tg(struct throtl_data *td, struct throtl_grp *tg)
+{
+ if (!throtl_tg_on_rr(tg))
+ __throtl_enqueue_tg(td, tg);
+}
+
+static void __throtl_dequeue_tg(struct throtl_data *td, struct throtl_grp *tg)
+{
+ throtl_rb_erase(&tg->rb_node, &td->tg_service_tree);
+ throtl_clear_tg_on_rr(tg);
+}
+
+static void throtl_dequeue_tg(struct throtl_data *td, struct throtl_grp *tg)
+{
+ if (throtl_tg_on_rr(tg))
+ __throtl_dequeue_tg(td, tg);
+}
+
+static void throtl_schedule_next_dispatch(struct throtl_data *td)
+{
+ struct throtl_rb_root *st = &td->tg_service_tree;
+
+ /*
+ * If there are more bios pending, schedule more work.
+ */
+ if (!total_nr_queued(td))
+ return;
+
+ BUG_ON(!st->count);
+
+ update_min_dispatch_time(st);
+
+ if (time_before_eq(st->min_disptime, jiffies))
+ throtl_schedule_delayed_work(td->queue, 0);
+ else
+ throtl_schedule_delayed_work(td->queue,
+ (st->min_disptime - jiffies));
+}
+
+static inline void
+throtl_start_new_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
+{
+ tg->bytes_disp[rw] = 0;
+ tg->slice_start[rw] = jiffies;
+ tg->slice_end[rw] = jiffies + throtl_slice;
+ throtl_log_tg(td, tg, "[%c] new slice start=%lu end=%lu jiffies=%lu",
+ rw == READ ? 'R' : 'W', tg->slice_start[rw],
+ tg->slice_end[rw], jiffies);
+}
+
+static inline void throtl_extend_slice(struct throtl_data *td,
+ struct throtl_grp *tg, bool rw, unsigned long jiffy_end)
+{
+ tg->slice_end[rw] = roundup(jiffy_end, throtl_slice);
+ throtl_log_tg(td, tg, "[%c] extend slice start=%lu end=%lu jiffies=%lu",
+ rw == READ ? 'R' : 'W', tg->slice_start[rw],
+ tg->slice_end[rw], jiffies);
+}
+
+/* Determine if previously allocated or extended slice is complete or not */
+static bool
+throtl_slice_used(struct throtl_data *td, struct throtl_grp *tg, bool rw)
+{
+ if (time_in_range(jiffies, tg->slice_start[rw], tg->slice_end[rw]))
+ return 0;
+
+ return 1;
+}
+
+/* Trim the used slices and adjust slice start accordingly */
+static inline void
+throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
+{
+ unsigned long nr_slices, bytes_trim, time_elapsed;
+
+ BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw]));
+
+ /*
+ * If bps are unlimited (-1), then time slice don't get
+ * renewed. Don't try to trim the slice if slice is used. A new
+ * slice will start when appropriate.
+ */
+ if (throtl_slice_used(td, tg, rw))
+ return;
+
+ time_elapsed = jiffies - tg->slice_start[rw];
+
+ nr_slices = time_elapsed / throtl_slice;
+
+ if (!nr_slices)
+ return;
+
+ bytes_trim = (tg->bps[rw] * throtl_slice * nr_slices)/HZ;
+
+ if (!bytes_trim)
+ return;
+
+ if (tg->bytes_disp[rw] >= bytes_trim)
+ tg->bytes_disp[rw] -= bytes_trim;
+ else
+ tg->bytes_disp[rw] = 0;
+
+ tg->slice_start[rw] += nr_slices * throtl_slice;
+
+ throtl_log_tg(td, tg, "[%c] trim slice nr=%lu bytes=%lu"
+ " start=%lu end=%lu jiffies=%lu",
+ rw == READ ? 'R' : 'W', nr_slices, bytes_trim,
+ tg->slice_start[rw], tg->slice_end[rw], jiffies);
+}
+
+/*
+ * Returns whether one can dispatch a bio or not. Also returns approx number
+ * of jiffies to wait before this bio is with-in IO rate and can be dispatched
+ */
+static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg,
+ struct bio *bio, unsigned long *wait)
+{
+ bool rw = bio_data_dir(bio);
+ u64 bytes_allowed, extra_bytes;
+ unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd;
+
+ /*
+ * Currently whole state machine of group depends on first bio
+ * queued in the group bio list. So one should not be calling
+ * this function with a different bio if there are other bios
+ * queued.
+ */
+ BUG_ON(tg->nr_queued[rw] && bio != bio_list_peek(&tg->bio_lists[rw]));
+
+ /* If tg->bps = -1, then BW is unlimited */
+ if (tg->bps[rw] == -1) {
+ if (wait)
+ *wait = 0;
+ return 1;
+ }
+
+ /*
+ * If previous slice expired, start a new one otherwise renew/extend
+ * existing slice to make sure it is at least throtl_slice interval
+ * long since now.
+ */
+ if (throtl_slice_used(td, tg, rw))
+ throtl_start_new_slice(td, tg, rw);
+ else {
+ if (time_before(tg->slice_end[rw], jiffies + throtl_slice))
+ throtl_extend_slice(td, tg, rw, jiffies + throtl_slice);
+ }
+
+ jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw];
+
+ /* Slice has just started. Consider one slice interval */
+ if (!jiffy_elapsed)
+ jiffy_elapsed_rnd = throtl_slice;
+
+ jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, throtl_slice);
+
+ bytes_allowed = (tg->bps[rw] * jiffies_to_msecs(jiffy_elapsed_rnd))
+ / MSEC_PER_SEC;
+
+ if (tg->bytes_disp[rw] + bio->bi_size <= bytes_allowed) {
+ if (wait)
+ *wait = 0;
+ return 1;
+ }
+
+ /* Calc approx time to dispatch */
+ extra_bytes = tg->bytes_disp[rw] + bio->bi_size - bytes_allowed;
+ jiffy_wait = div64_u64(extra_bytes * HZ, tg->bps[rw]);
+
+ if (!jiffy_wait)
+ jiffy_wait = 1;
+
+ /*
+ * This wait time is without taking into consideration the rounding
+ * up we did. Add that time also.
+ */
+ jiffy_wait = jiffy_wait + (jiffy_elapsed_rnd - jiffy_elapsed);
+
+ if (wait)
+ *wait = jiffy_wait;
+
+ if (time_before(tg->slice_end[rw], jiffies + jiffy_wait))
+ throtl_extend_slice(td, tg, rw, jiffies + jiffy_wait);
+
+ return 0;
+}
+
+static void throtl_charge_bio(struct throtl_grp *tg, struct bio *bio)
+{
+ bool rw = bio_data_dir(bio);
+ bool sync = bio->bi_rw & REQ_SYNC;
+
+ /* Charge the bio to the group */
+ tg->bytes_disp[rw] += bio->bi_size;
+
+ /*
+ * TODO: This will take blkg->stats_lock. Figure out a way
+ * to avoid this cost.
