Ryo Tsuruta
2008-Jun-02 12:34 UTC
[PATCH 0/2] dm-ioband: I/O bandwidth controller v1.1.0: Introduction
Hi everyone, This is dm-ioband version 1.1.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc2-mm1. - Changes from 1.0.0 (posted on May 19, 2008): - Measures against high memory pressure. I/O requests to reclaim pages won't be blocked in dm-ioband even when the group doesn't have the right to issue any more I/Os. But it can keep to control the bandwidth of the group since these I/Os will be counted as debt of the group. - Performance tuning Improve the performance when a lot of ioband groups are created. It is useful when you want to control bandwidth on a per user basis. For example, you can create an ioband group and give an weight to a user once the user is logged in. The combination of dm-ioband, the cgroup memory resource controller and the CPU resource controller will work more effectively. I also announce that we have launched "Linux Block I/O Bandwidth Control Project" website http://people.valinux.co.jp/~ryov/bwctl/ . The goal of this project is to develop a block I/O bandwidth controller on Linux. You can find information about the followings: - dm-ioband This device mapper driver. - iobandctl An administration tool for dm-ioband, which makes it easy to configure the dm-ioband device. - Block I/O Tracking Block I/O tracking, which we call "bio cgroup", provides block I/O tracking mechanism. It makes dm-ioband be able to control the block I/O bandwidths even when it accepts delays write requests. Thanks, Ryo Tsuruta
Ryo Tsuruta
2008-Jun-02 12:36 UTC
[PATCH 1/2] dm-ioband: I/O bandwidth controller v1.1.0: Source code and patch
Here is the patch of dm-ioband. Based on 2.6.26-rc2-mm1 Signed-off-by: Ryo Tsuruta <ryov at valinux.co.jp> Signed-off-by: Hirokazu Takahashi <taka at valinux.co.jp> diff -uprN linux-2.6.26-rc2-mm1.orig/drivers/md/Kconfig linux-2.6.26-rc2-mm1/drivers/md/Kconfig --- linux-2.6.26-rc2-mm1.orig/drivers/md/Kconfig 2008-05-16 16:20:23.000000000 +0900 +++ linux-2.6.26-rc2-mm1/drivers/md/Kconfig 2008-06-02 20:44:44.000000000 +0900 @@ -271,4 +271,17 @@ config DM_UEVENT ---help--- Generate udev events for DM events. +config DM_IOBAND + tristate "I/O bandwidth control (EXPERIMENTAL)" + depends on BLK_DEV_DM && EXPERIMENTAL + ---help--- + This device-mapper target allows to define how the + available bandwidth of a storage device should be + shared between processes, cgroups, the partitions or the LUNs. + + Information on how to use dm-ioband is available in: + <file:Documentation/device-mapper/ioband.txt>. + + If unsure, say N. + endif # MD diff -uprN linux-2.6.26-rc2-mm1.orig/drivers/md/Makefile linux-2.6.26-rc2-mm1/drivers/md/Makefile --- linux-2.6.26-rc2-mm1.orig/drivers/md/Makefile 2008-05-16 16:20:23.000000000 +0900 +++ linux-2.6.26-rc2-mm1/drivers/md/Makefile 2008-06-02 20:44:44.000000000 +0900 @@ -7,6 +7,7 @@ dm-mod-objs := dm.o dm-table.o dm-target dm-multipath-objs := dm-path-selector.o dm-mpath.o dm-snapshot-objs := dm-snap.o dm-exception-store.o dm-mirror-objs := dm-raid1.o +dm-ioband-objs := dm-ioband-ctl.o dm-ioband-policy.o dm-ioband-type.o md-mod-objs := md.o bitmap.o raid456-objs := raid5.o raid6algos.o raid6recov.o raid6tables.o \ raid6int1.o raid6int2.o raid6int4.o \ @@ -36,6 +37,7 @@ obj-$(CONFIG_DM_MULTIPATH) += dm-multipa obj-$(CONFIG_DM_SNAPSHOT) += dm-snapshot.o obj-$(CONFIG_DM_MIRROR) += dm-mirror.o dm-log.o obj-$(CONFIG_DM_ZERO) += dm-zero.o +obj-$(CONFIG_DM_IOBAND) += dm-ioband.o quiet_cmd_unroll = UNROLL $@ cmd_unroll = $(PERL) $(srctree)/$(src)/unroll.pl $(UNROLL) \ diff -uprN linux-2.6.26-rc2-mm1.orig/drivers/md/dm-ioband-ctl.c linux-2.6.26-rc2-mm1/drivers/md/dm-ioband-ctl.c --- linux-2.6.26-rc2-mm1.orig/drivers/md/dm-ioband-ctl.c 1970-01-01 09:00:00.000000000 +0900 +++ linux-2.6.26-rc2-mm1/drivers/md/dm-ioband-ctl.c 2008-06-02 20:44:44.000000000 +0900 @@ -0,0 +1,1180 @@ +/* + * Copyright (C) 2008 VA Linux Systems Japan K.K. + * Authors: Hirokazu Takahashi <taka at valinux.co.jp> + * Ryo Tsuruta <ryov at valinux.co.jp> + * + * I/O bandwidth control + * + * This file is released under the GPL. + */ +#include <linux/module.h> +#include <linux/init.h> +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/workqueue.h> +#include <linux/raid/md.h> +#include <linux/rbtree.h> +#include "dm.h" +#include "dm-bio-list.h" +#include "dm-ioband.h" + +#define DM_MSG_PREFIX "ioband" +#define POLICY_PARAM_START 6 +#define POLICY_PARAM_DELIM "=:," + +static LIST_HEAD(ioband_device_list); +/* to protect ioband_device_list */ +static DEFINE_SPINLOCK(ioband_devicelist_lock); + +static void ioband_conduct(struct work_struct *); +static void ioband_hold_bio(struct ioband_group *, struct bio *); +static struct bio *ioband_pop_bio(struct ioband_group *); +static int ioband_set_param(struct ioband_group *, char *, char *); +static int ioband_group_attach(struct ioband_group *, int, char *); +static int ioband_group_type_select(struct ioband_group *, char *); + +long ioband_debug; /* just for debugging */ + +static int policy_init(struct ioband_device *dp, char *name, + int argc, char **argv) +{ + struct policy_type *p; + int r; + + for (p = dm_ioband_policy_type; (p->p_name); p++) { + if (!strcmp(name, p->p_name)) + break; + } + + dp->g_policy = p; + r = p->p_policy_init(dp, argc, argv); + if (!dp->g_hold_bio) + dp->g_hold_bio = ioband_hold_bio; + if (!dp->g_pop_bio) + dp->g_pop_bio = ioband_pop_bio; + return r; +} + +static struct ioband_device *alloc_ioband_device(char *name, char *policy, + int io_throttle, int io_limit, int argc, char **argv) + +{ + struct ioband_device *dp = NULL; + struct ioband_device *p; + struct ioband_device *new; + unsigned long flags; + + new = kzalloc(sizeof(struct ioband_device), GFP_KERNEL); + if (!new) + goto try_to_find; + + /* + * Prepare its own workqueue as generic_make_request() may potentially + * block the workqueue when submitting BIOs. + */ + new->g_ioband_wq = create_workqueue("kioband"); + if (!new->g_ioband_wq) { + kfree(new); + new = NULL; + goto try_to_find; + } + + INIT_WORK(&new->g_conductor, ioband_conduct); + INIT_LIST_HEAD(&new->g_groups); + INIT_LIST_HEAD(&new->g_list); + spin_lock_init(&new->g_lock); + bio_list_init(&new->g_urgent_bios); + new->g_io_throttle = io_throttle; + new->g_io_limit[0] = io_limit; + new->g_io_limit[1] = io_limit; + new->g_issued[0] = 0; + new->g_issued[1] = 0; + new->g_blocked = 0; + new->g_ref = 0; + new->g_flags = 0; + strlcpy(new->g_name, name, sizeof(new->g_name)); + new->g_policy = NULL; + new->g_hold_bio = NULL; + new->g_pop_bio = NULL; + init_waitqueue_head(&new->g_waitq); + +try_to_find: + spin_lock_irqsave(&ioband_devicelist_lock, flags); + list_for_each_entry(p, &ioband_device_list, g_list) { + if (!strcmp(p->g_name, name)) { + dp = p; + break; + } + } + if (!dp && (new)) { + if (policy_init(new, policy, argc, argv) == 0) { + dp = new; + new = NULL; + list_add_tail(&dp->g_list, &ioband_device_list); + } + } + spin_unlock_irqrestore(&ioband_devicelist_lock, flags); + + if (new) { + destroy_workqueue(new->g_ioband_wq); + kfree(new); + } + + return dp; +} + +static void release_ioband_device(struct ioband_device *dp) +{ + unsigned long flags; + + spin_lock_irqsave(&ioband_devicelist_lock, flags); + if (!list_empty(&dp->g_groups)) { + spin_unlock_irqrestore(&ioband_devicelist_lock, flags); + return; + } + list_del(&dp->g_list); + spin_unlock_irqrestore(&ioband_devicelist_lock, flags); + destroy_workqueue(dp->g_ioband_wq); + kfree(dp); +} + +static struct ioband_group *ioband_group_find(struct ioband_group *head, + int id) +{ + struct rb_node *node = head->c_group_root.rb_node; + + while (node) { + struct ioband_group *p + container_of(node, struct ioband_group, c_group_node); + + if (p->c_id == id || id == IOBAND_ID_ANY) + return p; + node = (id < p->c_id) ? node->rb_left : node->rb_right; + } + return NULL; +} + +static void ioband_group_add_node(struct rb_root *root, + struct ioband_group *gp) +{ + struct rb_node **new = &root->rb_node, *parent = NULL; + struct ioband_group *p; + + while (*new) { + p = container_of(*new, struct ioband_group, c_group_node); + parent = *new; + new = (gp->c_id < p->c_id) ? + &(*new)->rb_left : &(*new)->rb_right; + } + + rb_link_node(&gp->c_group_node, parent, new); + rb_insert_color(&gp->c_group_node, root); +} + +static int ioband_group_init(struct ioband_group *gp, + struct ioband_group *head, struct ioband_device *dp, int id, char *param) +{ + unsigned long flags; + int r; + + INIT_LIST_HEAD(&gp->c_list); + bio_list_init(&gp->c_blocked_bios); + bio_list_init(&gp->c_prio_bios); + gp->c_id = id; /* should be verified */ + gp->c_blocked = 0; + gp->c_prio_blocked = 0; + memset(gp->c_stat, 0, sizeof(gp->c_stat)); + init_waitqueue_head(&gp->c_waitq); + gp->c_flags = 0; + gp->c_group_root = RB_ROOT; + gp->c_banddev = dp; + + spin_lock_irqsave(&dp->g_lock, flags); + if (head && ioband_group_find(head, id)) { + spin_unlock_irqrestore(&dp->g_lock, flags); + DMWARN("ioband_group: id=%d already exists.", id); + return -EEXIST; + } + + dp->g_ref++; + list_add_tail(&gp->c_list, &dp->g_groups); + + r = dp->g_group_ctr(gp, param); + if (r) { + list_del(&gp->c_list); + dp->g_ref--; + return r; + } + + if (head) { + ioband_group_add_node(&head->c_group_root, gp); + gp->c_dev = head->c_dev; + gp->c_target = head->c_target; + } + + spin_unlock_irqrestore(&dp->g_lock, flags); + + return 0; +} + +static void ioband_group_release(struct ioband_group *head, + struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + + list_del(&gp->c_list); + if (head) + rb_erase(&gp->c_group_node, &head->c_group_root); + dp->g_ref--; + dp->g_group_dtr(gp); + kfree(gp); +} + +static void ioband_group_destroy_all(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + struct ioband_group *group; + unsigned long flags; + + spin_lock_irqsave(&dp->g_lock, flags); + while ((group = ioband_group_find(gp, IOBAND_ID_ANY))) + ioband_group_release(gp, group); + ioband_group_release(NULL, gp); + spin_unlock_irqrestore(&dp->g_lock, flags); +} + +static void ioband_group_stop(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + unsigned long flags; + + spin_lock_irqsave(&dp->g_lock, flags); + set_group_down(gp); + spin_unlock_irqrestore(&dp->g_lock, flags); + queue_work(dp->g_ioband_wq, &dp->g_conductor); + flush_workqueue(dp->g_ioband_wq); +} + +static void ioband_group_stop_all(struct ioband_group *head, int suspend) +{ + struct ioband_device *dp = head->c_banddev; + struct ioband_group *p; + struct rb_node *node; + unsigned long flags; + + spin_lock_irqsave(&dp->g_lock, flags); + for (node = rb_first(&head->c_group_root); node; node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + set_group_down(p); + if (suspend) { + set_group_suspended(p); + dprintk(KERN_ERR "ioband suspend: gp(%p)\n", p); + } + } + set_group_down(head); + if (suspend) { + set_group_suspended(head); + dprintk(KERN_ERR "ioband suspend: gp(%p)\n", head); + } + spin_unlock_irqrestore(&dp->g_lock, flags); + queue_work(dp->g_ioband_wq, &dp->g_conductor); + flush_workqueue(dp->g_ioband_wq); +} + +static void ioband_group_resume_all(struct ioband_group *head) +{ + struct ioband_device *dp = head->c_banddev; + struct ioband_group *p; + struct rb_node *node; + unsigned long flags; + + spin_lock_irqsave(&dp->g_lock, flags); + for (node = rb_first(&head->c_group_root); node; + node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + clear_group_down(p); + clear_group_suspended(p); + dprintk(KERN_ERR "ioband resume: gp(%p)\n", p); + } + clear_group_down(head); + clear_group_suspended(head); + dprintk(KERN_ERR "ioband resume: gp(%p)\n", head); + spin_unlock_irqrestore(&dp->g_lock, flags); +} + +/* + * Create a new band device: + * parameters: <device> <device-group-id> <io_throttle> <io_limit> + * <type> <policy> <policy-param...> <group-id:group-param...