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block/blk-throttle.c
42.7 KB
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/* * 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> |
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#include <linux/blk-cgroup.h> |
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#include "blk.h" |
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/* 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 */ |
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static struct blkcg_policy blkcg_policy_throtl; |
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/* A workqueue to queue throttle related work */ static struct workqueue_struct *kthrotld_workqueue; |
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/* * To implement hierarchical throttling, throtl_grps form a tree and bios * are dispatched upwards level by level until they reach the top and get * issued. When dispatching bios from the children and local group at each * level, if the bios are dispatched into a single bio_list, there's a risk * of a local or child group which can queue many bios at once filling up * the list starving others. * * To avoid such starvation, dispatched bios are queued separately * according to where they came from. When they are again dispatched to * the parent, they're popped in round-robin order so that no single source * hogs the dispatch window. * * throtl_qnode is used to keep the queued bios separated by their sources. * Bios are queued to throtl_qnode which in turn is queued to * throtl_service_queue and then dispatched in round-robin order. * * It's also used to track the reference counts on blkg's. A qnode always * belongs to a throtl_grp and gets queued on itself or the parent, so * incrementing the reference of the associated throtl_grp when a qnode is * queued and decrementing when dequeued is enough to keep the whole blkg * tree pinned while bios are in flight. */ struct throtl_qnode { struct list_head node; /* service_queue->queued[] */ struct bio_list bios; /* queued bios */ struct throtl_grp *tg; /* tg this qnode belongs to */ }; |
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struct throtl_service_queue { |
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struct throtl_service_queue *parent_sq; /* the parent service_queue */ |
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/* * Bios queued directly to this service_queue or dispatched from * children throtl_grp's. */ |
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struct list_head queued[2]; /* throtl_qnode [READ/WRITE] */ |
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unsigned int nr_queued[2]; /* number of queued bios */ /* * RB tree of active children throtl_grp's, which are sorted by * their ->disptime. */ |
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struct rb_root pending_tree; /* RB tree of active tgs */ struct rb_node *first_pending; /* first node in the tree */ unsigned int nr_pending; /* # queued in the tree */ unsigned long first_pending_disptime; /* disptime of the first tg */ |
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struct timer_list pending_timer; /* fires on first_pending_disptime */ |
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}; |
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enum tg_state_flags { THROTL_TG_PENDING = 1 << 0, /* on parent's pending tree */ |
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THROTL_TG_WAS_EMPTY = 1 << 1, /* bio_lists[] became non-empty */ |
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}; |
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#define rb_entry_tg(node) rb_entry((node), struct throtl_grp, rb_node) struct throtl_grp { |
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/* must be the first member */ struct blkg_policy_data pd; |
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/* active throtl group service_queue member */ |
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struct rb_node rb_node; |
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/* throtl_data this group belongs to */ struct throtl_data *td; |
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/* this group's service queue */ struct throtl_service_queue service_queue; |
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/* |
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* qnode_on_self is used when bios are directly queued to this * throtl_grp so that local bios compete fairly with bios * dispatched from children. qnode_on_parent is used when bios are * dispatched from this throtl_grp into its parent and will compete * with the sibling qnode_on_parents and the parent's * qnode_on_self. */ struct throtl_qnode qnode_on_self[2]; struct throtl_qnode qnode_on_parent[2]; /* |
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* 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; |
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unsigned int flags; |
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/* are there any throtl rules between this group and td? */ bool has_rules[2]; |
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/* bytes per second rate limits */ uint64_t bps[2]; |
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/* IOPS limits */ unsigned int iops[2]; |
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/* Number of bytes disptached in current slice */ uint64_t bytes_disp[2]; |
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/* Number of bio's dispatched in current slice */ unsigned int io_disp[2]; |
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/* When did we start a new slice */ unsigned long slice_start[2]; unsigned long slice_end[2]; }; struct throtl_data { |
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/* service tree for active throtl groups */ |
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struct throtl_service_queue service_queue; |