+ */
+ blkiocg_update_dispatch_stats(&tg->blkg, bio->bi_size, rw, sync);
+
+}
+
+static void throtl_add_bio_tg(struct throtl_data *td, struct throtl_grp *tg,
+ struct bio *bio)
+{
+ bool rw = bio_data_dir(bio);
+
+ bio_list_add(&tg->bio_lists[rw], bio);
+ /* Take a bio reference on tg */
+ throtl_ref_get_tg(tg);
+ tg->nr_queued[rw]++;
+ td->nr_queued[rw]++;
+ throtl_enqueue_tg(td, tg);
+}
+
+static void tg_update_disptime(struct throtl_data *td, struct throtl_grp *tg)
+{
+ unsigned long read_wait = -1, write_wait = -1, min_wait = -1, disptime;
+ struct bio *bio;
+
+ if ((bio = bio_list_peek(&tg->bio_lists[READ])))
+ tg_may_dispatch(td, tg, bio, &read_wait);
+
+ if ((bio = bio_list_peek(&tg->bio_lists[WRITE])))
+ tg_may_dispatch(td, tg, bio, &write_wait);
+
+ min_wait = min(read_wait, write_wait);
+ disptime = jiffies + min_wait;
+
+ /*
+ * If group is already on active tree, then update dispatch time
+ * only if it is lesser than existing dispatch time. Otherwise
+ * always update the dispatch time
+ */
+
+ if (throtl_tg_on_rr(tg) && time_before(disptime, tg->disptime))
+ return;
+
+ /* Update dispatch time */
+ throtl_dequeue_tg(td, tg);
+ tg->disptime = disptime;
+ throtl_enqueue_tg(td, tg);
+}
+
+static void tg_dispatch_one_bio(struct throtl_data *td, struct throtl_grp *tg,
+ bool rw, struct bio_list *bl)
+{
+ struct bio *bio;
+
+ bio = bio_list_pop(&tg->bio_lists[rw]);
+ tg->nr_queued[rw]--;
+ /* Drop bio reference on tg */
+ throtl_put_tg(tg);
+
+ BUG_ON(td->nr_queued[rw] <= 0);
+ td->nr_queued[rw]--;
+
+ throtl_charge_bio(tg, bio);
+ bio_list_add(bl, bio);
+ bio->bi_rw |= REQ_THROTTLED;
+
+ throtl_trim_slice(td, tg, rw);
+}
+
+static int throtl_dispatch_tg(struct throtl_data *td, struct throtl_grp *tg,
+ struct bio_list *bl)
+{
+ unsigned int nr_reads = 0, nr_writes = 0;
+ unsigned int max_nr_reads = throtl_grp_quantum*3/4;
+ unsigned int max_nr_writes = throtl_grp_quantum - nr_reads;
+ struct bio *bio;
+
+ /* Try to dispatch 75% READS and 25% WRITES */
+
+ while ((bio = bio_list_peek(&tg->bio_lists[READ]))
+ && tg_may_dispatch(td, tg, bio, NULL)) {
+
+ tg_dispatch_one_bio(td, tg, bio_data_dir(bio), bl);
+ nr_reads++;
+
+ if (nr_reads >= max_nr_reads)
+ break;
+ }
+
+ while ((bio = bio_list_peek(&tg->bio_lists[WRITE]))
+ && tg_may_dispatch(td, tg, bio, NULL)) {
+
+ tg_dispatch_one_bio(td, tg, bio_data_dir(bio), bl);
+ nr_writes++;
+
+ if (nr_writes >= max_nr_writes)
+ break;
+ }
+
+ return nr_reads + nr_writes;
+}
+
+static int throtl_select_dispatch(struct throtl_data *td, struct bio_list *bl)
+{
+ unsigned int nr_disp = 0;
+ struct throtl_grp *tg;
+ struct throtl_rb_root *st = &td->tg_service_tree;
+
+ while (1) {
+ tg = throtl_rb_first(st);
+
+ if (!tg)
+ break;
+
+ if (time_before(jiffies, tg->disptime))
+ break;
+
+ throtl_dequeue_tg(td, tg);
+
+ nr_disp += throtl_dispatch_tg(td, tg, bl);
+
+ if (tg->nr_queued[0] || tg->nr_queued[1]) {
+ tg_update_disptime(td, tg);
+ throtl_enqueue_tg(td, tg);
+ }
+
+ if (nr_disp >= throtl_quantum)
+ break;
+ }
+
+ return nr_disp;
+}
+
+/* Dispatch throttled bios. Should be called without queue lock held. */
+static int throtl_dispatch(struct request_queue *q)
+{
+ struct throtl_data *td = q->td;
+ unsigned int nr_disp = 0;
+ struct bio_list bio_list_on_stack;
+ struct bio *bio;
+
+ spin_lock_irq(q->queue_lock);
+
+ if (!total_nr_queued(td))
+ goto out;
+
+ bio_list_init(&bio_list_on_stack);
+
+ throtl_log(td, "dispatch nr_queued=%lu read=%u write=%u",
+ total_nr_queued(td), td->nr_queued[READ],
+ td->nr_queued[WRITE]);
+
+ nr_disp = throtl_select_dispatch(td, &bio_list_on_stack);
+
+ if (nr_disp)
+ throtl_log(td, "bios disp=%u", nr_disp);
+
+ throtl_schedule_next_dispatch(td);
+out:
+ spin_unlock_irq(q->queue_lock);
+
+ /*
+ * If we dispatched some requests, unplug the queue to make sure
+ * immediate dispatch
+ */
+ if (nr_disp) {
+ while((bio = bio_list_pop(&bio_list_on_stack)))
+ generic_make_request(bio);
+ blk_unplug(q);
+ }
+ return nr_disp;
+}
+
+void blk_throtl_work(struct work_struct *work)
+{
+ struct throtl_data *td = container_of(work, struct throtl_data,
+ throtl_work.work);
+ struct request_queue *q = td->queue;
+
+ throtl_dispatch(q);
+}
+
+/* Call with queue lock held */
+void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay)
+{
+
+ struct throtl_data *td = q->td;
+ struct delayed_work *dwork = &td->throtl_work;
+
+ if (total_nr_queued(td) > 0) {
+ /*
+ * We might have a work scheduled to be executed in future.
+ * Cancel that and schedule a new one.
+ */
+ __cancel_delayed_work(dwork);
+ kblockd_schedule_delayed_work(q, dwork, delay);
+ throtl_log(td, "schedule work. delay=%lu jiffies=%lu",
+ delay, jiffies);
+ }
+}
+EXPORT_SYMBOL(throtl_schedule_delayed_work);
+
+static void
+throtl_destroy_tg(struct throtl_data *td, struct throtl_grp *tg)
+{
+ /* Something wrong if we are trying to remove same group twice */
+ BUG_ON(hlist_unhashed(&tg->tg_node));
+
+ hlist_del_init(&tg->tg_node);
+
+ /*
+ * Put the reference taken at the time of creation so that when all
+ * queues are gone, group can be destroyed.
+ */
+ throtl_put_tg(tg);
+ td->nr_undestroyed_grps--;
+}
+
+static void throtl_release_tgs(struct throtl_data *td)
+{
+ struct hlist_node *pos, *n;
+ struct throtl_grp *tg;
+
+ hlist_for_each_entry_safe(tg, pos, n, &td->tg_list, tg_node) {
+ /*
+ * If cgroup removal path got to blk_group first and removed
+ * it from cgroup list, then it will take care of destroying
+ * cfqg also.
+ */
+ if (!blkiocg_del_blkio_group(&tg->blkg))
+ throtl_destroy_tg(td, tg);
+ }
+}
+
+static void throtl_td_free(struct throtl_data *td)
+{
+ kfree(td);
+}
+
+/*
+ * Blk cgroup controller notification saying that blkio_group object is being
+ * delinked as associated cgroup object is going away. That also means that
+ * no new IO will come in this group. So get rid of this group as soon as
+ * any pending IO in the group is finished.