> + */ +static int ioband_ctr(struct dm_target *ti, unsigned int argc, char **argv) +{ + struct ioband_group *gp, *defgrp; + struct ioband_device *dp; + int io_throttle = DEFAULT_IO_THROTTLE; + int io_limit = DEFAULT_IO_LIMIT; + int i, r = 0; + long val, id; + char *param, *endp; + + if (argc < POLICY_PARAM_START) { + ti->error = "Requires " __stringify(POLICY_PARAM_START) + " or more arguments"; + return -EINVAL; + } + + if (strlen(argv[1]) > IOBAND_NAME_MAX) { + ti->error = "Ioband device name is too long"; + return -EINVAL; + } + dprintk(KERN_ERR "ioband_ctr ioband device name:%s\n", argv[1]); + + gp = kzalloc(sizeof(struct ioband_group), GFP_KERNEL); + if (!gp) { + ti->error = "Cannot allocate memory for ioband group"; + return -ENOMEM; + } + + r = dm_get_device(ti, argv[0], 0, ti->len, + dm_table_get_mode(ti->table), &gp->c_dev); + if (r) { + kfree(gp); + ti->error = "Device lookup failed"; + return r; + } + ti->private = gp; + + val = simple_strtol(argv[2], NULL, 0); + if (val > 0) + io_throttle = val; + + val = simple_strtol(argv[3], NULL, 0); + if (val > 0) + io_limit = val; + else { + struct request_queue *q; + + q = bdev_get_queue(gp->c_dev->bdev); + if (!q) { + dm_put_device(ti, gp->c_dev); + kfree(gp); + ti->error = "Can't get queue size"; + return -ENXIO; + } + dprintk(KERN_ERR "ioband_ctr nr_requests:%lu\n", + q->nr_requests); + io_limit = q->nr_requests; + } + + if (io_limit < io_throttle) + io_limit = io_throttle; + dprintk(KERN_ERR "ioband_ctr io_throttle:%d io_limit:%d\n", + io_throttle, io_limit); + + dp = alloc_ioband_device(argv[1], argv[5], io_throttle, io_limit, + argc - POLICY_PARAM_START, &argv[POLICY_PARAM_START]); + if (!dp) { + dm_put_device(ti, gp->c_dev); + kfree(gp); + ti->error = "Cannot create ioband device"; + return -EINVAL; + } + + for (i = POLICY_PARAM_START, defgrp = NULL; i < argc; i++) { + param = strpbrk(argv[i], POLICY_PARAM_DELIM); + if (!param) + continue; + if (param == argv[i]) { /* default ioband group */ + if (defgrp) { + ti->error + "Default ioband group specified twice"; + r = -EINVAL; + goto error; + } + param++; + r = ioband_group_init(gp, NULL, dp, + IOBAND_ID_ANY, param); + if (r) { + ti->error + "Cannot create default ioband group"; + goto error; + } + gp->c_target = ti; + defgrp = gp; + r = ioband_group_type_select(defgrp, argv[4]); + if (r) { + ti->error = "Cannot set ioband group type"; + goto error; + } + } else { /* sub ioband group */ + if (!defgrp) + break; + id = simple_strtol(argv[i], &endp, 0); + if (!strchr(POLICY_PARAM_DELIM, *endp)) { + ti->error = "Invalid ioband group ID"; + r = -EINVAL; + goto error; + } + param++; + r = ioband_group_attach(defgrp, id, param); + if (r) { + ti->error = "Cannot create ioband group"; + goto error; + } + } + } + + if (!defgrp) { + ti->error = "No default ioband group specified"; + r = -EINVAL; + goto error; + } + return 0; + +error: + dm_put_device(ti, gp->c_dev); + if (!defgrp) + kfree(gp); + else + ioband_group_destroy_all(gp); + release_ioband_device(dp); + return r; +} + +static void ioband_dtr(struct dm_target *ti) +{ + struct ioband_group *gp = ti->private; + struct ioband_device *dp = gp->c_banddev; + + ioband_group_stop_all(gp, 0); + dm_put_device(ti, gp->c_dev); + ioband_group_destroy_all(gp); + release_ioband_device(dp); +} + +static void ioband_hold_bio(struct ioband_group *gp, struct bio *bio) +{ + /* Todo: The list should be split into a read list and a write list */ + bio_list_add(&gp->c_blocked_bios, bio); +} + +static struct bio *ioband_pop_bio(struct ioband_group *gp) +{ + return bio_list_pop(&gp->c_blocked_bios); +} + +static int is_urgent_bio(struct bio *bio) +{ + struct page *page = bio_iovec_idx(bio, 0)->bv_page; + /* + * ToDo: A new flag should be added to struct bio, which indicates + * it contains urgent I/O requests. + */ + if (!PageReclaim(page)) + return 0; + if (PageSwapCache(page)) + return 2; + return 1; +} + +static inline void resume_to_accept_bios(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + + if (is_device_blocked(dp) + && dp->g_blocked < dp->g_io_limit[0]+dp->g_io_limit[1]) { + clear_device_blocked(dp); + wake_up_all(&dp->g_waitq); + } + if (is_group_blocked(gp)) { + clear_group_blocked(gp); + wake_up_all(&gp->c_waitq); + } +} + +static inline int device_should_block(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + + if (is_group_down(gp)) + return 0; + if (is_device_blocked(dp)) + return 1; + if (dp->g_blocked >= dp->g_io_limit[0] + dp->g_io_limit[1]) { + set_device_blocked(dp); + return 1; + } + return 0; +} + +static inline int group_should_block(struct ioband_group *gp, struct bio *bio) +{ + struct ioband_device *dp = gp->c_banddev; + + if (is_group_down(gp)) + return 0; + if (!is_urgent_bio(bio) && is_group_blocked(gp)) + return 1; + if (dp->g_should_block(gp)) { + set_group_blocked(gp); + return 1; + } + return 0; +} + +static void do_nothing(void) {} + +static void prevent_burst_bios(struct ioband_group *gp, struct bio *bio) +{ + struct ioband_device *dp = gp->c_banddev; + + if (!current->mm || current->flags & PF_BORROWED_MM) { + /* + * Kernel threads shouldn't be blocked easily since each of + * them may handle BIOs for several groups on several + * partitions. + */ + wait_event_lock_irq(dp->g_waitq, !device_should_block(gp), + dp->g_lock, do_nothing()); + } else { + wait_event_lock_irq(gp->c_waitq, !group_should_block(gp, bio), + dp->g_lock, do_nothing()); + } +} + +static inline int should_pushback_bio(struct ioband_group *gp) +{ + return is_group_suspended(gp) && dm_noflush_suspending(gp->c_target); +} + +static inline void prepare_to_issue(struct ioband_group *gp, struct bio *bio) +{ + struct ioband_device *dp = gp->c_banddev; + + dp->g_prepare_bio(gp, bio); + dp->g_issued[bio_data_dir(bio)]++; +} + +static inline int room_for_bio(struct ioband_device *dp) +{ + return dp->g_issued[0] < dp->g_io_limit[0] + || dp->g_issued[1] < dp->g_io_limit[1]; +} + +static void hold_bio(struct ioband_group *gp, struct bio *bio) +{ + struct ioband_device *dp = gp->c_banddev; + + dp->g_blocked++; + if (is_urgent_bio(bio)) { + /* + * ToDo: + * When barrier mode is supported, write