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struct request_queue *queue; /* Total Number of queued bios on READ and WRITE lists */ unsigned int nr_queued[2]; |
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/* Work for dispatching throttled bios */ |
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struct work_struct dispatch_work; |
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}; |
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static void throtl_pending_timer_fn(unsigned long arg); |
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static inline struct throtl_grp *pd_to_tg(struct blkg_policy_data *pd) { return pd ? container_of(pd, struct throtl_grp, pd) : NULL; } |
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static inline struct throtl_grp *blkg_to_tg(struct blkcg_gq *blkg) |
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{ |
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return pd_to_tg(blkg_to_pd(blkg, &blkcg_policy_throtl)); |
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} |
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static inline struct blkcg_gq *tg_to_blkg(struct throtl_grp *tg) |
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{ |
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return pd_to_blkg(&tg->pd); |
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} |
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/** * sq_to_tg - return the throl_grp the specified service queue belongs to * @sq: the throtl_service_queue of interest * * Return the throtl_grp @sq belongs to. If @sq is the top-level one * embedded in throtl_data, %NULL is returned. */ static struct throtl_grp *sq_to_tg(struct throtl_service_queue *sq) { if (sq && sq->parent_sq) return container_of(sq, struct throtl_grp, service_queue); else return NULL; } /** * sq_to_td - return throtl_data the specified service queue belongs to * @sq: the throtl_service_queue of interest * * A service_queue can be embeded in either a throtl_grp or throtl_data. * Determine the associated throtl_data accordingly and return it. */ static struct throtl_data *sq_to_td(struct throtl_service_queue *sq) { struct throtl_grp *tg = sq_to_tg(sq); if (tg) return tg->td; else return container_of(sq, struct throtl_data, service_queue); } /** * throtl_log - log debug message via blktrace * @sq: the service_queue being reported * @fmt: printf format string * @args: printf args * * The messages are prefixed with "throtl BLKG_NAME" if @sq belongs to a * throtl_grp; otherwise, just "throtl". |
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*/ #define throtl_log(sq, fmt, args...) do { \ struct throtl_grp *__tg = sq_to_tg((sq)); \ struct throtl_data *__td = sq_to_td((sq)); \ \ (void)__td; \ |
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if (likely(!blk_trace_note_message_enabled(__td->queue))) \ break; \ |
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if ((__tg)) { \ char __pbuf[128]; \ |
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\ |
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blkg_path(tg_to_blkg(__tg), __pbuf, sizeof(__pbuf)); \ blk_add_trace_msg(__td->queue, "throtl %s " fmt, __pbuf, ##args); \ } else { \ blk_add_trace_msg(__td->queue, "throtl " fmt, ##args); \ } \ |
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} while (0) |
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static void throtl_qnode_init(struct throtl_qnode *qn, struct throtl_grp *tg) { INIT_LIST_HEAD(&qn->node); bio_list_init(&qn->bios); qn->tg = tg; } /** * throtl_qnode_add_bio - add a bio to a throtl_qnode and activate it * @bio: bio being added * @qn: qnode to add bio to * @queued: the service_queue->queued[] list @qn belongs to * * Add @bio to @qn and put @qn on @queued if it's not already on. * @qn->tg's reference count is bumped when @qn is activated. See the * comment on top of throtl_qnode definition for details. */ static void throtl_qnode_add_bio(struct bio *bio, struct throtl_qnode *qn, struct list_head *queued) { bio_list_add(&qn->bios, bio); if (list_empty(&qn->node)) { list_add_tail(&qn->node, queued); blkg_get(tg_to_blkg(qn->tg)); } } /** * throtl_peek_queued - peek the first bio on a qnode list * @queued: the qnode list to peek */ static struct bio *throtl_peek_queued(struct list_head *queued) { struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); struct bio *bio; if (list_empty(queued)) return NULL; bio = bio_list_peek(&qn->bios); WARN_ON_ONCE(!bio); return bio; } /** * throtl_pop_queued - pop the first bio form a qnode list * @queued: the qnode list to pop a bio from * @tg_to_put: optional out argument for throtl_grp to put * * Pop the first bio from the qnode list @queued. After popping, the first * qnode is removed from @queued if empty or moved to the end of @queued so * that the popping order is round-robin. * * When the first qnode is removed, its associated throtl_grp should be put * too. If @tg_to_put is NULL, this function automatically puts it; * otherwise, *@tg_to_put is set to the throtl_grp to put and the caller is * responsible for putting it. */ static struct bio *throtl_pop_queued(struct list_head *queued, struct throtl_grp **tg_to_put) { struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); struct bio *bio; if (list_empty(queued)) return NULL; bio = bio_list_pop(&qn->bios); WARN_ON_ONCE(!bio); if (bio_list_empty(&qn->bios)) { list_del_init(&qn->node); if (tg_to_put) *tg_to_put = qn->tg; else blkg_put(tg_to_blkg(qn->tg)); } else { list_move_tail(&qn->node, queued); } return bio; } |
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/* init a service_queue, assumes the caller zeroed it */ |
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static void throtl_service_queue_init(struct throtl_service_queue *sq) |
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{ |
