From 34d0f179d6dd711d3fc13c0820a456c59aae8048 Mon Sep 17 00:00:00 2001 From: Gui Jianfeng Date: Tue, 13 Apr 2010 16:05:49 +0800 Subject: [PATCH] io-controller: Add a new interface "weight_device" for IO-Controller Currently, IO Controller makes use of blkio.weight to assign weight for all devices. Here a new user interface "blkio.weight_device" is introduced to assign different weights for different devices. blkio.weight becomes the default value for devices which are not configured by "blkio.weight_device" You can use the following format to assigned specific weight for a given device: #echo "major:minor weight" > blkio.weight_device major:minor represents device number. And you can remove weight for a given device as following: #echo "major:minor 0" > blkio.weight_device V1->V2 changes: - use user interface "weight_device" instead of "policy" suggested by Vivek - rename some struct suggested by Vivek - rebase to 2.6-block "for-linus" branch - remove an useless list_empty check pointed out by Li Zefan - some trivial typo fix V2->V3 changes: - Move policy_*_node() functions up to get rid of forward declarations - rename related functions by adding prefix "blkio_" Signed-off-by: Gui Jianfeng Acked-by: Vivek Goyal Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 236 ++++++++++++++++++++++++++++++++++++++++++++++++++++ block/blk-cgroup.h | 10 +++ block/cfq-iosched.c | 2 +- 3 files changed, 247 insertions(+), 1 deletion(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 1ecff7a..649b05d 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -17,6 +17,7 @@ #include #include #include "blk-cgroup.h" +#include #define MAX_KEY_LEN 100 @@ -51,6 +52,32 @@ struct cgroup_subsys blkio_subsys = { }; EXPORT_SYMBOL_GPL(blkio_subsys); +static inline void blkio_policy_insert_node(struct blkio_cgroup *blkcg, + struct blkio_policy_node *pn) +{ + list_add(&pn->node, &blkcg->policy_list); +} + +/* Must be called with blkcg->lock held */ +static inline void blkio_policy_delete_node(struct blkio_policy_node *pn) +{ + list_del(&pn->node); +} + +/* Must be called with blkcg->lock held */ +static struct blkio_policy_node * +blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev) +{ + struct blkio_policy_node *pn; + + list_for_each_entry(pn, &blkcg->policy_list, node) { + if (pn->dev == dev) + return pn; + } + + return NULL; +} + struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id), @@ -398,6 +425,7 @@ blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val) 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; @@ -406,7 +434,13 @@ blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val) 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); @@ -611,8 +645,203 @@ void blkiocg_update_dequeue_stats(struct blkio_group *blkg, EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats); #endif +static int blkio_check_dev_num(dev_t dev) +{ + int part = 0; + struct gendisk *disk; + + disk = get_gendisk(dev, &part); + if (!disk || part) + return -ENODEV; + + return 0; +} + +static int blkio_policy_parse_and_set(char *buf, + struct blkio_policy_node *newpn) +{ + char *s[4], *p, *major_s = NULL, *minor_s = NULL; + int ret; + unsigned long major, minor, temp; + int i = 0; + dev_t dev; + + memset(s, 0, sizeof(s)); + + while ((p = strsep(&buf, " ")) != NULL) { + if (!*p) + continue; + + s[i++] = p; + + /* Prevent from inputing too many things */ + if (i == 3) + break; + } + + if (i != 2) + return -EINVAL; + + p = strsep(&s[0], ":"); + if (p != NULL) + major_s = p; + else + return -EINVAL; + + minor_s = s[0]; + if (!minor_s) + return -EINVAL; + + ret = strict_strtoul(major_s, 10, &major); + if (ret) + return -EINVAL; + + ret = strict_strtoul(minor_s, 10, &minor); + if (ret) + return -EINVAL; + + dev = MKDEV(major, minor); + + ret = blkio_check_dev_num(dev); + if (ret) + return ret; + + newpn->dev = dev; + + 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; + + newpn->weight = temp; + + return 0; +} + +unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg, + dev_t dev) +{ + struct blkio_policy_node *pn; + + pn = blkio_policy_search_node(blkcg, dev); + if (pn) + return pn->weight; + else + return blkcg->weight; +} +EXPORT_SYMBOL_GPL(blkcg_get_weight); + + +static int blkiocg_weight_device_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; + + buf = kstrdup(buffer, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + newpn = kzalloc(sizeof(*newpn), GFP_KERNEL); + if (!newpn) { + ret = -ENOMEM; + goto free_buf; + } + + ret = blkio_policy_parse_and_set(buf, newpn); + if (ret) + goto free_newpn; + + blkcg = cgroup_to_blkio_cgroup(cgrp); + + spin_lock_irq(&blkcg->lock); + + pn = blkio_policy_search_node(blkcg, newpn->dev); + if (!pn) { + if (newpn->weight != 0) { + blkio_policy_insert_node(blkcg, newpn); + keep_newpn = 1; + } + spin_unlock_irq(&blkcg->lock); + goto update_io_group; + } + + if (newpn->weight == 0) { + /* weight == 0 means deleteing a specific weight */ + blkio_policy_delete_node(pn); + spin_unlock_irq(&blkcg->lock); + goto update_io_group; + } + spin_unlock_irq(&blkcg->lock); + + pn->weight = newpn->weight; + +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); + +free_newpn: + if (!keep_newpn) + kfree(newpn); +free_buf: + kfree(buf); + return ret; +} + +static int blkiocg_weight_device_read(struct cgroup *cgrp, struct cftype *cft, + struct seq_file *m) +{ + 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)) + goto out; + + 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); + } + spin_unlock_irq(&blkcg->lock); + +out: + return 0; +} + struct cftype blkio_files[] = { { + .name = "weight_device", + .read_seq_string = blkiocg_weight_device_read, + .write_string = blkiocg_weight_device_write, + .max_write_len = 256, + }, + { .name = "weight", .read_u64 = blkiocg_weight_read, .write_u64 = blkiocg_weight_write, @@ -690,6 +919,7 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) struct blkio_group *blkg; void *key; struct blkio_policy_type *blkiop; + struct blkio_policy_node *pn, *pntmp; rcu_read_lock(); remove_entry: @@ -720,7 +950,12 @@ remove_entry: blkiop->ops.blkio_unlink_group_fn(key, blkg); spin_unlock(&blkio_list_lock); goto remove_entry; + done: + list_for_each_entry_safe(pn, pntmp, &blkcg->policy_list, node) { + blkio_policy_delete_node(pn); + kfree(pn); + } free_css_id(&blkio_subsys, &blkcg->css); rcu_read_unlock(); if (blkcg != &blkio_root_cgroup) @@ -751,6 +986,7 @@ done: spin_lock_init(&blkcg->lock); INIT_HLIST_HEAD(&blkcg->blkg_list); + INIT_LIST_HEAD(&blkcg->policy_list); return &blkcg->css; } diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index bfce085..3c27bdf 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -70,6 +70,7 @@ struct blkio_cgroup { unsigned int weight; spinlock_t lock; struct hlist_head blkg_list; + struct list_head policy_list; /* list of blkio_policy_node */ }; struct blkio_group_stats { @@ -119,6 +120,15 @@ struct blkio_group { struct blkio_group_stats stats; }; +struct blkio_policy_node { + struct list_head node; + dev_t dev; + unsigned int weight; +}; + +extern unsigned int blkcg_get_weight(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); diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index b6e095c..91af2f2 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -952,7 +952,6 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create) if (!cfqg) goto done; - cfqg->weight = blkcg->weight; for_each_cfqg_st(cfqg, i, j, st) *st = CFQ_RB_ROOT; RB_CLEAR_NODE(&cfqg->rb_node); @@ -970,6 +969,7 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create) sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd, MKDEV(major, minor)); + cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev); /* Add group on cfqd list */ hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list); -- 2.7.4