+ *
+ * This function is called under rcu_read_lock(). key is the rcu protected
+ * pointer. That means "key" is a valid throtl_data pointer as long as we are
+ * rcu read lock.
+ *
+ * "key" was fetched from blkio_group under blkio_cgroup->lock. That means
+ * it should not be NULL as even if queue was going away, cgroup deltion
+ * path got to it first.
+ */
+void throtl_unlink_blkio_group(void *key, struct blkio_group *blkg)
+{
+ unsigned long flags;
+ struct throtl_data *td = key;
+
+ spin_lock_irqsave(td->queue->queue_lock, flags);
+ throtl_destroy_tg(td, tg_of_blkg(blkg));
+ spin_unlock_irqrestore(td->queue->queue_lock, flags);
+}
+
+static void throtl_update_blkio_group_read_bps (struct blkio_group *blkg,
+ u64 read_bps)
+{
+ tg_of_blkg(blkg)->bps[READ] = read_bps;
+}
+
+static void throtl_update_blkio_group_write_bps (struct blkio_group *blkg,
+ u64 write_bps)
+{
+ tg_of_blkg(blkg)->bps[WRITE] = write_bps;
+}
+
+void throtl_shutdown_timer_wq(struct request_queue *q)
+{
+ struct throtl_data *td = q->td;
+
+ cancel_delayed_work_sync(&td->throtl_work);
+}
+
+static struct blkio_policy_type blkio_policy_throtl = {
+ .ops = {
+ .blkio_unlink_group_fn = throtl_unlink_blkio_group,
+ .blkio_update_group_read_bps_fn =
+ throtl_update_blkio_group_read_bps,
+ .blkio_update_group_write_bps_fn =
+ throtl_update_blkio_group_write_bps,
+ },
+};
+
+int blk_throtl_bio(struct request_queue *q, struct bio **biop)
+{
+ struct throtl_data *td = q->td;
+ struct throtl_grp *tg;
+ struct bio *bio = *biop;
+ bool rw = bio_data_dir(bio), update_disptime = true;
+
+ if (bio->bi_rw & REQ_THROTTLED) {
+ bio->bi_rw &= ~REQ_THROTTLED;
+ return 0;
+ }
+
+ spin_lock_irq(q->queue_lock);
+ tg = throtl_get_tg(td);
+
+ if (tg->nr_queued[rw]) {
+ /*
+ * There is already another bio queued in same dir. No
+ * need to update dispatch time.
+ */
+ update_disptime = false;
+ goto queue_bio;
+ }
+
+ /* Bio is with-in rate limit of group */
+ if (tg_may_dispatch(td, tg, bio, NULL)) {
+ throtl_charge_bio(tg, bio);
+ goto out;
+ }
+
+queue_bio:
+ throtl_log_tg(td, tg, "[%c] bio. disp=%u sz=%u bps=%llu"
+ " queued=%d/%d", rw == READ ? 'R' : 'W',
+ tg->bytes_disp[rw], bio->bi_size, tg->bps[rw],
+ tg->nr_queued[READ], tg->nr_queued[WRITE]);
+
+ throtl_add_bio_tg(q->td, tg, bio);
+ *biop = NULL;
+
+ if (update_disptime) {
+ tg_update_disptime(td, tg);
+ throtl_schedule_next_dispatch(td);
+ }
+
+out:
+ spin_unlock_irq(q->queue_lock);
+ return 0;
+}
+
+int blk_throtl_init(struct request_queue *q)
+{
+ struct throtl_data *td;
+ struct throtl_grp *tg;
+
+ td = kzalloc_node(sizeof(*td), GFP_KERNEL, q->node);
+ if (!td)
+ return -ENOMEM;
+
+ INIT_HLIST_HEAD(&td->tg_list);
+ td->tg_service_tree = THROTL_RB_ROOT;
+
+ /* Init root group */
+ tg = &td->root_tg;
+ INIT_HLIST_NODE(&tg->tg_node);
+ RB_CLEAR_NODE(&tg->rb_node);
+ bio_list_init(&tg->bio_lists[0]);
+ bio_list_init(&tg->bio_lists[1]);
+
+ /* Practically unlimited BW */
+ tg->bps[0] = tg->bps[1] = -1;
+ atomic_set(&tg->ref, 1);
+
+ INIT_DELAYED_WORK(&td->throtl_work, blk_throtl_work);
+
+ rcu_read_lock();
+ blkiocg_add_blkio_group(&blkio_root_cgroup, &tg->blkg, (void *)td,
+ 0, BLKIO_POLICY_THROTL);
+ rcu_read_unlock();
+
+ /* Attach throtl data to request queue */
+ td->queue = q;
+ q->td = td;
+ return 0;
+}
+
+void blk_throtl_exit(struct request_queue *q)
+{
+ struct throtl_data *td = q->td;
+ bool wait = false;
+
+ BUG_ON(!td);
+
+ throtl_shutdown_timer_wq(q);
+
+ spin_lock_irq(q->queue_lock);
+ throtl_release_tgs(td);
+ blkiocg_del_blkio_group(&td->root_tg.blkg);
+
+ /* If there are other groups */
+ if (td->nr_undestroyed_grps >= 1)
+ wait = true;
+
+ spin_unlock_irq(q->queue_lock);
+
+ /*
+ * Wait for tg->blkg->key accessors to exit their grace periods.
+ * Do this wait only if there are other undestroyed groups out
+ * there (other than root group). This can happen if cgroup deletion
+ * path claimed the responsibility of cleaning up a group before
+ * queue cleanup code get to the group.
+ *
+ * Do not call synchronize_rcu() unconditionally as there are drivers
+ * which create/delete request queue hundreds of times during scan/boot
+ * and synchronize_rcu() can take significant time and slow down boot.
+ */
+ if (wait)
+ synchronize_rcu();
+ throtl_td_free(td);
+}
+
+static int __init throtl_init(void)
+{
+ blkio_policy_register(&blkio_policy_throtl);
+ return 0;
+}
+
+module_init(throtl_init);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index ca83a97..10a0c29 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -130,6 +130,8 @@ enum rq_flag_bits {
/* bio only flags */
__REQ_UNPLUG, /* unplug the immediately after submission */
__REQ_RAHEAD, /* read ahead, can fail anytime */
+ __REQ_THROTTLED, /* This bio has already been subjected to
+ * throttling rules. Don't do it again. */
/* request only flags */
__REQ_SORTED, /* elevator knows about this request */
@@ -172,6 +174,7 @@ enum rq_flag_bits {
#define REQ_UNPLUG (1 << __REQ_UNPLUG)
#define REQ_RAHEAD (1 << __REQ_RAHEAD)
+#define REQ_THROTTLED (1 << __REQ_THROTTLED)
#define REQ_SORTED (1 << __REQ_SORTED)
#define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 2c54906..66bca1a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -367,6 +367,11 @@ struct request_queue
#if defined(CONFIG_BLK_DEV_BSG)
struct bsg_class_device bsg_dev;
#endif
+
+#ifdef CONFIG_BLK_DEV_THROTTLING
+ /* Throttle data */
+ struct throtl_data *td;
+#endif
};
#define QUEUE_FLAG_CLUSTER 0 /* cluster several segments into 1 */
@@ -1127,6 +1132,7 @@ static inline void put_dev_sector(Sector p)
struct work_struct;
int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
+int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
#ifdef CONFIG_BLK_CGROUP
/*
@@ -1170,6 +1176,24 @@ static inline uint64_t rq_io_start_time_ns(struct request *req)
}
#endif
+#ifdef CONFIG_BLK_DEV_THROTTLING
+extern int blk_throtl_init(struct request_queue *q);
+extern void blk_throtl_exit(struct request_queue *q);
+extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
+extern void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay);
+extern void throtl_shutdown_timer_wq(struct request_queue *q);
+#else /* CONFIG_BLK_DEV_THROTTLING */
+static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
+{
+ return 0;
+}
+
+static inline int blk_throtl_init(struct request_queue *q) { return 0; }
+static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
+static inline void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay) {}
+static inline void throtl_shutdown_timer_wq(struct request_queue *q) {}
+#endif /* CONFIG_BLK_DEV_THROTTLING */
+
#define MODULE_ALIAS_BLOCKDEV(major,minor) \
MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
diff --git a/init/Kconfig b/init/Kconfig
index 2de5b1c..950ba26 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -634,11 +634,14 @@ config BLK_CGROUP
Currently, CFQ IO scheduler uses it to recognize task groups and
control disk bandwidth allocation (proportional time slice allocation)
- to such task groups.