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INIT_LIST_HEAD(&sq->queued[0]); INIT_LIST_HEAD(&sq->queued[1]); |
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sq->pending_tree = RB_ROOT; |
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setup_timer(&sq->pending_timer, throtl_pending_timer_fn, (unsigned long)sq); } |
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static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node) { |
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struct throtl_grp *tg; |
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int rw; |
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tg = kzalloc_node(sizeof(*tg), gfp, node); if (!tg) |
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return NULL; |
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throtl_service_queue_init(&tg->service_queue); for (rw = READ; rw <= WRITE; rw++) { throtl_qnode_init(&tg->qnode_on_self[rw], tg); throtl_qnode_init(&tg->qnode_on_parent[rw], tg); } RB_CLEAR_NODE(&tg->rb_node); tg->bps[READ] = -1; tg->bps[WRITE] = -1; tg->iops[READ] = -1; tg->iops[WRITE] = -1; |
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return &tg->pd; |
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} |
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static void throtl_pd_init(struct blkg_policy_data *pd) |
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{ |
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struct throtl_grp *tg = pd_to_tg(pd); struct blkcg_gq *blkg = tg_to_blkg(tg); |
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struct throtl_data *td = blkg->q->td; |
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struct throtl_service_queue *sq = &tg->service_queue; |
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|
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/* |
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* If on the default hierarchy, we switch to properly hierarchical |
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* behavior where limits on a given throtl_grp are applied to the * whole subtree rather than just the group itself. e.g. If 16M * read_bps limit is set on the root group, the whole system can't * exceed 16M for the device. * |
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* If not on the default hierarchy, the broken flat hierarchy |
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* behavior is retained where all throtl_grps are treated as if * they're all separate root groups right below throtl_data. * Limits of a group don't interact with limits of other groups * regardless of the position of the group in the hierarchy. */ |
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sq->parent_sq = &td->service_queue; |
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if (cgroup_subsys_on_dfl(io_cgrp_subsys) && blkg->parent) |
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sq->parent_sq = &blkg_to_tg(blkg->parent)->service_queue; |
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tg->td = td; |
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} |
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/* * Set has_rules[] if @tg or any of its parents have limits configured. * This doesn't require walking up to the top of the hierarchy as the * parent's has_rules[] is guaranteed to be correct. */ static void tg_update_has_rules(struct throtl_grp *tg) { struct throtl_grp *parent_tg = sq_to_tg(tg->service_queue.parent_sq); int rw; for (rw = READ; rw <= WRITE; rw++) tg->has_rules[rw] = (parent_tg && parent_tg->has_rules[rw]) || (tg->bps[rw] != -1 || tg->iops[rw] != -1); } |
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static void throtl_pd_online(struct blkg_policy_data *pd) |
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{ /* * We don't want new groups to escape the limits of its ancestors. * Update has_rules[] after a new group is brought online. */ |
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tg_update_has_rules(pd_to_tg(pd)); |
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} |
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static void throtl_pd_free(struct blkg_policy_data *pd) { |
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struct throtl_grp *tg = pd_to_tg(pd); |
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del_timer_sync(&tg->service_queue.pending_timer); |
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kfree(tg); |
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} |
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static struct throtl_grp * throtl_rb_first(struct throtl_service_queue *parent_sq) |
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{ /* Service tree is empty */ |
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if (!parent_sq->nr_pending) |
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return NULL; |
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if (!parent_sq->first_pending) parent_sq->first_pending = rb_first(&parent_sq->pending_tree); |
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|
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if (parent_sq->first_pending) return rb_entry_tg(parent_sq->first_pending); |
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return NULL; } static void rb_erase_init(struct rb_node *n, struct rb_root *root) { rb_erase(n, root); RB_CLEAR_NODE(n); } |
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static void throtl_rb_erase(struct rb_node *n, struct throtl_service_queue *parent_sq) |
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{ |
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if (parent_sq->first_pending == n) parent_sq->first_pending = NULL; rb_erase_init(n, &parent_sq->pending_tree); --parent_sq->nr_pending; |
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} |
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static void update_min_dispatch_time(struct throtl_service_queue *parent_sq) |
