On Wed, May 13, 2009 at 10:00:21AM +0800, Gui Jianfeng wrote: > Hi Vivek, > > This patch enables per-cgroup per-device weight and ioprio_class handling. > A new cgroup interface "policy" is introduced. You can make use of this > file to configure weight and ioprio_class for each device in a given cgroup. > The original "weight" and "ioprio_class" files are still available. If you > don't do special configuration for a particular device, "weight" and > "ioprio_class" are used as default values in this device. > > You can use the following format to play with the new interface. > #echo DEV:weight:ioprio_class > /patch/to/cgroup/policy > weight=0 means removing the policy for DEV. >
Thanks for the patch Gui. I will test it out and let you know how does it go. Thanks Vivek > Examples: > Configure weight=300 ioprio_class=2 on /dev/hdb in this cgroup > # echo /dev/hdb:300:2 > io.policy > # cat io.policy > dev weight class > /dev/hdb 300 2 > > Configure weight=500 ioprio_class=1 on /dev/hda in this cgroup > # echo /dev/hda:500:1 > io.policy > # cat io.policy > dev weight class > /dev/hda 500 1 > /dev/hdb 300 2 > > Remove the policy for /dev/hda in this cgroup > # echo /dev/hda:0:1 > io.policy > # cat io.policy > dev weight class > /dev/hdb 300 2 > > Signed-off-by: Gui Jianfeng <[email protected]> > --- > block/elevator-fq.c | 239 +++++++++++++++++++++++++++++++++++++++++++++++++- > block/elevator-fq.h | 11 +++ > 2 files changed, 245 insertions(+), 5 deletions(-) > > diff --git a/block/elevator-fq.c b/block/elevator-fq.c > index 69435ab..7c95d55 100644 > --- a/block/elevator-fq.c > +++ b/block/elevator-fq.c > @@ -12,6 +12,9 @@ > #include "elevator-fq.h" > #include <linux/blktrace_api.h> > #include <linux/biotrack.h> > +#include <linux/seq_file.h> > +#include <linux/genhd.h> > + > > /* Values taken from cfq */ > const int elv_slice_sync = HZ / 10; > @@ -1045,12 +1048,30 @@ struct io_group *io_lookup_io_group_current(struct > request_queue *q) > } > EXPORT_SYMBOL(io_lookup_io_group_current); > > -void io_group_init_entity(struct io_cgroup *iocg, struct io_group *iog) > +static struct policy_node *policy_search_node(const struct io_cgroup *iocg, > + void *key); > + > +void io_group_init_entity(struct io_cgroup *iocg, struct io_group *iog, > + void *key) > { > struct io_entity *entity = &iog->entity; > + struct policy_node *pn; > + > + spin_lock_irq(&iocg->lock); > + pn = policy_search_node(iocg, key); > + if (pn) { > + entity->weight = pn->weight; > + entity->new_weight = pn->weight; > + entity->ioprio_class = pn->ioprio_class; > + entity->new_ioprio_class = pn->ioprio_class; > + } else { > + entity->weight = iocg->weight; > + entity->new_weight = iocg->weight; > + entity->ioprio_class = iocg->ioprio_class; > + entity->new_ioprio_class = iocg->ioprio_class; > + } > + spin_unlock_irq(&iocg->lock); > > - entity->weight = entity->new_weight = iocg->weight; > - entity->ioprio_class = entity->new_ioprio_class = iocg->ioprio_class; > entity->ioprio_changed = 1; > entity->my_sched_data = &iog->sched_data; > } > @@ -1263,7 +1284,7 @@ struct io_group *io_group_chain_alloc(struct > request_queue *q, void *key, > atomic_set(&iog->ref, 0); > iog->deleting = 0; > > - io_group_init_entity(iocg, iog); > + io_group_init_entity(iocg, iog, key); > iog->my_entity = &iog->entity; > #ifdef CONFIG_DEBUG_GROUP_IOSCHED > iog->iocg_id = css_id(&iocg->css); > @@ -1549,8 +1570,208 @@ struct io_group *io_alloc_root_group(struct > request_queue *q, > return iog; > } > > +static int io_cgroup_policy_read(struct cgroup *cgrp, struct cftype *cft, > + struct seq_file *m) > +{ > + struct io_cgroup *iocg; > + struct policy_node *pn; > + > + iocg = cgroup_to_io_cgroup(cgrp); > + > + if (list_empty(&iocg->list)) > + goto out; > + > + seq_printf(m, "dev weight class\n"); > + > + spin_lock_irq(&iocg->lock); > + list_for_each_entry(pn, &iocg->list, node) { > + seq_printf(m, "%s %lu %lu\n", pn->dev_name, > + pn->weight, pn->ioprio_class); > + } > + spin_unlock_irq(&iocg->lock); > +out: > + return 0; > +} > + > +static inline void policy_insert_node(struct io_cgroup *iocg, > + struct policy_node *pn) > +{ > + list_add(&pn->node, &iocg->list); > +} > + > +/* Must be called with iocg->lock held */ > +static inline void policy_delete_node(struct policy_node *pn) > +{ > + list_del(&pn->node); > +} > + > +/* Must be called with iocg->lock held */ > +static struct policy_node *policy_search_node(const struct io_cgroup *iocg, > + void *key) > +{ > + struct policy_node *pn; > + > + if (list_empty(&iocg->list)) > + return NULL; > + > + list_for_each_entry(pn, &iocg->list, node) { > + if (pn->key == key) > + return pn; > + } > + > + return NULL; > +} > + > +static void *devname_to_efqd(const char *buf) > +{ > + struct block_device *bdev; > + void *key = NULL; > + struct gendisk *disk; > + int part; > + > + bdev = lookup_bdev(buf); > + if (IS_ERR(bdev)) > + return NULL; > + > + disk = get_gendisk(bdev->bd_dev, &part); > + key = (void *)&disk->queue->elevator->efqd; > + bdput(bdev); > + > + return key; > +} > + > +static int policy_parse_and_set(char *buf, struct policy_node *newpn) > +{ > + char *s[3]; > + char *p; > + int ret; > + int i = 0; > + > + memset(s, 0, sizeof(s)); > + while (i < ARRAY_SIZE(s)) { > + p = strsep(&buf, ":"); > + if (!p) > + break; > + if (!*p) > + continue; > + s[i++] = p; > + } > + > + newpn->key = devname_to_efqd(s[0]); > + if (!newpn->key) > + return -EINVAL; > + > + strcpy(newpn->dev_name, s[0]); > + > + ret = strict_strtoul(s[1], 10, &newpn->weight); > + if (ret || newpn->weight > WEIGHT_MAX) > + return -EINVAL; > + > + ret = strict_strtoul(s[2], 10, &newpn->ioprio_class); > + if (ret || newpn->ioprio_class < IOPRIO_CLASS_RT || > + newpn->ioprio_class > IOPRIO_CLASS_IDLE) > + return -EINVAL; > + > + return 0; > +} > + > +static int io_cgroup_policy_write(struct cgroup *cgrp, struct cftype *cft, > + const char *buffer) > +{ > + struct io_cgroup *iocg; > + struct policy_node *newpn, *pn; > + char *buf; > + int ret = 0; > + int keep_newpn = 0; > + struct hlist_node *n; > + struct io_group *iog; > + > + buf = kstrdup(buffer, GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > + > + newpn = kzalloc(sizeof(*newpn), GFP_KERNEL); > + if (!newpn) { > + ret = -ENOMEM; > + goto free_buf; > + } > + > + ret = policy_parse_and_set(buf, newpn); > + if (ret) > + goto free_newpn; > + > + if (!cgroup_lock_live_group(cgrp)) { > + ret = -ENODEV; > + goto free_newpn; > + } > + > + iocg = cgroup_to_io_cgroup(cgrp); > + spin_lock_irq(&iocg->lock); > + > + pn = policy_search_node(iocg, newpn->key); > + if (!pn) { > + if (newpn->weight != 0) { > + policy_insert_node(iocg, newpn); > + keep_newpn = 1; > + } > + goto update_io_group; > + } > + > + if (newpn->weight == 0) { > + /* weight == 0 means deleteing a policy */ > + policy_delete_node(pn); > + goto update_io_group; > + } > + > + pn->weight = newpn->weight; > + pn->ioprio_class = newpn->ioprio_class; > + > +update_io_group: > + hlist_for_each_entry(iog, n, &iocg->group_data, group_node) { > + if (iog->key == newpn->key) { > + if (newpn->weight) { > + iog->entity.new_weight = newpn->weight; > + iog->entity.new_ioprio_class = > + newpn->ioprio_class; > + /* > + * iog weight and ioprio_class updating > + * actually happens if ioprio_changed is set. > + * So ensure ioprio_changed is not set until > + * new weight and new ioprio_class are updated. > + */ > + smp_wmb(); > + iog->entity.ioprio_changed = 1; > + } else { > + iog->entity.new_weight = iocg->weight; > + iog->entity.new_ioprio_class = > + iocg->ioprio_class; > + > + /* The same as above */ > + smp_wmb(); > + iog->entity.ioprio_changed = 1; > + } > + } > + } > + spin_unlock_irq(&iocg->lock); > + > + cgroup_unlock(); > + > +free_newpn: > + if (!keep_newpn) > + kfree(newpn); > +free_buf: > + kfree(buf); > + return ret; > +} > + > struct cftype bfqio_files[] = { > { > + .name = "policy", > + .read_seq_string = io_cgroup_policy_read, > + .write_string = io_cgroup_policy_write, > + .max_write_len = 256, > + }, > + { > .name = "weight", > .read_u64 = io_cgroup_weight_read, > .write_u64 = io_cgroup_weight_write, > @@ -1592,6 +1813,7 @@ struct cgroup_subsys_state *iocg_create(struct > cgroup_subsys *subsys, > INIT_HLIST_HEAD(&iocg->group_data); > iocg->weight = IO_DEFAULT_GRP_WEIGHT; > iocg->ioprio_class = IO_DEFAULT_GRP_CLASS; > + INIT_LIST_HEAD(&iocg->list); > > return &iocg->css; > } > @@ -1750,6 +1972,7 @@ void iocg_destroy(struct cgroup_subsys *subsys, struct > cgroup *cgroup) > unsigned long flags, flags1; > int queue_lock_held = 0; > struct elv_fq_data *efqd; > + struct policy_node *pn, *pntmp; > > /* > * io groups are linked in two lists. One list is maintained > @@ -1823,6 +2046,12 @@ locked: > BUG_ON(!hlist_empty(&iocg->group_data)); > > free_css_id(&io_subsys, &iocg->css); > + > + list_for_each_entry_safe(pn, pntmp, &iocg->list, node) { > + policy_delete_node(pn); > + kfree(pn); > + } > + > kfree(iocg); > } > > @@ -2137,7 +2366,7 @@ void elv_fq_unset_request_ioq(struct request_queue *q, > struct request *rq) > void bfq_init_entity(struct io_entity *entity, struct io_group *iog) > { > entity->ioprio = entity->new_ioprio; > - entity->weight = entity->new_weight; > + entity->weight = entity->new_weigh; > entity->ioprio_class = entity->new_ioprio_class; > entity->sched_data = &iog->sched_data; > } > diff --git a/block/elevator-fq.h b/block/elevator-fq.h > index db3a347..0407633 100644 > --- a/block/elevator-fq.h > +++ b/block/elevator-fq.h > @@ -253,6 +253,14 @@ struct io_group { > #endif > }; > > +struct policy_node { > + struct list_head node; > + char dev_name[32]; > + void *key; > + unsigned long weight; > + unsigned long ioprio_class; > +}; > + > /** > * struct bfqio_cgroup - bfq cgroup data structure. > * @css: subsystem state for bfq in the containing cgroup. > @@ -269,6 +277,9 @@ struct io_cgroup { > > unsigned long weight, ioprio_class; > > + /* list of policy_node */ > + struct list_head list; > + > spinlock_t lock; > struct hlist_head group_data; > }; > -- > 1.5.4.rc3 > > _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