+ to such task groups. It is also used by bio throttling logic in
+ block layer to implement upper limit in IO rates on a device.
This option only enables generic Block IO controller infrastructure.
- One needs to also enable actual IO controlling logic in CFQ for it
- to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).
+ One needs to also enable actual IO controlling logic/policy. For
+ enabling proportional weight division of disk bandwidth in CFQ seti
+ CONFIG_CFQ_GROUP_IOSCHED=y and for enabling throttling policy set
+ CONFIG_BLK_THROTTLE=y.
See Documentation/cgroups/blkio-controller.txt for more information.
--
1.7.2.3
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 5/7] blk-cgroup: cgroup changes for IOPS limit support
2010-09-15 21:06 [RFC PATCH] Block device bio throttling support [V3] Vivek Goyal
` (3 preceding siblings ...)
2010-09-15 21:06 ` [PATCH 4/7] blkio: Core implementation of throttle policy Vivek Goyal
@ 2010-09-15 21:06 ` Vivek Goyal
2010-09-15 21:06 ` [PATCH 6/7] blkio: Implementation of IOPS limit logic Vivek Goyal
` (3 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Vivek Goyal @ 2010-09-15 21:06 UTC (permalink / raw)
To: linux-kernel, axboe; +Cc: nauman, dpshah, guijianfeng, vgoyal
o cgroup changes for IOPS throttling rules.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-cgroup.c | 139 +++++++++++++++++++++++++++++++++++++++++++++------
block/blk-cgroup.h | 13 +++++
2 files changed, 135 insertions(+), 17 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 32b5920..a964a22 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -149,6 +149,27 @@ static inline void blkio_update_group_bps(struct blkio_group *blkg, u64 bps,
}
}
+static inline void blkio_update_group_iops(struct blkio_group *blkg,
+ unsigned int iops, int fileid)
+{
+ struct blkio_policy_type *blkiop;
+
+ list_for_each_entry(blkiop, &blkio_list, list) {
+
+ /* If this policy does not own the blkg, do not send updates */
+ if (blkiop->plid != blkg->plid)
+ continue;
+
+ if (fileid == BLKIO_THROTL_read_iops_device
+ && blkiop->ops.blkio_update_group_read_iops_fn)
+ blkiop->ops.blkio_update_group_read_iops_fn(blkg, iops);
+
+ if (fileid == BLKIO_THROTL_write_iops_device
+ && blkiop->ops.blkio_update_group_write_iops_fn)
+ blkiop->ops.blkio_update_group_write_iops_fn(blkg,iops);
+ }
+}
+
/*
* Add to the appropriate stat variable depending on the request type.
* This should be called with the blkg->stats_lock held.
@@ -630,7 +651,7 @@ static int blkio_policy_parse_and_set(char *buf,
{
char *s[4], *p, *major_s = NULL, *minor_s = NULL;
int ret;
- unsigned long major, minor, temp;
+ unsigned long major, minor, temp, iops;
int i = 0;
dev_t dev;
u64 bps;
@@ -692,13 +713,28 @@ static int blkio_policy_parse_and_set(char *buf,
newpn->val.weight = temp;
break;
case BLKIO_POLICY_THROTL:
- ret = strict_strtoull(s[1], 10, &bps);
- if (ret)
- return -EINVAL;
+ switch(fileid) {
+ case BLKIO_THROTL_read_bps_device:
+ case BLKIO_THROTL_write_bps_device:
+ ret = strict_strtoull(s[1], 10, &bps);
+ if (ret)
+ return -EINVAL;
- newpn->plid = plid;
- newpn->fileid = fileid;
- newpn->val.bps = bps;
+ newpn->plid = plid;
+ newpn->fileid = fileid;
+ newpn->val.bps = bps;
+ break;
+ case BLKIO_THROTL_read_iops_device:
+ case BLKIO_THROTL_write_iops_device:
+ ret = strict_strtoul(s[1], 10, &iops);
+ if (ret)
+ return -EINVAL;
+
+ newpn->plid = plid;
+ newpn->fileid = fileid;
+ newpn->val.iops = iops;
+ break;
+ }
break;
default:
BUG();
@@ -744,6 +780,29 @@ uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev)
return -1;
}
+unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev)
+{
+ struct blkio_policy_node *pn;
+
+ pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_read_iops_device);
+ if (pn)
+ return pn->val.iops;
+ else
+ return -1;
+}
+
+unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev)
+{
+ struct blkio_policy_node *pn;
+ pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_write_iops_device);
+ if (pn)
+ return pn->val.iops;
+ else
+ return -1;
+}
+
/* Checks whether user asked for deleting a policy rule */
static bool blkio_delete_rule_command(struct blkio_policy_node *pn)
{
@@ -753,8 +812,17 @@ static bool blkio_delete_rule_command(struct blkio_policy_node *pn)
return 1;
break;
case BLKIO_POLICY_THROTL:
- if (pn->val.bps == 0)
- return 1;
+ switch(pn->fileid) {
+ case BLKIO_THROTL_read_bps_device:
+ case BLKIO_THROTL_write_bps_device:
+ if (pn->val.bps == 0)
+ return 1;
+ break;
+ case BLKIO_THROTL_read_iops_device:
+ case BLKIO_THROTL_write_iops_device:
+ if (pn->val.iops == 0)
+ return 1;
+ }
break;
default:
BUG();
@@ -771,7 +839,15 @@ static void blkio_update_policy_rule(struct blkio_policy_node *oldpn,
oldpn->val.weight = newpn->val.weight;
break;
case BLKIO_POLICY_THROTL:
- oldpn->val.bps = newpn->val.bps;
+ switch(newpn->fileid) {
+ case BLKIO_THROTL_read_bps_device:
+ case BLKIO_THROTL_write_bps_device:
+ oldpn->val.bps = newpn->val.bps;
+ break;
+ case BLKIO_THROTL_read_iops_device:
+ case BLKIO_THROTL_write_iops_device:
+ oldpn->val.iops = newpn->val.iops;
+ }
break;
default:
BUG();
@@ -785,7 +861,7 @@ static void blkio_update_policy_rule(struct blkio_policy_node *oldpn,
static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg,
struct blkio_group *blkg, struct blkio_policy_node *pn)
{
- unsigned int weight;
+ unsigned int weight, iops;
u64 bps;
switch(pn->plid) {
@@ -801,6 +877,11 @@ static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg,
bps = pn->val.bps ? pn->val.bps : (-1);
blkio_update_group_bps(blkg, bps, pn->fileid);
break;
+ case BLKIO_THROTL_read_iops_device:
+ case BLKIO_THROTL_write_iops_device:
+ iops = pn->val.iops ? pn->val.iops : (-1);
+ blkio_update_group_iops(blkg, iops, pn->fileid);
+ break;
}
break;
default:
@@ -900,14 +981,18 @@ blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn)
MINOR(pn->dev), pn->val.weight);
break;
case BLKIO_POLICY_THROTL:
- if (pn->fileid == BLKIO_THROTL_read_bps_device)
+ switch(pn->fileid) {
+ case BLKIO_THROTL_read_bps_device:
+ case BLKIO_THROTL_write_bps_device:
seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev),
MINOR(pn->dev), pn->val.bps);
- else if (pn->fileid == BLKIO_THROTL_write_bps_device)
- seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev),
- MINOR(pn->dev), pn->val.bps);
- else
- BUG();
+ break;
+ case BLKIO_THROTL_read_iops_device:
+ case BLKIO_THROTL_write_iops_device:
+ seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
+ MINOR(pn->dev), pn->val.iops);