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{ struct throtl_grp *tg; |
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tg = throtl_rb_first(parent_sq); |
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if (!tg) return; |
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parent_sq->first_pending_disptime = tg->disptime; |
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} |
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static void tg_service_queue_add(struct throtl_grp *tg) |
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{ |
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struct throtl_service_queue *parent_sq = tg->service_queue.parent_sq; |
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struct rb_node **node = &parent_sq->pending_tree.rb_node; |
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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) |
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parent_sq->first_pending = &tg->rb_node; |
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rb_link_node(&tg->rb_node, parent, node); |
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rb_insert_color(&tg->rb_node, &parent_sq->pending_tree); |
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} |
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static void __throtl_enqueue_tg(struct throtl_grp *tg) |
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{ |
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tg_service_queue_add(tg); |
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tg->flags |= THROTL_TG_PENDING; |
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tg->service_queue.parent_sq->nr_pending++; |
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} |
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static void throtl_enqueue_tg(struct throtl_grp *tg) |
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{ |
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if (!(tg->flags & THROTL_TG_PENDING)) |
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__throtl_enqueue_tg(tg); |
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} |
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static void __throtl_dequeue_tg(struct throtl_grp *tg) |
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{ |
77216b048 blk-throttle: add... |
450 |
throtl_rb_erase(&tg->rb_node, tg->service_queue.parent_sq); |
5b2c16aae blk-throttle: sim... |
451 |
tg->flags &= ~THROTL_TG_PENDING; |
e43473b7f blkio: Core imple... |
452 |
} |
77216b048 blk-throttle: add... |
453 |
static void throtl_dequeue_tg(struct throtl_grp *tg) |
e43473b7f blkio: Core imple... |
454 |
{ |
5b2c16aae blk-throttle: sim... |
455 |
if (tg->flags & THROTL_TG_PENDING) |
77216b048 blk-throttle: add... |
456 |
__throtl_dequeue_tg(tg); |
e43473b7f blkio: Core imple... |
457 |
} |
a9131a27e blk-throttle: rel... |
458 |
/* Call with queue lock held */ |
69df0ab03 blk-throttle: sep... |
459 460 |
static void throtl_schedule_pending_timer(struct throtl_service_queue *sq, unsigned long expires) |
a9131a27e blk-throttle: rel... |
461 |
{ |
69df0ab03 blk-throttle: sep... |
462 463 464 |
mod_timer(&sq->pending_timer, expires); throtl_log(sq, "schedule timer. delay=%lu jiffies=%lu", expires - jiffies, jiffies); |
a9131a27e blk-throttle: rel... |
465 |
} |
7f52f98c2 blk-throttle: imp... |
466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 |
/** * throtl_schedule_next_dispatch - schedule the next dispatch cycle * @sq: the service_queue to schedule dispatch for * @force: force scheduling * * Arm @sq->pending_timer so that the next dispatch cycle starts on the * dispatch time of the first pending child. Returns %true if either timer * is armed or there's no pending child left. %false if the current * dispatch window is still open and the caller should continue * dispatching. * * If @force is %true, the dispatch timer is always scheduled and this * function is guaranteed to return %true. This is to be used when the * caller can't dispatch itself and needs to invoke pending_timer * unconditionally. Note that forced scheduling is likely to induce short * delay before dispatch starts even if @sq->first_pending_disptime is not * in the future and thus shouldn't be used in hot paths. */ static bool throtl_schedule_next_dispatch(struct throtl_service_queue *sq, bool force) |
e43473b7f blkio: Core imple... |
486 |
{ |
6a525600f blk-throttle: rem... |
487 |
/* any pending children left? */ |
c9e0332e8 blk-throttle: ren... |
488 |
if (!sq->nr_pending) |
7f52f98c2 blk-throttle: imp... |
489 |
return true; |
e43473b7f blkio: Core imple... |
490 |
|
c9e0332e8 blk-throttle: ren... |
491 |
update_min_dispatch_time(sq); |
e43473b7f blkio: Core imple... |
492 |
|
69df0ab03 blk-throttle: sep... |
493 |
/* is the next dispatch time in the future? */ |
7f52f98c2 blk-throttle: imp... |
494 |
if (force || time_after(sq->first_pending_disptime, jiffies)) { |
69df0ab03 blk-throttle: sep... |
495 |
throtl_schedule_pending_timer(sq, sq->first_pending_disptime); |
7f52f98c2 blk-throttle: imp... |
496 |
return true; |
69df0ab03 blk-throttle: sep... |
497 |
} |
7f52f98c2 blk-throttle: imp... |
498 499 |
/* tell the caller to continue dispatching */ return false; |
e43473b7f blkio: Core imple... |
500 |
} |
32ee5bc47 blk-throttle: Acc... |
501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 |
static inline void throtl_start_new_slice_with_credit(struct throtl_grp *tg, bool rw, unsigned long start) { tg->bytes_disp[rw] = 0; tg->io_disp[rw] = 0; /* * Previous slice has expired. We must have trimmed it after last * bio dispatch. That means since start of last slice, we never used * that bandwidth. Do try to make use of that bandwidth while giving * credit. */ if (time_after_eq(start, tg->slice_start[rw])) tg->slice_start[rw] = start; tg->slice_end[rw] = jiffies + throtl_slice; throtl_log(&tg->service_queue, "[%c] new slice with credit start=%lu end=%lu jiffies=%lu", rw == READ ? 'R' : 'W', tg->slice_start[rw], tg->slice_end[rw], jiffies); } |
