From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754034AbZIXT0k (ORCPT ); Thu, 24 Sep 2009 15:26:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754003AbZIXT0i (ORCPT ); Thu, 24 Sep 2009 15:26:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32294 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753011AbZIXT0c (ORCPT ); Thu, 24 Sep 2009 15:26:32 -0400 From: Vivek Goyal To: linux-kernel@vger.kernel.org, jens.axboe@oracle.com Cc: containers@lists.linux-foundation.org, dm-devel@redhat.com, nauman@google.com, dpshah@google.com, lizf@cn.fujitsu.com, mikew@google.com, fchecconi@gmail.com, paolo.valente@unimore.it, ryov@valinux.co.jp, fernando@oss.ntt.co.jp, s-uchida@ap.jp.nec.com, taka@valinux.co.jp, guijianfeng@cn.fujitsu.com, jmoyer@redhat.com, dhaval@linux.vnet.ibm.com, balbir@linux.vnet.ibm.com, righi.andrea@gmail.com, m-ikeda@ds.jp.nec.com, agk@redhat.com, vgoyal@redhat.com, akpm@linux-foundation.org, peterz@infradead.org, jmarchan@redhat.com, torvalds@linux-foundation.org, mingo@elte.hu, riel@redhat.com Subject: [PATCH 27/28] io-controller: Support per cgroup per device weights and io class Date: Thu, 24 Sep 2009 15:25:31 -0400 Message-Id: <1253820332-10246-28-git-send-email-vgoyal@redhat.com> In-Reply-To: <1253820332-10246-1-git-send-email-vgoyal@redhat.com> References: <1253820332-10246-1-git-send-email-vgoyal@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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_major:dev_minor weight ioprio_class > /patch/to/cgroup/policy weight=0 means removing the policy for device. Examples: Configure weight=300 ioprio_class=2 on /dev/hdb (8:16) in this cgroup # echo "8:16 300 2" > io.policy # cat io.policy dev weight class 8:16 300 2 Configure weight=500 ioprio_class=1 on /dev/hda (8:0) in this cgroup # echo "8:0 500 1" > io.policy # cat io.policy dev weight class 8:0 500 1 8:16 300 2 Remove the policy for /dev/hda in this cgroup # echo 8:0 0 1 > io.policy # cat io.policy dev weight class 8:16 300 2 Changelog (v1 -> v2) - Rename some structures - Use spin_lock_irqsave() and spin_lock_irqrestore() version to prevent from enabling the interrupts unconditionally. - Fix policy setup bug when switching to another io scheduler. - If a policy is available for a specific device, don't update weight and io class when writing "weight" and "iprio_class". - Fix a bug when parsing policy string. Signed-off-by: Gui Jianfeng Signed-off-by: Vivek Goyal Acked-by: Rik van Riel --- block/elevator-fq.c | 263 ++++++++++++++++++++++++++++++++++++++++++++++++++- block/elevator-fq.h | 10 ++ 2 files changed, 269 insertions(+), 4 deletions(-) diff --git a/block/elevator-fq.c b/block/elevator-fq.c index fd0a40f..e69de98 100644 --- a/block/elevator-fq.c +++ b/block/elevator-fq.c @@ -15,6 +15,7 @@ #include #include #include +#include #include "elevator-fq.h" const int elv_slice_sync = HZ / 10; @@ -1156,12 +1157,26 @@ EXPORT_SYMBOL(elv_io_group_set_async_queue); #ifdef CONFIG_GROUP_IOSCHED static void iocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup); -static void io_group_init_entity(struct io_cgroup *iocg, struct io_group *iog) +static struct io_policy_node *policy_search_node(const struct io_cgroup *iocg, + dev_t dev); +static void +io_group_init_entity(struct io_cgroup *iocg, struct io_group *iog, dev_t dev) { struct io_entity *entity = &iog->entity; + struct io_policy_node *pn; + unsigned long flags; + + spin_lock_irqsave(&iocg->lock, flags); + pn = policy_search_node(iocg, dev); + if (pn) { + entity->weight = pn->weight; + entity->ioprio_class = pn->ioprio_class; + } else { + entity->weight = iocg->weight; + entity->ioprio_class = iocg->ioprio_class; + } + spin_unlock_irqrestore(&iocg->lock, flags); - entity->weight = iocg->weight; - entity->ioprio_class = iocg->ioprio_class; entity->ioprio_changed = 1; entity->my_sd = &iog->sched_data; } @@ -1431,6 +1446,229 @@ io_cgroup_lookup_group(struct io_cgroup *iocg, void *key) return NULL; } +static int io_cgroup_policy_read(struct cgroup *cgrp, struct cftype *cft, + struct seq_file *m) +{ + struct io_cgroup *iocg; + struct io_policy_node *pn; + + iocg = cgroup_to_io_cgroup(cgrp); + + if (list_empty(&iocg->policy_list)) + goto out; + + seq_printf(m, "dev\tweight\tclass\n"); + + spin_lock_irq(&iocg->lock); + list_for_each_entry(pn, &iocg->policy_list, node) { + seq_printf(m, "%u:%u\t%u\t%hu\n", MAJOR(pn->dev), + MINOR(pn->dev), pn->weight, pn->ioprio_class); + } + spin_unlock_irq(&iocg->lock); +out: + return 0; +} + +static inline void policy_insert_node(struct io_cgroup *iocg, + struct io_policy_node *pn) +{ + list_add(&pn->node, &iocg->policy_list); +} + +/* Must be called with iocg->lock held */ +static inline void policy_delete_node(struct io_policy_node *pn) +{ + list_del(&pn->node); +} + +/* Must be called with iocg->lock held */ +static struct io_policy_node *policy_search_node(const struct io_cgroup *iocg, + dev_t dev) +{ + struct io_policy_node *pn; + + if (list_empty(&iocg->policy_list)) + return NULL; + + list_for_each_entry(pn, &iocg->policy_list, node) { + if (pn->dev == dev) + return pn; + } + + return NULL; +} + +static int 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 policy_parse_and_set(char *buf, struct io_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 == 4) + break; + } + + if (i != 3) + 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 = 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 > IO_WEIGHT_MAX) + return -EINVAL; + + newpn->weight = temp; + + if (s[2] == NULL) + return -EINVAL; + + ret = strict_strtoul(s[2], 10, &temp); + if (ret || temp < IOPRIO_CLASS_RT || temp > IOPRIO_CLASS_IDLE) + return -EINVAL; + newpn->ioprio_class = temp; + + return 0; +} + +static void update_iog_weight_prio(struct io_group *iog, struct io_cgroup *iocg, + struct io_policy_node *pn) +{ + if (pn->weight) { + iog->entity.weight = pn->weight; + iog->entity.ioprio_class = pn->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.weight = iocg->weight; + iog->entity.ioprio_class = iocg->ioprio_class; + + /* The same as above */ + smp_wmb(); + iog->entity.ioprio_changed = 1; + } +} + +static int io_cgroup_policy_write(struct cgroup *cgrp, struct cftype *cft, + const char *buffer) +{ + struct io_cgroup *iocg; + struct io_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->dev); + 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->dev == newpn->dev) + update_iog_weight_prio(iog, iocg, newpn); + } + spin_unlock_irq(&iocg->lock); + + cgroup_unlock(); + +free_newpn: + if (!keep_newpn) + kfree(newpn); +free_buf: + kfree(buf); + return ret; +} + #define SHOW_FUNCTION(__VAR) \ static u64 io_cgroup_##__VAR##_read(struct cgroup *cgroup, \ struct cftype *cftype) \ @@ -1463,6 +1701,7 @@ static int io_cgroup_##__VAR##_write(struct cgroup *cgroup, \ struct io_cgroup *iocg; \ struct io_group *iog; \ struct hlist_node *n; \ + struct io_policy_node *pn; \ \ if (val < (__MIN) || val > (__MAX)) \ return -EINVAL; \ @@ -1475,6 +1714,9 @@ static int io_cgroup_##__VAR##_write(struct cgroup *cgroup, \ spin_lock_irq(&iocg->lock); \ iocg->__VAR = (unsigned long)val; \ hlist_for_each_entry(iog, n, &iocg->group_data, group_node) { \ + pn = policy_search_node(iocg, iog->dev); \ + if (pn) \ + continue; \ iog->entity.__VAR = (unsigned long)val; \ smp_wmb(); \ iog->entity.ioprio_changed = 1; \ @@ -1610,6 +1852,12 @@ static int io_cgroup_disk_dequeue_read(struct cgroup *cgroup, struct cftype io_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, @@ -1660,6 +1908,7 @@ static struct cgroup_subsys_state *iocg_create(struct cgroup_subsys *subsys, INIT_HLIST_HEAD(&iocg->group_data); iocg->weight = IO_WEIGHT_DEFAULT; iocg->ioprio_class = IOPRIO_CLASS_BE; + INIT_LIST_HEAD(&iocg->policy_list); return &iocg->css; } @@ -1753,7 +2002,7 @@ io_group_chain_alloc(struct request_queue *q, void *key, struct cgroup *cgroup) sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); iog->dev = MKDEV(major, minor); - io_group_init_entity(iocg, iog); + io_group_init_entity(iocg, iog, iog->dev); atomic_set(&iog->ref, 0); @@ -2109,6 +2358,7 @@ static void iocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) struct io_group *iog; struct elv_fq_data *efqd; unsigned long uninitialized_var(flags); + struct io_policy_node *pn, *pntmp; /* * io groups are linked in two lists. One list is maintained @@ -2148,6 +2398,11 @@ remove_entry: goto remove_entry; done: + list_for_each_entry_safe(pn, pntmp, &iocg->policy_list, node) { + policy_delete_node(pn); + kfree(pn); + } + free_css_id(&io_subsys, &iocg->css); rcu_read_unlock(); BUG_ON(!hlist_empty(&iocg->group_data)); diff --git a/block/elevator-fq.h b/block/elevator-fq.h index 203250a..e0d5e54 100644 --- a/block/elevator-fq.h +++ b/block/elevator-fq.h @@ -157,12 +157,22 @@ struct io_group { struct request_list rl; }; +struct io_policy_node { + struct list_head node; + dev_t dev; + unsigned int weight; + unsigned short ioprio_class; +}; + struct io_cgroup { struct cgroup_subsys_state css; unsigned int weight; unsigned short ioprio_class; + /* list of io_policy_node */ + struct list_head policy_list; + spinlock_t lock; struct hlist_head group_data; }; -- 1.6.0.6