+ break;
+ }
break;
default:
BUG();
@@ -954,6 +1039,8 @@ static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft,
switch(name){
case BLKIO_THROTL_read_bps_device:
case BLKIO_THROTL_write_bps_device:
+ case BLKIO_THROTL_read_iops_device:
+ case BLKIO_THROTL_write_iops_device:
blkio_read_policy_node_files(cft, blkcg, m);
return 0;
default:
@@ -1171,6 +1258,24 @@ struct cftype blkio_files[] = {
.write_string = blkiocg_file_write,
.max_write_len = 256,
},
+
+ {
+ .name = "throttle.read_iops_device",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_read_iops_device),
+ .read_seq_string = blkiocg_file_read,
+ .write_string = blkiocg_file_write,
+ .max_write_len = 256,
+ },
+
+ {
+ .name = "throttle.write_iops_device",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_write_iops_device),
+ .read_seq_string = blkiocg_file_read,
+ .write_string = blkiocg_file_write,
+ .max_write_len = 256,
+ },
{
.name = "time",
.private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 1b73882..2070053 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -93,6 +93,8 @@ enum blkcg_file_name_prop {
enum blkcg_file_name_throtl {
BLKIO_THROTL_read_bps_device,
BLKIO_THROTL_write_bps_device,
+ BLKIO_THROTL_read_iops_device,
+ BLKIO_THROTL_write_iops_device,
BLKIO_THROTL_io_service_bytes,
BLKIO_THROTL_io_serviced,
};
@@ -168,6 +170,7 @@ struct blkio_policy_node {
* by file type "fileid".
*/
u64 bps;
+ unsigned int iops;
} val;
};
@@ -177,6 +180,10 @@ extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
dev_t dev);
extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
dev_t dev);
+extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
+ dev_t dev);
+extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
+ dev_t dev);
typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
@@ -185,12 +192,18 @@ typedef void (blkio_update_group_read_bps_fn) (struct blkio_group *blkg,
u64 read_bps);
typedef void (blkio_update_group_write_bps_fn) (struct blkio_group *blkg,
u64 write_bps);
+typedef void (blkio_update_group_read_iops_fn) (struct blkio_group *blkg,
+ unsigned int read_iops);
+typedef void (blkio_update_group_write_iops_fn) (struct blkio_group *blkg,
+ unsigned int write_iops);
struct blkio_policy_ops {
blkio_unlink_group_fn *blkio_unlink_group_fn;
blkio_update_group_weight_fn *blkio_update_group_weight_fn;
blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
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;
};
struct blkio_policy_type {
--
1.7.2.3
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 6/7] blkio: Implementation of IOPS limit logic
2010-09-15 21:06 [RFC PATCH] Block device bio throttling support [V3] Vivek Goyal
` (4 preceding siblings ...)
2010-09-15 21:06 ` [PATCH 5/7] blk-cgroup: cgroup changes for IOPS limit support Vivek Goyal
@ 2010-09-15 21:06 ` Vivek Goyal
2010-09-15 21:06 ` [PATCH 7/7] blkio: Documentation Update Vivek Goyal
` (2 subsequent siblings)
8 siblings, 0 replies; 11+ messages in thread
From: Vivek Goyal @ 2010-09-15 21:06 UTC (permalink / raw)
To: linux-kernel, axboe; +Cc: nauman, dpshah, guijianfeng, vgoyal
o core logic of implementing IOPS throttling.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-throttle.c | 164 ++++++++++++++++++++++++++++++++++++++-----------
1 files changed, 127 insertions(+), 37 deletions(-)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 966afc7..af53f37 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -59,8 +59,13 @@ struct throtl_grp {
/* bytes per second rate limits */
uint64_t bps[2];
+ /* IOPS limits */
+ unsigned int iops[2];
+
/* Number of bytes disptached in current slice */
uint64_t bytes_disp[2];
+ /* Number of bio's dispatched in current slice */
+ unsigned int io_disp[2];
/* When did we start a new slice */
unsigned long slice_start[2];
@@ -194,6 +199,8 @@ static struct throtl_grp * throtl_find_alloc_tg(struct throtl_data *td,
tg->bps[READ] = blkcg_get_read_bps(blkcg, tg->blkg.dev);
tg->bps[WRITE] = blkcg_get_write_bps(blkcg, tg->blkg.dev);
+ tg->iops[READ] = blkcg_get_read_iops(blkcg, tg->blkg.dev);
+ tg->iops[WRITE] = blkcg_get_write_iops(blkcg, tg->blkg.dev);
hlist_add_head(&tg->tg_node, &td->tg_list);
td->nr_undestroyed_grps++;
@@ -335,6 +342,7 @@ static inline void
throtl_start_new_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
{
tg->bytes_disp[rw] = 0;
+ tg->io_disp[rw] = 0;
tg->slice_start[rw] = jiffies;
tg->slice_end[rw] = jiffies + throtl_slice;
throtl_log_tg(td, tg, "[%c] new slice start=%lu end=%lu jiffies=%lu",
@@ -365,7 +373,7 @@ throtl_slice_used(struct throtl_data *td, struct throtl_grp *tg, bool rw)
static inline void
throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
{
- unsigned long nr_slices, bytes_trim, time_elapsed;
+ unsigned long nr_slices, bytes_trim, time_elapsed, io_trim;
BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw]));
@@ -385,8 +393,9 @@ throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
return;
bytes_trim = (tg->bps[rw] * throtl_slice * nr_slices)/HZ;
+ io_trim = (tg->iops[rw] * throtl_slice * nr_slices)/HZ;
- if (!bytes_trim)
+ if (!bytes_trim && !io_trim)
return;
if (tg->bytes_disp[rw] >= bytes_trim)
@@ -394,51 +403,62 @@ throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw)
else
tg->bytes_disp[rw] = 0;
+ if (tg->io_disp[rw] >= io_trim)
+ tg->io_disp[rw] -= io_trim;
+ else
+ tg->io_disp[rw] = 0;
+
tg->slice_start[rw] += nr_slices * throtl_slice;
- throtl_log_tg(td, tg, "[%c] trim slice nr=%lu bytes=%lu"
+ throtl_log_tg(td, tg, "[%c] trim slice nr=%lu bytes=%lu io=%lu"
" start=%lu end=%lu jiffies=%lu",
- rw == READ ? 'R' : 'W', nr_slices, bytes_trim,
+ rw == READ ? 'R' : 'W', nr_slices, bytes_trim, io_trim,
tg->slice_start[rw], tg->slice_end[rw], jiffies);
}
-/*
- * Returns whether one can dispatch a bio or not. Also returns approx number
- * of jiffies to wait before this bio is with-in IO rate and can be dispatched
- */
-static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg,
- struct bio *bio, unsigned long *wait)
+static bool tg_with_in_iops_limit(struct throtl_data *td, struct throtl_grp *tg,
+ struct bio *bio, unsigned long *wait)
{
bool rw = bio_data_dir(bio);
- u64 bytes_allowed, extra_bytes;
+ unsigned int io_allowed;
unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd;
- /*
- * Currently whole state machine of group depends on first bio
- * queued in the group bio list. So one should not be calling
- * this function with a different bio if there are other bios
- * queued.