0f3457f60 blk-throttle: add... |
522 |
static inline void throtl_start_new_slice(struct throtl_grp *tg, bool rw) |
e43473b7f blkio: Core imple... |
523 524 |
{ tg->bytes_disp[rw] = 0; |
8e89d13f4 blkio: Implementa... |
525 |
tg->io_disp[rw] = 0; |
e43473b7f blkio: Core imple... |
526 527 |
tg->slice_start[rw] = jiffies; tg->slice_end[rw] = jiffies + throtl_slice; |
fda6f272c blk-throttle: imp... |
528 529 530 531 |
throtl_log(&tg->service_queue, "[%c] new slice start=%lu end=%lu jiffies=%lu", rw == READ ? 'R' : 'W', tg->slice_start[rw], tg->slice_end[rw], jiffies); |
e43473b7f blkio: Core imple... |
532 |
} |
0f3457f60 blk-throttle: add... |
533 534 |
static inline void throtl_set_slice_end(struct throtl_grp *tg, bool rw, unsigned long jiffy_end) |
d1ae8ffdf blk-throttle: Tri... |
535 536 537 |
{ tg->slice_end[rw] = roundup(jiffy_end, throtl_slice); } |
0f3457f60 blk-throttle: add... |
538 539 |
static inline void throtl_extend_slice(struct throtl_grp *tg, bool rw, unsigned long jiffy_end) |
e43473b7f blkio: Core imple... |
540 541 |
{ tg->slice_end[rw] = roundup(jiffy_end, throtl_slice); |
fda6f272c blk-throttle: imp... |
542 543 544 545 |
throtl_log(&tg->service_queue, "[%c] extend slice start=%lu end=%lu jiffies=%lu", rw == READ ? 'R' : 'W', tg->slice_start[rw], tg->slice_end[rw], jiffies); |
e43473b7f blkio: Core imple... |
546 547 548 |
} /* Determine if previously allocated or extended slice is complete or not */ |
0f3457f60 blk-throttle: add... |
549 |
static bool throtl_slice_used(struct throtl_grp *tg, bool rw) |
e43473b7f blkio: Core imple... |
550 551 |
{ if (time_in_range(jiffies, tg->slice_start[rw], tg->slice_end[rw])) |
5cf8c2277 block/blk-throttl... |
552 |
return false; |
e43473b7f blkio: Core imple... |
553 554 555 556 557 |
return 1; } /* Trim the used slices and adjust slice start accordingly */ |
0f3457f60 blk-throttle: add... |
558 |
static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw) |
e43473b7f blkio: Core imple... |
559 |
{ |
3aad5d3ee blkio-throttle: F... |
560 561 |
unsigned long nr_slices, time_elapsed, io_trim; u64 bytes_trim, tmp; |
e43473b7f blkio: Core imple... |
562 563 564 565 566 567 568 569 |
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. */ |
0f3457f60 blk-throttle: add... |
570 |
if (throtl_slice_used(tg, rw)) |
e43473b7f blkio: Core imple... |
571 |
return; |
d1ae8ffdf blk-throttle: Tri... |
572 573 574 575 576 577 578 |
/* * A bio has been dispatched. Also adjust slice_end. It might happen * that initially cgroup limit was very low resulting in high * slice_end, but later limit was bumped up and bio was dispached * sooner, then we need to reduce slice_end. A high bogus slice_end * is bad because it does not allow new slice to start. */ |
0f3457f60 blk-throttle: add... |
579 |
throtl_set_slice_end(tg, rw, jiffies + throtl_slice); |
d1ae8ffdf blk-throttle: Tri... |
580 |
|
e43473b7f blkio: Core imple... |
581 582 583 584 585 586 |
time_elapsed = jiffies - tg->slice_start[rw]; nr_slices = time_elapsed / throtl_slice; if (!nr_slices) return; |
3aad5d3ee blkio-throttle: F... |
587 588 589 |
tmp = tg->bps[rw] * throtl_slice * nr_slices; do_div(tmp, HZ); bytes_trim = tmp; |
e43473b7f blkio: Core imple... |
590 |
|
8e89d13f4 blkio: Implementa... |
591 |
io_trim = (tg->iops[rw] * throtl_slice * nr_slices)/HZ; |
e43473b7f blkio: Core imple... |
592 |
|
8e89d13f4 blkio: Implementa... |
593 |
if (!bytes_trim && !io_trim) |
e43473b7f blkio: Core imple... |
594 595 596 597 598 599 |
return; if (tg->bytes_disp[rw] >= bytes_trim) tg->bytes_disp[rw] -= bytes_trim; else tg->bytes_disp[rw] = 0; |
8e89d13f4 blkio: Implementa... |
600 601 602 603 |
if (tg->io_disp[rw] >= io_trim) tg->io_disp[rw] -= io_trim; else tg->io_disp[rw] = 0; |
e43473b7f blkio: Core imple... |
604 |
tg->slice_start[rw] += nr_slices * throtl_slice; |
fda6f272c blk-throttle: imp... |
605 606 607 608 |
throtl_log(&tg->service_queue, "[%c] trim slice nr=%lu bytes=%llu io=%lu start=%lu end=%lu jiffies=%lu", rw == READ ? 'R' : 'W', nr_slices, bytes_trim, io_trim, tg->slice_start[rw], tg->slice_end[rw], jiffies); |
e43473b7f blkio: Core imple... |
609 |
} |
0f3457f60 blk-throttle: add... |
610 611 |
static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio, unsigned long *wait) |
e43473b7f blkio: Core imple... |
612 613 |
{ bool rw = bio_data_dir(bio); |
8e89d13f4 blkio: Implementa... |
614 |
unsigned int io_allowed; |
e43473b7f blkio: Core imple... |
615 |
unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd; |
c49c06e49 blkio-throttle: F... |
616 |
u64 tmp; |
e43473b7f blkio: Core imple... |
617 |
|
8e89d13f4 blkio: Implementa... |
618 |
jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw]; |
e43473b7f blkio: Core imple... |
619 |
|
8e89d13f4 blkio: Implementa... |
620 621 622 623 624 |
/* 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); |
c49c06e49 blkio-throttle: F... |
625 626 627 628 629 630 631 632 633 634 635 636 637 638 |
/* * jiffy_elapsed_rnd should not be a big value as minimum iops can be * 1 then at max jiffy elapsed should be equivalent of 1 second as we * will allow dispatch after 1 second and after that slice should * have been trimmed. */ tmp = (u64)tg->iops[rw] * jiffy_elapsed_rnd; do_div(tmp, HZ); if (tmp > UINT_MAX) io_allowed = UINT_MAX; else io_allowed = tmp; |
8e89d13f4 blkio: Implementa... |
639 640 |
if (tg->io_disp[rw] + 1 <= io_allowed) { |
e43473b7f blkio: Core imple... |
641 642 |
if (wait) *wait = 0; |
5cf8c2277 block/blk-throttl... |
643 |
return true; |
e43473b7f blkio: Core imple... |
644 |
} |
8e89d13f4 blkio: Implementa... |
645 646 647 648 649 650 651 652 653 654 655 656 |
/* 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; } |
0f3457f60 blk-throttle: add... |
657 658 |