bios sharing the same + * file system with the currnt one would be all moved + * to g_urgent_bios list. + * You don't have to care about barrier handling if the bio + * is for swapping. + */ + dp->g_prepare_bio(gp, bio); + bio_list_add(&dp->g_urgent_bios, bio); + } else { + gp->c_blocked++; + dp->g_hold_bio(gp, bio); + } +} + +static inline int room_for_bio_rw(struct ioband_device *dp, int direct) +{ + return dp->g_issued[direct] < dp->g_io_limit[direct]; +} + +static void push_prio_bio(struct ioband_group *gp, struct bio *bio, int direct) +{ + if (bio_list_empty(&gp->c_prio_bios)) + set_prio_queue(gp, direct); + bio_list_add(&gp->c_prio_bios, bio); + gp->c_prio_blocked++; +} + +static struct bio *pop_prio_bio(struct ioband_group *gp) +{ + struct bio *bio = bio_list_pop(&gp->c_prio_bios); + + if (bio_list_empty(&gp->c_prio_bios)) + clear_prio_queue(gp); + + if (bio) + gp->c_prio_blocked--; + return bio; +} + +static void release_urgent_bios(struct ioband_device *dp, + struct bio_list *issue_list, struct bio_list *pushback_list) +{ + struct bio *bio; + + if (bio_list_empty(&dp->g_urgent_bios)) + return; + while (room_for_bio_rw(dp, 1)) { + bio = bio_list_pop(&dp->g_urgent_bios); + if (!bio) + return; + dp->g_blocked--; + dp->g_issued[1]++; + bio_list_add(issue_list, bio); + } +} + +static void release_prio_bios(struct ioband_group *gp, + struct bio_list *issue_list, struct bio_list *pushback_list) +{ + struct ioband_device *dp = gp->c_banddev; + struct bio *bio; + int direct; + + if (bio_list_empty(&gp->c_prio_bios)) + return; + direct = prio_queue_direct(gp); + while (room_for_bio_rw(dp, direct)) { + bio = pop_prio_bio(gp); + if (!bio) + return; + dp->g_blocked--; + gp->c_blocked--; + if (!gp->c_blocked) + resume_to_accept_bios(gp); + prepare_to_issue(gp, bio); + if (is_group_suspended(gp)) + bio_list_add(pushback_list, bio); + else + bio_list_add(issue_list, bio); + } +} + +static void release_norm_bios(struct ioband_group *gp, + struct bio_list *issue_list, struct bio_list *pushback_list) +{ + struct ioband_device *dp = gp->c_banddev; + struct bio *bio; + int direct; + + while (dp->g_can_submit(gp) && gp->c_blocked - gp->c_prio_blocked) { + if (!room_for_bio(dp)) + return; + bio = dp->g_pop_bio(gp); + if (!bio) + return; + + direct = bio_data_dir(bio); + if (!room_for_bio_rw(dp, direct)) { + push_prio_bio(gp, bio, direct); + continue; + } + dp->g_blocked--; + gp->c_blocked--; + if (!gp->c_blocked) + resume_to_accept_bios(gp); + prepare_to_issue(gp, bio); + if (is_group_suspended(gp)) + bio_list_add(pushback_list, bio); + else + bio_list_add(issue_list, bio); + } +} + +static inline void release_bios(struct ioband_group *gp, + struct bio_list *issue_list, struct bio_list *pushback_list) +{ + + release_prio_bios(gp, issue_list, pushback_list); + release_norm_bios(gp, issue_list, pushback_list); +} + +static struct ioband_group *ioband_group_get( + struct ioband_group *head, struct bio *bio) +{ + struct ioband_group *gp; + + if (!head->c_type->t_getid) + return head; + + gp = ioband_group_find(head, head->c_type->t_getid(bio)); + + if (!gp) + gp = head; + return gp; +} + +/* + * Start to control the bandwidth once the number of uncompleted BIOs + * exceeds the value of "io_throttle". + */ +static int ioband_map(struct dm_target *ti, struct bio *bio, + union map_info *map_context) +{ + struct ioband_group *gp = ti->private; + struct ioband_group_stat *bws; + struct ioband_device *dp = gp->c_banddev; + unsigned long flags; + +#if 0 /* not supported yet */ + if (bio_barrier(bio)) + return -EOPNOTSUPP; +#endif + + spin_lock_irqsave(&dp->g_lock, flags); + gp = ioband_group_get(gp, bio); + prevent_burst_bios(gp, bio); + if (should_pushback_bio(gp)) { + spin_unlock_irqrestore(&dp->g_lock, flags); + return DM_MAPIO_REQUEUE; + } + + bio->bi_bdev = gp->c_dev->bdev; + bio->bi_sector -= ti->begin; + bws = &gp->c_stat[bio_data_dir(bio)]; + bws->sectors += bio_sectors(bio); +retry: + if (!gp->c_blocked && room_for_bio_rw(dp, bio_data_dir(bio))) { + if (dp->g_can_submit(gp)) { + prepare_to_issue(gp, bio); + bws->immediate++; + spin_unlock_irqrestore(&dp->g_lock, flags); + return DM_MAPIO_REMAPPED; + } else if (dp->g_issued[0] + dp->g_issued[1] == 0) { + if (!dp->g_blocked && dp->g_restart_bios(dp)) { + dprintk(KERN_ERR "ioband_map: token refilled " + "gp:%p bio:%p\n", gp, bio); + goto retry; + } + } + } + hold_bio(gp, bio); + bws->deferred++; + spin_unlock_irqrestore(&dp->g_lock, flags); + + return DM_MAPIO_SUBMITTED; +} + +/* + * Select the best group to resubmit its BIOs. + */ +static struct ioband_group *choose_best_group(struct ioband_device *dp) +{ + struct ioband_group *gp; + struct ioband_group *best = NULL; + int highest = 0; + int pri; + + /* Todo: The algorithm should be optimized. + * It would be better to use rbtree. + */ + list_for_each_entry(gp, &dp->g_groups, c_list) { + if (!gp->c_blocked || !room_for_bio(dp)) + continue; + if (gp->c_blocked == gp->c_prio_blocked + && !room_for_bio_rw(dp, prio_queue_direct(gp))) { + continue; + } + pri = dp->g_can_submit(gp); + if (pri > highest) { + highest = pri; + best = gp; + } + } + + return best; +} + +/* + * This function is called right after it becomes able to resubmit BIOs. + * It selects the best BIOs and passes them to the underlying layer. + */ +static void ioband_conduct(struct work_struct *work) +{ + struct ioband_device *dp + container_of(work, struct ioband_device, g_conductor); + struct ioband_group *gp = NULL; + struct bio *bio; + unsigned long flags; + struct bio_list issue_list, pushback_list; + + bio_list_init(&issue_list); + bio_list_init(&pushback_list); + + spin_lock_irqsave(&dp->g_lock, flags); +retry: + release_urgent_bios(dp, &issue_list, &pushback_list); + while (dp->g_blocked && (gp = choose_best_group(dp))) + release_bios(gp, &issue_list, &pushback_list); + + if (dp->g_blocked + && dp->g_issued[0] + dp->g_issued[1] < dp->g_io_throttle) { + dprintk(KERN_ERR "ioband_conduct: token expired dp:%p " + "issued(%d,%d) g_blocked(%d)\n", dp, + dp->g_issued[0], dp->g_issued[1], dp->g_blocked); + if (dp->g_restart_bios(dp)) + goto retry; + } + + spin_unlock_irqrestore(&dp->g_lock, flags); + + while ((bio = bio_list_pop(&issue_list))) + generic_make_request(bio); + while ((bio = bio_list_pop(&pushback_list))) + bio_endio(bio, -EIO); +} + +static int ioband_end_io(struct dm_target *ti, struct bio *bio, + int error, union map_info *map_context) +{ + struct ioband_group *gp = ti->private; + struct ioband_device *dp = gp->c_banddev; + unsigned long flags; + int r = error; + + /* + * XXX: A new error code for device mapper devices should be used + * rather than EIO. + */ + if (error == -EIO && should_pushback_bio(gp)) { + /* This ioband device is suspending */ + r = DM_ENDIO_REQUEUE; + } + /* + * Todo: The algorithm should be optimized to eliminate the spinlock. + */ + spin_lock_irqsave(&dp->g_lock, flags); + dp->g_issued[bio_data_dir(bio)]--; + + /* + * Todo: It would be better to introduce high/low water marks here + * not to kick the workqueues so often. + */ + if (dp->g_blocked) + queue_work(dp->g_ioband_wq, &dp->g_conductor); + spin_unlock_irqrestore(&dp->g_lock, flags); + return r; +} + +static void ioband_presuspend(struct dm_target *ti) +{ + struct ioband_group *gp = ti->private; + ioband_group_stop_all(gp, 1); +} + +static void ioband_resume(struct dm_target *ti) +{ + struct ioband_group *gp = ti->private; + ioband_group_resume_all(gp); +} + + +static void ioband_group_status(struct ioband_group *gp, int *szp, + char *result, unsigned int maxlen) +{ + struct ioband_group_stat *bws; + unsigned long reqs; + int i, sz = *szp; /* used in DMEMIT() */ + + DMEMIT(" %d", gp->c_id); + for (i = 0; i < 2; i++) { + bws = &gp->c_stat[i]; + reqs = bws->immediate + bws->deferred; + DMEMIT(" %lu %lu %lu", + bws->immediate + bws->deferred, bws->deferred, + bws->sectors); + } + *szp = sz; +} + +static int ioband_status(struct dm_target *ti, status_type_t type, + char *result, unsigned int maxlen) +{ + struct ioband_group *gp = ti->private, *p; + struct ioband_device *dp = gp->c_banddev; + struct rb_node *node; + int sz = 0; /* used in DMEMIT() */ + unsigned long flags; + + switch (type) { + case STATUSTYPE_INFO: + spin_lock_irqsave(&dp->g_lock, flags); + DMEMIT("%s", dp->g_name); + ioband_group_status(gp, &sz, result, maxlen); + for (node = rb_first(&gp->c_group_root); node; + node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + ioband_group_status(p, &sz, result, maxlen); + } + spin_unlock_irqrestore(&dp->g_lock, flags); + break; + + case STATUSTYPE_TABLE: + spin_lock_irqsave(&dp->g_lock, flags); + DMEMIT("%s %s %d %d %s %s", + gp->c_dev->name, dp->g_name, + dp->g_io_throttle, dp->g_io_limit[0], + gp->c_type->t_name, dp->g_policy->p_name); + dp->g_show(gp, &sz, result, maxlen); + spin_unlock_irqrestore(&dp->g_lock, flags); + break; + } + + return 0; +} + +static int ioband_group_type_select(struct ioband_group *gp, char *name) +{ + struct ioband_device *dp = gp->c_banddev; + struct group_type *t; + unsigned long flags; + + for (t = dm_ioband_group_type; (t->t_name); t++) { + if (!strcmp(name, t->t_name)) + break; + } + if (!t->t_name) { + DMWARN("ioband type select: %s isn't supported.", name); + return -EINVAL; + } + spin_lock_irqsave(&dp->g_lock, flags); + if (!RB_EMPTY_ROOT(&gp->c_group_root)) { + spin_unlock_irqrestore(&dp->g_lock, flags); + return -EBUSY; + } + gp->c_type = t; + spin_unlock_irqrestore(&dp->g_lock, flags); + + return 0; +} + +static int split_string(char *s, char **v) +{ + long id = IOBAND_ID_ANY; + char *p, *q; + + p = strsep(&s, POLICY_PARAM_DELIM); + q = strsep(&s, POLICY_PARAM_DELIM); + if (!q) { + *v = p; + } else { + id = simple_strtol(p, NULL, 0); + *v = q; + } + return id; +} + +static int ioband_set_param(struct ioband_group *gp, char *cmd, char *value) +{ + struct ioband_device *dp = gp->c_banddev; + char *val_str; + int id; + unsigned long flags; + int r; + + id = split_string(value, &val_str); + + spin_lock_irqsave(&dp->g_lock, flags); + if (id != IOBAND_ID_ANY) { + gp = ioband_group_find(gp, id); + if (!gp) { + spin_unlock_irqrestore(&dp->g_lock, flags); + DMWARN("ioband_set_param: id=%d not found.", id); + return -EINVAL; + } + } + r = dp->g_set_param(gp, cmd, val_str); + spin_unlock_irqrestore(&dp->g_lock, flags); + return r; +} + +static int ioband_group_attach(struct ioband_group *gp, int id, char *param) +{ + struct ioband_device *dp = gp->c_banddev; + struct ioband_group *sub_gp; + int r; + + if (id < 0) { + DMWARN("ioband_group_attach: invalid id:%d", id); + return -EINVAL; + } + if (!gp->c_type->t_getid) { + DMWARN("ioband_group_attach: " + "no ioband group type is specified"); + return -EINVAL; + } + + sub_gp = kzalloc(sizeof(struct ioband_group), GFP_KERNEL); + if (!sub_gp) + return -ENOMEM; + + r = ioband_group_init(sub_gp, gp, dp, id, param); + if (r < 0) { + kfree(sub_gp); + return r; + } + return 0; +} + +static int ioband_group_detach(struct ioband_group *gp, int id) +{ + struct ioband_device *dp = gp->c_banddev; + struct ioband_group *sub_gp; + unsigned long flags; + + if (id < 0) { + DMWARN("ioband_group_detach: invalid id:%d", id); + return -EINVAL; + } + spin_lock_irqsave(&dp->g_lock, flags); + sub_gp = ioband_group_find(gp, id); + spin_unlock_irqrestore(&dp->g_lock, flags); + if (!sub_gp) { + DMWARN("ioband_group_detach: invalid id:%d", id); + return -EINVAL; + } + ioband_group_stop(sub_gp); + spin_lock_irqsave(&dp->g_lock, flags); + ioband_group_release(gp, sub_gp); + spin_unlock_irqrestore(&dp->g_lock, flags); + return 0; +} + +/* + * Message parameters: + * "policy" <name> + * ex) + * "policy" "weight" + * "type" "none"|"pid"|"pgrp"|"node"|"cpuset"|"cgroup"|"user"|"gid" + * "io_throttle" <value> + * "io_limit" <value> + * "attach" <group id> + * "detach" <group id> + * "any-command" <group id>:<value> + * ex) + * "weight" 0:<value> + * "token" 24:<value> + */ +static int ioband_message(struct dm_target *ti, unsigned int argc, char **argv) +{ + struct