- */
- BUG_ON(tg->nr_queued[rw] && bio != bio_list_peek(&tg->bio_lists[rw]));
+ jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw];
- /* If tg->bps = -1, then BW is unlimited */
- if (tg->bps[rw] == -1) {
+ /* Slice has just started. Consider one slice interval */
+ if (!jiffy_elapsed)
+ jiffy_elapsed_rnd = throtl_slice;
+
+ jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, throtl_slice);
+
+ io_allowed = (tg->iops[rw] * jiffies_to_msecs(jiffy_elapsed_rnd))
+ / MSEC_PER_SEC;
+
+ if (tg->io_disp[rw] + 1 <= io_allowed) {
if (wait)
*wait = 0;
return 1;
}
- /*
- * If previous slice expired, start a new one otherwise renew/extend
- * existing slice to make sure it is at least throtl_slice interval
- * long since now.
- */
- if (throtl_slice_used(td, tg, rw))
- throtl_start_new_slice(td, tg, rw);
- else {
- if (time_before(tg->slice_end[rw], jiffies + throtl_slice))
- throtl_extend_slice(td, tg, rw, jiffies + throtl_slice);
- }
+ /* Calc approx time to dispatch */
+ jiffy_wait = ((tg->io_disp[rw] + 1) * HZ)/tg->iops[rw] + 1;
+
+ if (jiffy_wait > jiffy_elapsed)
+ jiffy_wait = jiffy_wait - jiffy_elapsed;
+ else
+ jiffy_wait = 1;
+
+ if (wait)
+ *wait = jiffy_wait;
+ return 0;
+}
+
+static bool tg_with_in_bps_limit(struct throtl_data *td, struct throtl_grp *tg,
+ struct bio *bio, unsigned long *wait)
+{
+ bool rw = bio_data_dir(bio);
+ u64 bytes_allowed, extra_bytes;
+ unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd;
jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw];
@@ -469,12 +489,62 @@ static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg,
* up we did. Add that time also.
*/
jiffy_wait = jiffy_wait + (jiffy_elapsed_rnd - jiffy_elapsed);
-
if (wait)
*wait = jiffy_wait;
+ return 0;
+}
+
+/*
+ * Returns whether one can dispatch a bio or not. Also returns approx number
+ * of jiffies to wait before this bio is with-in IO rate and can be dispatched
+ */
+static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg,
+ struct bio *bio, unsigned long *wait)
+{
+ bool rw = bio_data_dir(bio);
+ unsigned long bps_wait = 0, iops_wait = 0, max_wait = 0;
+
+ /*
+ * Currently whole state machine of group depends on first bio
+ * queued in the group bio list. So one should not be calling
+ * this function with a different bio if there are other bios
+ * queued.
+ */
+ BUG_ON(tg->nr_queued[rw] && bio != bio_list_peek(&tg->bio_lists[rw]));
+
+ /* If tg->bps = -1, then BW is unlimited */
+ if (tg->bps[rw] == -1 && tg->iops[rw] == -1) {
+ if (wait)
+ *wait = 0;
+ return 1;
+ }
+
+ /*
+ * If previous slice expired, start a new one otherwise renew/extend
+ * existing slice to make sure it is at least throtl_slice interval
+ * long since now.
+ */
+ if (throtl_slice_used(td, tg, rw))
+ throtl_start_new_slice(td, tg, rw);
+ else {
+ if (time_before(tg->slice_end[rw], jiffies + throtl_slice))
+ throtl_extend_slice(td, tg, rw, jiffies + throtl_slice);
+ }
+
+ if (tg_with_in_bps_limit(td, tg, bio, &bps_wait)
+ && tg_with_in_iops_limit(td, tg, bio, &iops_wait)) {
+ if (wait)
+ *wait = 0;
+ return 1;
+ }
- if (time_before(tg->slice_end[rw], jiffies + jiffy_wait))
- throtl_extend_slice(td, tg, rw, jiffies + jiffy_wait);
+ max_wait = max(bps_wait, iops_wait);
+
+ if (wait)
+ *wait = max_wait;
+
+ if (time_before(tg->slice_end[rw], jiffies + max_wait))
+ throtl_extend_slice(td, tg, rw, jiffies + max_wait);
return 0;
}
@@ -486,13 +556,13 @@ static void throtl_charge_bio(struct throtl_grp *tg, struct bio *bio)
/* Charge the bio to the group */
tg->bytes_disp[rw] += bio->bi_size;
+ tg->io_disp[rw]++;
/*
* TODO: This will take blkg->stats_lock. Figure out a way
* to avoid this cost.
*/
blkiocg_update_dispatch_stats(&tg->blkg, bio->bi_size, rw, sync);
-
}
static void throtl_add_bio_tg(struct throtl_data *td, struct throtl_grp *tg,
@@ -763,6 +833,18 @@ static void throtl_update_blkio_group_write_bps (struct blkio_group *blkg,
tg_of_blkg(blkg)->bps[WRITE] = write_bps;
}
+static void throtl_update_blkio_group_read_iops (struct blkio_group *blkg,
+ unsigned int read_iops)
+{
+ tg_of_blkg(blkg)->iops[READ] = read_iops;
+}
+
+static void throtl_update_blkio_group_write_iops (struct blkio_group *blkg,
+ unsigned int write_iops)
+{
+ tg_of_blkg(blkg)->iops[WRITE] = write_iops;
+}
+
void throtl_shutdown_timer_wq(struct request_queue *q)
{
struct throtl_data *td = q->td;
@@ -777,7 +859,12 @@ static struct blkio_policy_type blkio_policy_throtl = {
throtl_update_blkio_group_read_bps,
.blkio_update_group_write_bps_fn =
throtl_update_blkio_group_write_bps,
+ .blkio_update_group_read_iops_fn =
+ throtl_update_blkio_group_read_iops,
+ .blkio_update_group_write_iops_fn =
+ throtl_update_blkio_group_write_iops,
},
+ .plid = BLKIO_POLICY_THROTL,
};
int blk_throtl_bio(struct request_queue *q, struct bio **biop)
@@ -811,9 +898,11 @@ int blk_throtl_bio(struct request_queue *q, struct bio **biop)
}
queue_bio:
- throtl_log_tg(td, tg, "[%c] bio. disp=%u sz=%u bps=%llu"
- " queued=%d/%d", rw == READ ? 'R' : 'W',
+ throtl_log_tg(td, tg, "[%c] bio. bdisp=%u sz=%u bps=%llu"
+ " iodisp=%u iops=%u queued=%d/%d",
+ rw == READ ? 'R' : 'W',
tg->bytes_disp[rw], bio->bi_size, tg->bps[rw],
+ tg->io_disp[rw], tg->iops[rw],
tg->nr_queued[READ], tg->nr_queued[WRITE]);
throtl_add_bio_tg(q->td, tg, bio);
@@ -850,6 +939,7 @@ int blk_throtl_init(struct request_queue *q)
/* Practically unlimited BW */
tg->bps[0] = tg->bps[1] = -1;
+ tg->iops[0] = tg->iops[1] = -1;
atomic_set(&tg->ref, 1);
INIT_DELAYED_WORK(&td->throtl_work, blk_throtl_work);
--
1.7.2.3
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 7/7] blkio: Documentation Update
2010-09-15 21:06 [RFC PATCH] Block device bio throttling support [V3] Vivek Goyal
` (5 preceding siblings ...)