static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio, unsigned long *wait) |
8e89d13f4 blkio: Implementa... |
659 660 |
{ bool rw = bio_data_dir(bio); |
3aad5d3ee blkio-throttle: F... |
661 |
u64 bytes_allowed, extra_bytes, tmp; |
8e89d13f4 blkio: Implementa... |
662 |
unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd; |
e43473b7f blkio: Core imple... |
663 664 665 666 667 668 669 670 |
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); |
5e901a2b9 blkio-throttle: T... |
671 672 |
tmp = tg->bps[rw] * jiffy_elapsed_rnd; do_div(tmp, HZ); |
3aad5d3ee blkio-throttle: F... |
673 |
bytes_allowed = tmp; |
e43473b7f blkio: Core imple... |
674 |
|
4f024f379 block: Abstract o... |
675 |
if (tg->bytes_disp[rw] + bio->bi_iter.bi_size <= bytes_allowed) { |
e43473b7f blkio: Core imple... |
676 677 |
if (wait) *wait = 0; |
5cf8c2277 block/blk-throttl... |
678 |
return true; |
e43473b7f blkio: Core imple... |
679 680 681 |
} /* Calc approx time to dispatch */ |
4f024f379 block: Abstract o... |
682 |
extra_bytes = tg->bytes_disp[rw] + bio->bi_iter.bi_size - bytes_allowed; |
e43473b7f blkio: Core imple... |
683 684 685 686 687 688 689 690 691 692 |
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); |
e43473b7f blkio: Core imple... |
693 694 |
if (wait) *wait = jiffy_wait; |
8e89d13f4 blkio: Implementa... |
695 696 697 698 699 700 701 |
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 */ |
0f3457f60 blk-throttle: add... |
702 703 |
static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio, unsigned long *wait) |
8e89d13f4 blkio: Implementa... |
704 705 706 707 708 709 710 711 712 713 |
{ 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. */ |
73f0d49a9 blk-throttle: mov... |
714 |
BUG_ON(tg->service_queue.nr_queued[rw] && |
c5cc2070b blk-throttle: add... |
715 |
bio != throtl_peek_queued(&tg->service_queue.queued[rw])); |
e43473b7f blkio: Core imple... |
716 |
|
8e89d13f4 blkio: Implementa... |
717 718 719 720 |
/* If tg->bps = -1, then BW is unlimited */ if (tg->bps[rw] == -1 && tg->iops[rw] == -1) { if (wait) *wait = 0; |
5cf8c2277 block/blk-throttl... |
721 |
return true; |
8e89d13f4 blkio: Implementa... |
722 723 724 725 726 |
} /* * If previous slice expired, start a new one otherwise renew/extend * existing slice to make sure it is at least throtl_slice interval |
164c80ed8 blk-throttle: Ext... |
727 728 729 |
* long since now. New slice is started only for empty throttle group. * If there is queued bio, that means there should be an active * slice and it should be extended instead. |
8e89d13f4 blkio: Implementa... |
730 |
*/ |
164c80ed8 blk-throttle: Ext... |
731 |
if (throtl_slice_used(tg, rw) && !(tg->service_queue.nr_queued[rw])) |
0f3457f60 blk-throttle: add... |
732 |
throtl_start_new_slice(tg, rw); |
8e89d13f4 blkio: Implementa... |
733 734 |
else { if (time_before(tg->slice_end[rw], jiffies + throtl_slice)) |
0f3457f60 blk-throttle: add... |
735 |
throtl_extend_slice(tg, rw, jiffies + throtl_slice); |
8e89d13f4 blkio: Implementa... |
736 |
} |
0f3457f60 blk-throttle: add... |
737 738 |
if (tg_with_in_bps_limit(tg, bio, &bps_wait) && tg_with_in_iops_limit(tg, bio, &iops_wait)) { |
8e89d13f4 blkio: Implementa... |
739 740 741 742 743 744 745 746 747 748 749 |
if (wait) *wait = 0; return 1; } max_wait = max(bps_wait, iops_wait); if (wait) *wait = max_wait; if (time_before(tg->slice_end[rw], jiffies + max_wait)) |
0f3457f60 blk-throttle: add... |
750 |
throtl_extend_slice(tg, rw, jiffies + max_wait); |
e43473b7f blkio: Core imple... |
751 752 753 754 755 756 757 |
return 0; } static void throtl_charge_bio(struct throtl_grp *tg, struct bio *bio) { bool rw = bio_data_dir(bio); |
e43473b7f blkio: Core imple... |
758 759 |
/* Charge the bio to the group */ |
4f024f379 block: Abstract o... |
760 |
tg->bytes_disp[rw] += bio->bi_iter.bi_size; |
8e89d13f4 blkio: Implementa... |
761 |
tg->io_disp[rw]++; |
e43473b7f blkio: Core imple... |
762 |
|
2a0f61e6e blk-throttle: set... |
763 764 765 766 767 |
/* * REQ_THROTTLED is used to prevent the same bio to be throttled * more than once as a throttled bio will go through blk-throtl the * second time when it eventually gets issued. Set it when a bio * is being charged to a tg. |
2a0f61e6e blk-throttle: set... |
768 |
*/ |
1eff9d322 block: rename bio... |
769 770 |
if (!(bio->bi_opf & REQ_THROTTLED)) bio->bi_opf |= REQ_THROTTLED; |
e43473b7f blkio: Core imple... |
771 |
} |
c5cc2070b blk-throttle: add... |
772 773 774 775 776 777 778 779 780 781 782 |
/** * throtl_add_bio_tg - add a bio to the specified throtl_grp * @bio: bio to add * @qn: qnode to use * @tg: the target throtl_grp * * Add @bio to @tg's service_queue using @qn. If @qn is not specified, * tg->qnode_on_self[] is used. */ static void throtl_add_bio_tg(struct bio *bio, struct throtl_qnode *qn, struct throtl_grp *tg) |
e43473b7f blkio: Core imple... |
783 |
{ |
73f0d49a9 blk-throttle: mov... |
784 |
struct throtl_service_queue *sq = &tg->service_queue; |
e43473b7f blkio: Core imple... |
785 |
bool rw = bio_data_dir(bio); |
c5cc2070b blk-throttle: add... |
786 787 |
if (!qn) qn = &tg->qnode_on_self[rw]; |
0e9f4164b blk-throttle: gen... |
788 789 790 791 792 793 794 795 |
/* * If @tg doesn't currently have any bios queued in the same * direction, queueing @bio can change when @tg should be * dispatched. Mark that @tg was empty. This is automatically * cleaered on the next tg_update_disptime(). */ if (!sq->nr_queued[rw]) tg->flags |= THROTL_TG_WAS_EMPTY; |
c5cc2070b blk-throttle: add... |
796 |
throtl_qnode_add_bio(bio, qn, &sq->queued[rw]); |
73f0d49a9 blk-throttle: mov... |
797 |
sq->nr_queued[rw]++; |
77216b048 blk-throttle: add... |
798 |
throtl_enqueue_tg(tg); |
e43473b7f blkio: Core imple... |
799 |
} |
77216b048 blk-throttle: add... |
800 |
static void tg_update_disptime(struct throtl_grp *tg) |
e43473b7f blkio: Core imple... |
801 |
{ |
73f0d49a9 blk-throttle: mov... |
802 |
struct throtl_service_queue *sq = &tg->service_queue; |