ioband_group *gp = ti->private, *p; + struct ioband_device *dp = gp->c_banddev; + struct rb_node *node; + long val = 0; + int r = 0; + unsigned long flags; + + if (argc == 1 && !strcmp(argv[0], "reset")) { + spin_lock_irqsave(&dp->g_lock, flags); + memset(gp->c_stat, 0, sizeof(gp->c_stat)); + for (node = rb_first(&gp->c_group_root); node; + node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + memset(p->c_stat, 0, sizeof(p->c_stat)); + } + spin_unlock_irqrestore(&dp->g_lock, flags); + return 0; + } + + if (argc != 2) { + DMWARN("Unrecognised band message received."); + return -EINVAL; + } + if (!strcmp(argv[0], "debug")) { + ioband_debug = simple_strtol(argv[1], NULL, 0); + if (ioband_debug < 0) + ioband_debug = 0; + return 0; + } else if (!strcmp(argv[0], "io_throttle")) { + val = simple_strtol(argv[1], NULL, 0); + spin_lock_irqsave(&dp->g_lock, flags); + if (val < 0 || + val > dp->g_io_limit[0] || val > dp->g_io_limit[1]) { + spin_unlock_irqrestore(&dp->g_lock, flags); + return -EINVAL; + } + dp->g_io_throttle = (val == 0) ? DEFAULT_IO_THROTTLE : val; + spin_unlock_irqrestore(&dp->g_lock, flags); + ioband_set_param(gp, argv[0], argv[1]); + return 0; + } else if (!strcmp(argv[0], "io_limit")) { + val = simple_strtol(argv[1], NULL, 0); + if (val == 0) { + struct request_queue *q; + + q = bdev_get_queue(gp->c_dev->bdev); + if (!q) + return -ENXIO; + val = q->nr_requests; + } + spin_lock_irqsave(&dp->g_lock, flags); + if (val < dp->g_io_throttle) { + spin_unlock_irqrestore(&dp->g_lock, flags); + return -EINVAL; + } + dp->g_io_limit[0] = val; + dp->g_io_limit[1] = val; + spin_unlock_irqrestore(&dp->g_lock, flags); + ioband_set_param(gp, argv[0], argv[1]); + return 0; + } else if (!strcmp(argv[0], "type")) { + return ioband_group_type_select(gp, argv[1]); + } else if (!strcmp(argv[0], "attach")) { + long id = simple_strtol(argv[1], NULL, 0); + return ioband_group_attach(gp, id, NULL); + } else if (!strcmp(argv[0], "detach")) { + long id = simple_strtol(argv[1], NULL, 0); + return ioband_group_detach(gp, id); + } else { + /* message anycommand <group-id>:<value> */ + r = ioband_set_param(gp, argv[0], argv[1]); + if (r < 0) + DMWARN("Unrecognised band message received."); + return r; + } + return 0; +} + +static struct target_type ioband_target = { + .name = "ioband", + .module = THIS_MODULE, + .version = {1, 1, 0}, + .ctr = ioband_ctr, + .dtr = ioband_dtr, + .map = ioband_map, + .end_io = ioband_end_io, + .presuspend = ioband_presuspend, + .resume = ioband_resume, + .status = ioband_status, + .message = ioband_message, +}; + +static int __init dm_ioband_init(void) +{ + int r; + + r = dm_register_target(&ioband_target); + if (r < 0) { + DMERR("register failed %d", r); + return r; + } + return r; +} + +static void __exit dm_ioband_exit(void) +{ + int r; + + r = dm_unregister_target(&ioband_target); + if (r < 0) + DMERR("unregister failed %d", r); +} + +module_init(dm_ioband_init); +module_exit(dm_ioband_exit); + +MODULE_DESCRIPTION(DM_NAME " I/O bandwidth control"); +MODULE_AUTHOR("Hirokazu Takahashi <taka at valinux.co.jp>, " + "Ryo Tsuruta <ryov at valinux.co.jp"); +MODULE_LICENSE("GPL"); diff -uprN linux-2.6.26-rc2-mm1.orig/drivers/md/dm-ioband-policy.c linux-2.6.26-rc2-mm1/drivers/md/dm-ioband-policy.c --- linux-2.6.26-rc2-mm1.orig/drivers/md/dm-ioband-policy.c 1970-01-01 09:00:00.000000000 +0900 +++ linux-2.6.26-rc2-mm1/drivers/md/dm-ioband-policy.c 2008-06-02 20:44:44.000000000 +0900 @@ -0,0 +1,291 @@ +/* + * Copyright (C) 2008 VA Linux Systems Japan K.K. + * + * I/O bandwidth control + * + * This file is released under the GPL. + */ +#include <linux/bio.h> +#include <linux/workqueue.h> +#include <linux/rbtree.h> +#include "dm.h" +#include "dm-bio-list.h" +#include "dm-ioband.h" + +/* + * The following functions determine when and which BIOs should + * be submitted to control the I/O flow. + * It is possible to add a new BIO scheduling policy with it. + */ + + +/* + * Functions for weight balancing policy based on the number of I/Os. + */ +#define DEFAULT_WEIGHT 100 +#define DEFAULT_TOKENBASE 8192 +#define IOBAND_IOPRIO_BASE 100 + +static int make_global_epoch(struct ioband_device *dp) +{ + dp->g_epoch++; +#if 0 /* this will also work correctly */ + if (dp->g_blocked) + queue_work(dp->g_ioband_wq, &dp->g_conductor); + return 0; +#endif + dprintk(KERN_ERR "make_epoch %d --> %d\n", + dp->g_epoch-1, dp->g_epoch); + return 1; +} + +static inline int make_epoch(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + + if (gp->c_my_epoch != dp->g_epoch) { + gp->c_my_epoch = dp->g_epoch; + return 1; + } + return 0; +} + +static inline int iopriority(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + int iopri; + + iopri = gp->c_token*IOBAND_IOPRIO_BASE/gp->c_token_init_value + 1; + if (gp->c_my_epoch != dp->g_epoch) + iopri += IOBAND_IOPRIO_BASE; + if (is_group_down(gp)) + iopri += IOBAND_IOPRIO_BASE*2; + + return iopri; +} + +static int is_token_left(struct ioband_group *gp) +{ + if (gp->c_token > 0) + return iopriority(gp); + + if (is_group_down(gp)) { + gp->c_token = gp->c_token_init_value; + return iopriority(gp); + } + if (make_epoch(gp)) { + gp->c_token += gp->c_token_init_value; + dprintk(KERN_ERR "refill token: gp:%p token:%d->%d\n", + gp, gp->c_token - gp->c_token_init_value, gp->c_token); + if (gp->c_token > 0) + return iopriority(gp); + dprintk(KERN_ERR "refill token: yet empty gp:%p token:%d\n", + gp, gp->c_token); + } + return 0; +} + +static void prepare_token(struct ioband_group *gp, struct bio *bio) +{ + gp->c_token--; +} + +static void set_weight(struct ioband_group *gp, int new) +{ + struct ioband_device *dp = gp->c_banddev; + struct ioband_group *p; + + dp->g_weight_total += (new - gp->c_weight); + gp->c_weight = new; + + list_for_each_entry(p, &dp->g_groups, c_list) { + /* Fixme: it might overflow */ + p->c_token = p->c_token_init_value + dp->g_token_base * p->c_weight / dp->g_weight_total + 1; + p->c_limit + (dp->g_io_limit[0] + dp->g_io_limit[1]) * + p->c_weight / dp->g_weight_total + 1; + } +} + +static int policy_weight_ctr(struct ioband_group *gp, char *arg) +{ + struct ioband_device *dp = gp->c_banddev; + char *endp; + long weight; + + if (!arg) + weight = DEFAULT_WEIGHT; + else { + weight = simple_strtol(arg, &endp, 0); + if (*endp != '\0' || weight <= 0) + return -EINVAL; + } + + gp->c_my_epoch = dp->g_epoch; + gp->c_weight = 0; + set_weight(gp, weight); + return 0; +} + +static void policy_weight_dtr(struct ioband_group *gp) +{ + set_weight(gp, 0); +} + +static int policy_weight_param(struct ioband_group *gp, char *cmd, char *value) +{ + struct ioband_device *dp = gp->c_banddev; + long val = simple_strtol(value, NULL, 0); + int r = 0; + + if (!strcmp(cmd, "weight")) { + if (val > 0) + set_weight(gp, val); + else + r = -EINVAL; + } else if (!strcmp(cmd, "token")) { + if (val > 0) { + dp->g_token_base = val; + set_weight(gp, gp->c_weight); + } else + r = -EINVAL; + } else if (!strcmp(cmd, "io_limit")) { + set_weight(gp, gp->c_weight); + } else { + r = -EINVAL; + } + return r; +} + +static void policy_weight_show(struct ioband_group *gp, int *szp, + char *result, unsigned int maxlen) +{ + struct ioband_group *p; + struct ioband_device *dp = gp->c_banddev; + struct rb_node *node; + int sz = *szp; /* used in DMEMIT() */ + + DMEMIT(" %d :%d", dp->g_token_base, gp->c_weight); + + for (node = rb_first(&gp->c_group_root); node; node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + DMEMIT(" %d:%d", p->c_id, p->c_weight); + } + *szp = sz; +} + +static int is_queue_full(struct ioband_group *gp) +{ + return gp->c_blocked >= gp->c_limit; +} + + +/* + * <Method> <description> + * g_can_submit : To determine whether a given group has the right to + * submit BIOs. The larger the return value the higher the + * priority to submit. Zero means it has no right. + * g_prepare_bio : Called right before submitting each BIO. + * g_restart_bios : Called if this ioband device has some BIOs blocked but none + * of them can be submitted now. This method has to + * reinitialize the data to restart to submit BIOs and return + * 0 or 1. + * The return value 0 means that it has become able to submit + * them now so that this ioband device will continue its work. + * The return value 1 means that it is still unable to submit + * them so that this device will stop its work. And this + * policy module has to reactivate the device when it gets + * to be able to submit BIOs. + * g_hold_bio : To hold a given BIO until it is submitted. + * The default function is used when this method is undefined. + * g_pop_bio : To select and get the best BIO to submit. + * g_group_ctr : To initalize the policy own members of struct ioband_group. + * g_group_dtr : Called when struct ioband_group is removed. + * g_set_param : To update the policy own date. + * The parameters can be passed through "dmsetup message" + * command. + * g_should_block : Called every time this ioband device receive a BIO. + * Return 1 if a given group can't receive any more BIOs, + * otherwise return 0. + * g_show : Show the configuration. + */ +static int policy_weight_init(struct ioband_device *dp, int argc, char **argv) +{ + char *endp; + long val; + + if (argc < 1) + return -EINVAL; + + val = simple_strtol(argv[0], &endp, 0); + if (*endp != '\0' || val < 0) + return -EINVAL; + if (val == 0) + val = DEFAULT_TOKENBASE; + + dp->g_can_submit = is_token_left; + dp->g_prepare_bio = prepare_token; + dp->g_restart_bios = make_global_epoch; + dp->g_group_ctr = policy_weight_ctr; + dp->g_group_dtr = policy_weight_dtr; + dp->g_set_param = policy_weight_param; + dp->g_should_block = is_queue_full; + dp->g_show = policy_weight_show; + + dp->g_token_base = val; + dp->g_epoch = 0; + dp->g_weight_total = 0; + return 0; +} +/* weight balancing policy based on the number of I/Os. --- End --- */ + + +/* + * Functions for weight balancing policy based on I/O size. + * It just borrows a lot of functions from the regular weight balancing policy. + */ +static void w2_prepare_token(struct ioband_group *gp, struct bio *bio) +{ + gp->c_token -= bio_sectors(bio); +} + +static int w2_policy_weight_init(struct ioband_device *dp, + int argc, char **argv) +{ + char *endp; + long val; + int r = 0; + + if (argc < 1) + return -EINVAL; + + val = simple_strtol(argv[0], &endp, 0); + if (*endp != '\0' || val < 0) + return -EINVAL; + if (val == 0) + val = DEFAULT_TOKENBASE << (PAGE_SHIFT - 9); + + r = policy_weight_init(dp, argc, argv); + if (r < 0) + return r; + + dp->g_prepare_bio = w2_prepare_token; + dp->g_token_base = val; + return 0; +} +/* weight balancing policy based on I/O size. --- End --- */ + + +static int policy_default_init(struct ioband_device *dp, + int argc, char **argv) /*XXX*/ +{ + return policy_weight_init(dp, argc, argv); /* temp */ +} + +struct policy_type dm_ioband_policy_type[] = { + {"default", policy_default_init}, + {"weight", policy_weight_init}, + {"weight-iosize", w2_policy_weight_init}, + {NULL, policy_default_init} +}; diff -uprN linux-2.6.26-rc2-mm1.orig/drivers/md/dm-ioband-type.c linux-2.6.26-rc2-mm1/drivers/md/dm-ioband-type.c --- linux-2.6.26-rc2-mm1.orig/drivers/md/dm-ioband-type.c 1970-01-01 09:00:00.000000000 +0900 +++ linux-2.6.26-rc2-mm1/drivers/md/dm-ioband-type.c 2008-06-02 20:44:44.000000000 +0900 @@ -0,0 +1,76 @@ +/* + * Copyright (C) 2008 VA Linux Systems Japan K.K. + * + * I/O bandwidth control + * + * This file is released under the GPL. + */ +#include <linux/bio.h> +#include "dm.h" +#include "dm-bio-list.h" +#include "dm-ioband.h" + +/* + * Any I/O bandwidth can be divided into several bandwidth groups, each of which + * has its own unique ID. The following functions are called to determine + * which group a given BIO belongs to and return the ID of the group. + */ + +/* ToDo: unsigned long value would be better for group ID */ + +static int ioband_process_id(struct bio *bio) +{ + /* + * This function will work for KVM and Xen. + */ + return (int)current->tgid; +} + +static int