2010-09-15 21:06 ` [PATCH 6/7] blkio: Implementation of IOPS limit logic Vivek Goyal
@ 2010-09-15 21:06 ` Vivek Goyal
2010-09-16 6:48 ` [RFC PATCH] Block device bio throttling support [V3] Jens Axboe
2010-09-16 7:10 ` Divyesh Shah
8 siblings, 0 replies; 11+ messages in thread
From: Vivek Goyal @ 2010-09-15 21:06 UTC (permalink / raw)
To: linux-kernel, axboe; +Cc: nauman, dpshah, guijianfeng, vgoyal
o Documentation update
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
Documentation/cgroups/blkio-controller.txt | 106 +++++++++++++++++++++++++++-
1 files changed, 103 insertions(+), 3 deletions(-)
diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt
index 6919d62..33df4a4 100644
--- a/Documentation/cgroups/blkio-controller.txt
+++ b/Documentation/cgroups/blkio-controller.txt
@@ -8,12 +8,17 @@ both at leaf nodes as well as at intermediate nodes in a storage hierarchy.
Plan is to use the same cgroup based management interface for blkio controller
and based on user options switch IO policies in the background.
-In the first phase, this patchset implements proportional weight time based
-division of disk policy. It is implemented in CFQ. Hence this policy takes
-effect only on leaf nodes when CFQ is being used.
+Currently two IO control policies are implemented. First one is proportional
+weight time based division of disk policy. It is implemented in CFQ. Hence
+this policy takes effect only on leaf nodes when CFQ is being used. The second
+one is throttling policy which can be used to specify upper IO rate limits
+on devices. This policy is implemented in generic block layer and can be
+used on leaf nodes as well as higher level logical devices like device mapper.
HOWTO
=====
+Proportional Weight division of bandwidth
+-----------------------------------------
You can do a very simple testing of running two dd threads in two different
cgroups. Here is what you can do.
@@ -55,6 +60,35 @@ cgroups. Here is what you can do.
group dispatched to the disk. We provide fairness in terms of disk time, so
ideally io.disk_time of cgroups should be in proportion to the weight.
+Throttling/Upper Limit policy
+-----------------------------
+- Enable Block IO controller
+ CONFIG_BLK_CGROUP=y
+
+- Enable throttling in block layer
+ CONFIG_BLK_DEV_THROTTLING=y
+
+- Mount blkio controller
+ mount -t cgroup -o blkio none /cgroup/blkio
+
+- Specify a bandwidth rate on particular device for root group. The format
+ for policy is "<major>:<minor> <byes_per_second>".
+
+ echo "8:16 1048576" > /cgroup/blkio/blkio.read_bps_device
+
+ Above will put a limit of 1MB/second on reads happening for root group
+ on device having major/minor number 8:16.
+
+- Run dd to read a file and see if rate is throttled to 1MB/s or not.
+
+ # dd if=/mnt/common/zerofile of=/dev/null bs=4K count=1024
+ # iflag=direct
+ 1024+0 records in
+ 1024+0 records out
+ 4194304 bytes (4.2 MB) copied, 4.0001 s, 1.0 MB/s
+
+ Limits for writes can be put using blkio.write_bps_device file.
+
Various user visible config options
===================================
CONFIG_BLK_CGROUP
@@ -68,8 +102,13 @@ CONFIG_CFQ_GROUP_IOSCHED
- Enables group scheduling in CFQ. Currently only 1 level of group
creation is allowed.
+CONFIG_BLK_DEV_THROTTLING
+ - Enable block device throttling support in block layer.
+
Details of cgroup files
=======================
+Proportional weight policy files
+--------------------------------
- blkio.weight
- Specifies per cgroup weight. This is default weight of the group
on all the devices until and unless overridden by per device rule.
@@ -210,6 +249,67 @@ Details of cgroup files
and minor number of the device and third field specifies the number
of times a group was dequeued from a particular device.
+Throttling/Upper limit policy files
+-----------------------------------
+- blkio.throttle.read_bps_device
+ - Specifies upper limit on READ rate from the device. IO rate is
+ specified in bytes per second. Rules are per deivce. Following is
+ the format.
+
+ echo "<major>:<minor> <rate_bytes_per_second>" > /cgrp/blkio.read_bps_device
+
+- blkio.throttle.write_bps_device
+ - Specifies upper limit on WRITE rate to the device. IO rate is
+ specified in bytes per second. Rules are per deivce. Following is
+ the format.
+
+ echo "<major>:<minor> <rate_bytes_per_second>" > /cgrp/blkio.write_bps_device
+
+- blkio.throttle.read_iops_device
+ - Specifies upper limit on READ rate from the device. IO rate is
+ specified in IO per second. Rules are per deivce. Following is
+ the format.
+
+ echo "<major>:<minor> <rate_io_per_second>" > /cgrp/blkio.read_iops_device
+
+- blkio.throttle.write_iops_device
+ - Specifies upper limit on WRITE rate to the device. IO rate is
+ specified in io per second. Rules are per deivce. Following is
+ the format.
+
+ echo "<major>:<minor> <rate_io_per_second>" > /cgrp/blkio.write_iops_device
+
+Note: If both BW and IOPS rules are specified for a device, then IO is
+ subjectd to both the constraints.
+
+- blkio.throttle.io_serviced
+ - Number of IOs (bio) completed to/from the disk by the group (as
+ seen by throttling policy). These are further divided by the type
+ of operation - read or write, sync or async. First two fields specify
+ the major and minor number of the device, third field specifies the
+ operation type and the fourth field specifies the number of IOs.
+
+ blkio.io_serviced does accounting as seen by CFQ and counts are in
+ number of requests (struct request). On the other hand,
+ blkio.throttle.io_serviced counts number of IO in terms of number
+ of bios as seen by throttling policy. These bios can later be
+ merged by elevator and total number of requests completed can be
+ lesser.
+
+- blkio.throttle.io_service_bytes
+ - Number of bytes transferred to/from the disk by the group. These
+ are further divided by the type of operation - read or write, sync
+ or async. First two fields specify the major and minor number of the
+ device, third field specifies the operation type and the fourth field
+ specifies the number of bytes.
+
+ These numbers should roughly be same as blkio.io_service_bytes as
+ updated by CFQ. The difference between two is that
+ blkio.io_service_bytes will not be updated if CFQ is not operating
+ on request queue.
+
+Common files among various policies
+-----------------------------------
- blkio.reset_stats
- Writing an int to this file will result in resetting all the stats
for that cgroup.
--
1.7.2.3
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [RFC PATCH] Block device bio throttling support [V3]
2010-09-15 21:06 [RFC PATCH] Block device bio throttling support [V3] Vivek Goyal
` (6 preceding siblings ...)