e43473b7f blkio: Core imple... |
803 804 |
unsigned long read_wait = -1, write_wait = -1, min_wait = -1, disptime; struct bio *bio; |
c5cc2070b blk-throttle: add... |
805 |
if ((bio = throtl_peek_queued(&sq->queued[READ]))) |
0f3457f60 blk-throttle: add... |
806 |
tg_may_dispatch(tg, bio, &read_wait); |
e43473b7f blkio: Core imple... |
807 |
|
c5cc2070b blk-throttle: add... |
808 |
if ((bio = throtl_peek_queued(&sq->queued[WRITE]))) |
0f3457f60 blk-throttle: add... |
809 |
tg_may_dispatch(tg, bio, &write_wait); |
e43473b7f blkio: Core imple... |
810 811 812 |
min_wait = min(read_wait, write_wait); disptime = jiffies + min_wait; |
e43473b7f blkio: Core imple... |
813 |
/* Update dispatch time */ |
77216b048 blk-throttle: add... |
814 |
throtl_dequeue_tg(tg); |
e43473b7f blkio: Core imple... |
815 |
tg->disptime = disptime; |
77216b048 blk-throttle: add... |
816 |
throtl_enqueue_tg(tg); |
0e9f4164b blk-throttle: gen... |
817 818 819 |
/* see throtl_add_bio_tg() */ tg->flags &= ~THROTL_TG_WAS_EMPTY; |
e43473b7f blkio: Core imple... |
820 |
} |
32ee5bc47 blk-throttle: Acc... |
821 822 823 824 825 826 827 828 829 |
static void start_parent_slice_with_credit(struct throtl_grp *child_tg, struct throtl_grp *parent_tg, bool rw) { if (throtl_slice_used(parent_tg, rw)) { throtl_start_new_slice_with_credit(parent_tg, rw, child_tg->slice_start[rw]); } } |
77216b048 blk-throttle: add... |
830 |
static void tg_dispatch_one_bio(struct throtl_grp *tg, bool rw) |
e43473b7f blkio: Core imple... |
831 |
{ |
73f0d49a9 blk-throttle: mov... |
832 |
struct throtl_service_queue *sq = &tg->service_queue; |
6bc9c2b46 blk-throttle: mak... |
833 834 |
struct throtl_service_queue *parent_sq = sq->parent_sq; struct throtl_grp *parent_tg = sq_to_tg(parent_sq); |
c5cc2070b blk-throttle: add... |
835 |
struct throtl_grp *tg_to_put = NULL; |
e43473b7f blkio: Core imple... |
836 |
struct bio *bio; |
c5cc2070b blk-throttle: add... |
837 838 839 840 841 842 843 |
/* * @bio is being transferred from @tg to @parent_sq. Popping a bio * from @tg may put its reference and @parent_sq might end up * getting released prematurely. Remember the tg to put and put it * after @bio is transferred to @parent_sq. */ bio = throtl_pop_queued(&sq->queued[rw], &tg_to_put); |
73f0d49a9 blk-throttle: mov... |
844 |
sq->nr_queued[rw]--; |
e43473b7f blkio: Core imple... |
845 846 |
throtl_charge_bio(tg, bio); |
6bc9c2b46 blk-throttle: mak... |
847 848 849 850 851 852 853 854 855 |
/* * If our parent is another tg, we just need to transfer @bio to * the parent using throtl_add_bio_tg(). If our parent is * @td->service_queue, @bio is ready to be issued. Put it on its * bio_lists[] and decrease total number queued. The caller is * responsible for issuing these bios. */ if (parent_tg) { |
c5cc2070b blk-throttle: add... |
856 |
throtl_add_bio_tg(bio, &tg->qnode_on_parent[rw], parent_tg); |
32ee5bc47 blk-throttle: Acc... |
857 |
start_parent_slice_with_credit(tg, parent_tg, rw); |
6bc9c2b46 blk-throttle: mak... |
858 |
} else { |
c5cc2070b blk-throttle: add... |
859 860 |
throtl_qnode_add_bio(bio, &tg->qnode_on_parent[rw], &parent_sq->queued[rw]); |
6bc9c2b46 blk-throttle: mak... |
861 862 863 |
BUG_ON(tg->td->nr_queued[rw] <= 0); tg->td->nr_queued[rw]--; } |
e43473b7f blkio: Core imple... |
864 |
|
0f3457f60 blk-throttle: add... |
865 |
throtl_trim_slice(tg, rw); |
6bc9c2b46 blk-throttle: mak... |
866 |
|
c5cc2070b blk-throttle: add... |
867 868 |
if (tg_to_put) blkg_put(tg_to_blkg(tg_to_put)); |
e43473b7f blkio: Core imple... |
869 |
} |
77216b048 blk-throttle: add... |
870 |
static int throtl_dispatch_tg(struct throtl_grp *tg) |
e43473b7f blkio: Core imple... |
871 |
{ |
73f0d49a9 blk-throttle: mov... |
872 |
struct throtl_service_queue *sq = &tg->service_queue; |
e43473b7f blkio: Core imple... |
873 874 |
unsigned int nr_reads = 0, nr_writes = 0; unsigned int max_nr_reads = throtl_grp_quantum*3/4; |
c2f6805d4 blk-throttle: Fix... |
875 |
unsigned int max_nr_writes = throtl_grp_quantum - max_nr_reads; |
e43473b7f blkio: Core imple... |
876 877 878 |
struct bio *bio; /* Try to dispatch 75% READS and 25% WRITES */ |
c5cc2070b blk-throttle: add... |
879 |
while ((bio = throtl_peek_queued(&sq->queued[READ])) && |
0f3457f60 blk-throttle: add... |
880 |
tg_may_dispatch(tg, bio, NULL)) { |
e43473b7f blkio: Core imple... |
881 |
|
77216b048 blk-throttle: add... |
882 |
tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
e43473b7f blkio: Core imple... |
883 884 885 886 887 |
nr_reads++; if (nr_reads >= max_nr_reads) break; } |
c5cc2070b blk-throttle: add... |
888 |
while ((bio = throtl_peek_queued(&sq->queued[WRITE])) && |
0f3457f60 blk-throttle: add... |
889 |
tg_may_dispatch(tg, bio, NULL)) { |
e43473b7f blkio: Core imple... |
890 |
|
77216b048 blk-throttle: add... |
891 |
tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
e43473b7f blkio: Core imple... |
892 893 894 895 896 897 898 899 |
nr_writes++; if (nr_writes >= max_nr_writes) break; } return nr_reads + nr_writes; } |
651930bc1 blk-throttle: dis... |
900 |
static int throtl_select_dispatch(struct throtl_service_queue *parent_sq) |
e43473b7f blkio: Core imple... |
901 902 |
{ unsigned int nr_disp = 0; |
e43473b7f blkio: Core imple... |
903 904 |
while (1) { |
73f0d49a9 blk-throttle: mov... |
905 906 |
struct throtl_grp *tg = throtl_rb_first(parent_sq); struct throtl_service_queue *sq = &tg->service_queue; |
e43473b7f blkio: Core imple... |
907 908 909 910 911 912 |
if (!tg) break; if (time_before(jiffies, tg->disptime)) break; |
77216b048 blk-throttle: add... |
913 |
throtl_dequeue_tg(tg); |
e43473b7f blkio: Core imple... |
914 |
|
77216b048 blk-throttle: add... |
915 |
nr_disp += throtl_dispatch_tg(tg); |
e43473b7f blkio: Core imple... |
916 |
|
73f0d49a9 blk-throttle: mov... |
917 |
if (sq->nr_queued[0] || sq->nr_queued[1]) |
77216b048 blk-throttle: add... |
918 |
tg_update_disptime(tg); |
e43473b7f blkio: Core imple... |