ioband_process_group(struct bio *bio) +{ + return (int)task_pgrp_nr(current); +} + +static int ioband_uid(struct bio *bio) +{ + return (int)current->uid; +} + +static int ioband_gid(struct bio *bio) +{ + return (int)current->gid; +} + +static int ioband_cpuset(struct bio *bio) +{ + return 0; /* not implemented yet */ +} + +static int ioband_node(struct bio *bio) +{ + return 0; /* not implemented yet */ +} + +static int ioband_cgroup(struct bio *bio) +{ + /* + * This function should return the ID of the cgroup which issued "bio". + * The ID of the cgroup which the current process belongs to won't be + * suitable ID for this purpose, since some BIOs will be handled by kernel + * threads like aio or pdflush on behalf of the process requesting the BIOs. + */ + return 0; /* not implemented yet */ +} + +struct group_type dm_ioband_group_type[] = { + {"none", NULL}, + {"pgrp", ioband_process_group}, + {"pid", ioband_process_id}, + {"node", ioband_node}, + {"cpuset", ioband_cpuset}, + {"cgroup", ioband_cgroup}, + {"user", ioband_uid}, + {"uid", ioband_uid}, + {"gid", ioband_gid}, + {NULL, NULL} +}; diff -uprN linux-2.6.26-rc2-mm1.orig/drivers/md/dm-ioband.h linux-2.6.26-rc2-mm1/drivers/md/dm-ioband.h --- linux-2.6.26-rc2-mm1.orig/drivers/md/dm-ioband.h 1970-01-01 09:00:00.000000000 +0900 +++ linux-2.6.26-rc2-mm1/drivers/md/dm-ioband.h 2008-06-02 20:44:44.000000000 +0900 @@ -0,0 +1,153 @@ +/* + * Copyright (C) 2008 VA Linux Systems Japan K.K. + * + * I/O bandwidth control + * + * This file is released under the GPL. + */ + +#include <linux/version.h> +#include <linux/wait.h> + +#define DEFAULT_IO_THROTTLE 4 +#define DEFAULT_IO_LIMIT 128 +#define IOBAND_NAME_MAX 31 +#define IOBAND_ID_ANY (-1) + +struct ioband_group; + +struct ioband_device { + struct list_head g_groups; + struct work_struct g_conductor; + struct workqueue_struct *g_ioband_wq; + struct bio_list g_urgent_bios; + int g_io_throttle; + int g_io_limit[2]; + int g_issued[2]; + int g_blocked; + spinlock_t g_lock; + wait_queue_head_t g_waitq; + + int g_ref; /* just for debugging */ + struct list_head g_list; + int g_flags; + char g_name[IOBAND_NAME_MAX + 1]; + struct policy_type *g_policy; + + /* policy dependent */ + int (*g_can_submit)(struct ioband_group *); + void (*g_prepare_bio)(struct ioband_group *, struct bio *); + int (*g_restart_bios)(struct ioband_device *); + void (*g_hold_bio)(struct ioband_group *, struct bio *); + struct bio * (*g_pop_bio)(struct ioband_group *); + int (*g_group_ctr)(struct ioband_group *, char *); + void (*g_group_dtr)(struct ioband_group *); + int (*g_set_param)(struct ioband_group *, char *cmd, char *value); + int (*g_should_block)(struct ioband_group *); + void (*g_show)(struct ioband_group *, int *, char *, unsigned int); + + /* members for weight balancing policy */ + int g_epoch; + int g_weight_total; + int g_token_base; + +}; + +struct ioband_group_stat { + unsigned long sectors; + unsigned long immediate; + unsigned long deferred; +}; + +struct ioband_group { + struct list_head c_list; + struct ioband_device *c_banddev; + struct dm_dev *c_dev; + struct dm_target *c_target; + struct bio_list c_blocked_bios; + struct bio_list c_prio_bios; + struct rb_root c_group_root; + struct rb_node c_group_node; + int c_id; /* should be unsigned long or unsigned long long */ + char c_name[IOBAND_NAME_MAX + 1]; /* rfu */ + int c_blocked; + int c_prio_blocked; + wait_queue_head_t c_waitq; + int c_flags; + struct ioband_group_stat c_stat[2]; /* hold rd/wr status */ + struct group_type *c_type; + + /* members for weight balancing policy */ + int c_weight; + int c_my_epoch; + int c_token; + int c_token_init_value; + int c_limit; + + /* rfu */ + /* struct bio_list c_ordered_tag_bios; */ +}; + +#define DEV_BIO_BLOCKED 1 + +#define set_device_blocked(dp) ((dp)->g_flags |= DEV_BIO_BLOCKED) +#define clear_device_blocked(dp) ((dp)->g_flags &= ~DEV_BIO_BLOCKED) +#define is_device_blocked(dp) ((dp)->g_flags & DEV_BIO_BLOCKED) + + +#define IOG_PRIO_BIO_WRITE 1 +#define IOG_PRIO_QUEUE 2 +#define IOG_BIO_BLOCKED 4 +#define IOG_GOING_DOWN 8 +#define IOG_SUSPENDED 16 + +#define set_group_blocked(gp) ((gp)->c_flags |= IOG_BIO_BLOCKED) +#define clear_group_blocked(gp) ((gp)->c_flags &= ~IOG_BIO_BLOCKED) +#define is_group_blocked(gp) ((gp)->c_flags & IOG_BIO_BLOCKED) + +#define set_group_down(gp) ((gp)->c_flags |= IOG_GOING_DOWN) +#define clear_group_down(gp) ((gp)->c_flags &= ~IOG_GOING_DOWN) +#define is_group_down(gp) ((gp)->c_flags & IOG_GOING_DOWN) + +#define set_group_suspended(gp) ((gp)->c_flags |= IOG_SUSPENDED) +#define clear_group_suspended(gp) ((gp)->c_flags &= ~IOG_SUSPENDED) +#define is_group_suspended(gp) ((gp)->c_flags & IOG_SUSPENDED) + +#define set_prio_read(gp) ((gp)->c_flags |= IOG_PRIO_QUEUE) +#define clear_prio_read(gp) ((gp)->c_flags &= ~IOG_PRIO_QUEUE) +#define is_prio_read(gp) \ + ((gp)->c_flags & (IOG_PRIO_QUEUE|IOG_PRIO_BIO_WRITE) == IOG_PRIO_QUEUE) + +#define set_prio_write(gp) \ + ((gp)->c_flags |= (IOG_PRIO_QUEUE|IOG_PRIO_BIO_WRITE)) +#define clear_prio_write(gp) \ + ((gp)->c_flags &= ~(IOG_PRIO_QUEUE|IOG_PRIO_BIO_WRITE)) +#define is_prio_write(gp) \ + ((gp)->c_flags & (IOG_PRIO_QUEUE|IOG_PRIO_BIO_WRITE) == \ + (IOG_PRIO_QUEUE|IOG_PRIO_BIO_WRITE)) + +#define set_prio_queue(gp, direct) \ + ((gp)->c_flags |= (IOG_PRIO_QUEUE|direct)) +#define clear_prio_queue(gp) clear_prio_write(gp) +#define is_prio_queue(gp) ((gp)->c_flags & IOG_PRIO_QUEUE) +#define prio_queue_direct(gp) ((gp)->c_flags & IOG_PRIO_BIO_WRITE) + + +struct policy_type { + const char *p_name; + int (*p_policy_init)(struct ioband_device *, int, char **); +}; + +extern struct policy_type dm_ioband_policy_type[]; + +struct group_type { + const char *t_name; + int (*t_getid)(struct bio *); +}; + +extern struct group_type dm_ioband_group_type[]; + +/* Just for debugging */ +extern long ioband_debug; +#define dprintk(format, a...) \ + if (ioband_debug > 0) ioband_debug--, printk(format, ##a)
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