2010-09-15 21:06 ` [PATCH 7/7] blkio: Documentation Update Vivek Goyal
@ 2010-09-16 6:48 ` Jens Axboe
2010-09-16 15:39 ` Vivek Goyal
2010-09-16 7:10 ` Divyesh Shah
8 siblings, 1 reply; 11+ messages in thread
From: Jens Axboe @ 2010-09-16 6:48 UTC (permalink / raw)
To: Vivek Goyal; +Cc: linux-kernel, nauman, dpshah, guijianfeng
On 2010-09-15 23:06, Vivek Goyal wrote:
> Hi,
>
> This is V3 of the bio throttling patches. Following are changes since V2.
>
> - Added the support for throttling in terms of IOPS (READ/WRITE). If one
> specifies both bandwidth as well as IOPS rules on a device then IO is
> subjected to both the rules.
>
> - Did few bug fixes.
>
> - Did some cleanups in blk-cgroup code.
Vivek, I have merged these patches now to get some exposure and
testing before .37 gets too close.
--
Jens Axboe
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [RFC PATCH] Block device bio throttling support [V3]
2010-09-16 6:48 ` [RFC PATCH] Block device bio throttling support [V3] Jens Axboe
@ 2010-09-16 15:39 ` Vivek Goyal
0 siblings, 0 replies; 11+ messages in thread
From: Vivek Goyal @ 2010-09-16 15:39 UTC (permalink / raw)
To: Jens Axboe; +Cc: linux-kernel, nauman, dpshah, guijianfeng
On Thu, Sep 16, 2010 at 08:48:05AM +0200, Jens Axboe wrote:
> On 2010-09-15 23:06, Vivek Goyal wrote:
> > Hi,
> >
> > This is V3 of the bio throttling patches. Following are changes since V2.
> >
> > - Added the support for throttling in terms of IOPS (READ/WRITE). If one
> > specifies both bandwidth as well as IOPS rules on a device then IO is
> > subjected to both the rules.
> >
> > - Did few bug fixes.
> >
> > - Did some cleanups in blk-cgroup code.
>
> Vivek, I have merged these patches now to get some exposure and
> testing before .37 gets too close.
Thanks Jens.
Few things I had in mind.
- I have not implemented any barrier or ordering mechanism in throttling
logic. I am assuming that all the barrier work to get rid of ordering
semantics will also go in 2.6.37 and then we really should not need
to implement any ordering in throttling logic. So it should be a non-issue.
- All throttling logic can simply be disabled by setting
CONFIG_BLK_DEV_THROTTLING=n. It is already disabled by default. I will
do some performance testing on faster storage to see what is the cost
if CONFIG_BLK_DEV_THROTTLING=y and bandwidth is unlimited.
- I am still trying to figure out what to do about max number of bios which
can be throttled and pending and how to gel it well with request queue
congestion logic.
Thanks
Vivek
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [RFC PATCH] Block device bio throttling support [V3]
2010-09-15 21:06 [RFC PATCH] Block device bio throttling support [V3] Vivek Goyal
` (7 preceding siblings ...)
2010-09-16 6:48 ` [RFC PATCH] Block device bio throttling support [V3] Jens Axboe
@ 2010-09-16 7:10 ` Divyesh Shah
8 siblings, 0 replies; 11+ messages in thread
From: Divyesh Shah @ 2010-09-16 7:10 UTC (permalink / raw)
To: Vivek Goyal; +Cc: linux-kernel, axboe, nauman, guijianfeng
Hi Vivek,
I took a look at the patches and overall they look good to me.
I'll need to take a closer look at the main throttling patch and the
put on a queue when throttled behavior. Will post comments if any in a
day or so.
-Divyesh
On Wed, Sep 15, 2010 at 2:06 PM, Vivek Goyal <vgoyal@redhat.com> wrote:
>
> Hi,
>
> This is V3 of the bio throttling patches. Following are changes since V2.
>
> - Added the support for throttling in terms of IOPS (READ/WRITE). If one
> specifies both bandwidth as well as IOPS rules on a device then IO is
> subjected to both the rules.
>
> - Did few bug fixes.
>
> - Did some cleanups in blk-cgroup code.
>
> Previous version of patches are available here.
>
> [V2] http://lkml.org/lkml/2010/9/7/386
> [V1] http://lkml.org/lkml/2010/9/1/251
>
> Overview
> ========
> Currently CFQ provides the weight based proportional division of bandwidth.
> People also have been looking at extending block IO controller to provide
> throttling/max bandwidth control.
>
> I have started to write the support for throttling in block layer on
> request queue so that it can be used both for higher level logical
> devices as well as leaf nodes. This patch is still work in progress but
> I wanted to post it for early feedback.
>
> Basically currently I have hooked into __generic_make_request() function to
> check which cgroup bio belongs to and if it is exceeding the specified
> BW rate. If no, thread can continue to dispatch bio as it is otherwise
> bio is queued internally and dispatched later with the help of a worker
> thread.
>
> One can do bio throttling in terms of bandwidth(bytes per second) or in
> terms of IO per second or both. Both BW and IOPS rules can be put either
> on READ or WRITE flow.
>
> Throttling logic is independent of IO scheduler hence can be used with any
> IO scheduler operating. It also can be activated and used on any block
> device/request queue, in the stack.
>
> HOWTO
> =====
> - Make sure CONFIG_BLK_CGROUP=y and CONFIG_BLK_DEV_THROTTLING=y.
>
> - Mount blkio controller
> mount -t cgroup -o blkio none /cgroup/blkio
>
> - Specify a bandwidth rate on particular device for root group. The format
> for policy is "<major>:<minor> <byes_per_second>".
>
> echo "8:16 1048576" > /cgroup/blkio/blkio.throttle.read_bps_device
>
> Above will put a limit of 1MB/second on reads happening for root group
> on device having major/minor number 8:16.
>
> - Run dd to read a file and see if rate is throttled to 1MB/s or not.
>
> # dd if=/mnt/common/zerofile of=/dev/null bs=4K count=1024 iflag=direct
> 1024+0 records in
> 1024+0 records out
> 4194304 bytes (4.2 MB) copied, 4.0001 s, 1.0 MB/s
>
> Note:
> -----
> - Limits for writes can be put using blkio.throttle.write_bps_device file.
> - Limits for IOPS rules can be put using following files.
>
> blkio.throttle.read_iops_device
> blkio.throttle.write_iops_device
>
> Fore more info refer to Documentation/cgroup/blkio-controller.txt
>
> Open Issues
> ===========
> - Do we need to provide additional queue congestion semantics as we are
> throttling and queuing bios at request queue and probably we don't want
> a user space application to consume all the memory allocating bios
> and bombarding request queue with those bios.
>
> TODO
> ====
> - Testing, bug fixes.
>
> Any feedback is welcome.
>
> Overall diffstat.
>
> Documentation/cgroups/blkio-controller.txt | 106 +++-
> block/Kconfig | 12 +
> block/Makefile | 1 +
> block/blk-cgroup.c | 786 ++++++++++++++++++-----
> block/blk-cgroup.h | 79 +++-
> block/blk-core.c | 24 +
> block/blk-throttle.c | 999 ++++++++++++++++++++++++++++
> block/cfq-iosched.c | 1 +
> block/cfq.h | 2 +-
> include/linux/blk_types.h | 3 +
> include/linux/blkdev.h | 24 +
> init/Kconfig | 9 +-
> 12 files changed, 1881 insertions(+), 165 deletions(-)
>
> Thanks
> Vivek
>
^ permalink raw reply [flat|nested] 11+ messages in thread