919 920 921 922 923 924 925 |
if (nr_disp >= throtl_quantum) break; } return nr_disp; } |
6e1a5704c blk-throttle: dis... |
926 927 928 929 930 931 932 |
/** * throtl_pending_timer_fn - timer function for service_queue->pending_timer * @arg: the throtl_service_queue being serviced * * This timer is armed when a child throtl_grp with active bio's become * pending and queued on the service_queue's pending_tree and expires when * the first child throtl_grp should be dispatched. This function |
2e48a530a blk-throttle: mak... |
933 934 935 936 937 938 939 |
* dispatches bio's from the children throtl_grps to the parent * service_queue. * * If the parent's parent is another throtl_grp, dispatching is propagated * by either arming its pending_timer or repeating dispatch directly. If * the top-level service_tree is reached, throtl_data->dispatch_work is * kicked so that the ready bio's are issued. |
6e1a5704c blk-throttle: dis... |
940 |
*/ |
69df0ab03 blk-throttle: sep... |
941 942 943 |
static void throtl_pending_timer_fn(unsigned long arg) { struct throtl_service_queue *sq = (void *)arg; |
2e48a530a blk-throttle: mak... |
944 |
struct throtl_grp *tg = sq_to_tg(sq); |
69df0ab03 blk-throttle: sep... |
945 |
struct throtl_data *td = sq_to_td(sq); |
cb76199c3 blk-throttle: col... |
946 |
struct request_queue *q = td->queue; |
2e48a530a blk-throttle: mak... |
947 948 |
struct throtl_service_queue *parent_sq; bool dispatched; |
6e1a5704c blk-throttle: dis... |
949 |
int ret; |
e43473b7f blkio: Core imple... |
950 951 |
spin_lock_irq(q->queue_lock); |
2e48a530a blk-throttle: mak... |
952 953 954 |
again: parent_sq = sq->parent_sq; dispatched = false; |
e43473b7f blkio: Core imple... |
955 |
|
7f52f98c2 blk-throttle: imp... |
956 957 |
while (true) { throtl_log(sq, "dispatch nr_queued=%u read=%u write=%u", |
2e48a530a blk-throttle: mak... |
958 959 |
sq->nr_queued[READ] + sq->nr_queued[WRITE], sq->nr_queued[READ], sq->nr_queued[WRITE]); |
7f52f98c2 blk-throttle: imp... |
960 961 962 |
ret = throtl_select_dispatch(sq); if (ret) { |
7f52f98c2 blk-throttle: imp... |
963 964 965 |
throtl_log(sq, "bios disp=%u", ret); dispatched = true; } |
e43473b7f blkio: Core imple... |
966 |
|
7f52f98c2 blk-throttle: imp... |
967 968 |
if (throtl_schedule_next_dispatch(sq, false)) break; |
e43473b7f blkio: Core imple... |
969 |
|
7f52f98c2 blk-throttle: imp... |
970 971 972 973 |
/* this dispatch windows is still open, relax and repeat */ spin_unlock_irq(q->queue_lock); cpu_relax(); spin_lock_irq(q->queue_lock); |
651930bc1 blk-throttle: dis... |
974 |
} |
e43473b7f blkio: Core imple... |
975 |
|
2e48a530a blk-throttle: mak... |
976 977 |
if (!dispatched) goto out_unlock; |
6e1a5704c blk-throttle: dis... |
978 |
|
2e48a530a blk-throttle: mak... |
979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 |
if (parent_sq) { /* @parent_sq is another throl_grp, propagate dispatch */ if (tg->flags & THROTL_TG_WAS_EMPTY) { tg_update_disptime(tg); if (!throtl_schedule_next_dispatch(parent_sq, false)) { /* window is already open, repeat dispatching */ sq = parent_sq; tg = sq_to_tg(sq); goto again; } } } else { /* reached the top-level, queue issueing */ queue_work(kthrotld_workqueue, &td->dispatch_work); } out_unlock: |
e43473b7f blkio: Core imple... |
995 |
spin_unlock_irq(q->queue_lock); |
6e1a5704c blk-throttle: dis... |
996 |
} |
e43473b7f blkio: Core imple... |
997 |
|
6e1a5704c blk-throttle: dis... |
998 999 1000 1001 1002 1003 1004 1005 |
/** * blk_throtl_dispatch_work_fn - work function for throtl_data->dispatch_work * @work: work item being executed * * This function is queued for execution when bio's reach the bio_lists[] * of throtl_data->service_queue. Those bio's are ready and issued by this * function. */ |
8876e140e block/blk-throttl... |
1006 |
static void blk_throtl_dispatch_work_fn(struct work_struct *work) |
6e1a5704c blk-throttle: dis... |
1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 |
{ struct throtl_data *td = container_of(work, struct throtl_data, dispatch_work); struct throtl_service_queue *td_sq = &td->service_queue; struct request_queue *q = td->queue; struct bio_list bio_list_on_stack; struct bio *bio; struct blk_plug plug; int rw; bio_list_init(&bio_list_on_stack); spin_lock_irq(q->queue_lock); |
c5cc2070b blk-throttle: add... |
1020 1021 1022 |
for (rw = READ; rw <= WRITE; rw++) while ((bio = throtl_pop_queued(&td_sq->queued[rw], NULL))) bio_list_add(&bio_list_on_stack, bio); |
6e1a5704c blk-throttle: dis... |
1023 1024 1025 |
spin_unlock_irq(q->queue_lock); if (!bio_list_empty(&bio_list_on_stack)) { |
69d60eb96 blk-throttle: Use... |
1026 |
blk_start_plug(&plug); |
e43473b7f blkio: Core imple... |
1027 1028 |
while((bio = bio_list_pop(&bio_list_on_stack))) generic_make_request(bio); |
69d60eb96 blk-throttle: Use... |
1029 |
blk_finish_plug(&plug); |
e43473b7f blkio: Core imple... |
1030 |
} |
e43473b7f blkio: Core imple... |
1031 |
} |
f95a04afa blkcg: embed stru... |
1032 1033 |
static u64 tg_prfill_conf_u64(struct seq_file *sf, struct blkg_policy_data *pd, int off) |
60c2bc2d5 blkcg: move conf/... |
1034 |
{ |
f95a04afa blkcg: embed stru... |
1035 1036 |
struct throtl_grp *tg = pd_to_tg(pd); u64 v = *(u64 *)((void *)tg + off); |
60c2bc2d5 blkcg: move conf/... |
1037 |
|
af133ceb2 blkcg: move blkio... |
1038 |
if (v == -1) |
60c2bc2d5 blkcg: move conf/... |
1039 |
return 0; |
f95a04afa blkcg: embed stru... |
1040 |
return __blkg_prfill_u64(sf, pd, v); |
60c2bc2d5 blkcg: move conf/... |
1041 |
} |
f95a04afa blkcg: embed stru... |
1042 1043 |
static u64 tg_prfill_conf_uint(struct seq_file *sf, struct blkg_policy_data *pd, int off) |
e43473b7f blkio: Core imple... |
1044 |
{ |
f95a04afa blkcg: embed stru... |
1045 1046 |
struct throtl_grp *tg = pd_to_tg(pd); unsigned int v = *(unsigned int *)((void *)tg + off); |
fe0714377 blkio: Recalculat... |
1047 |
|
af133ceb2 blkcg: move blkio... |
1048 1049 |
if (v == -1) return 0; |
f95a04afa blkcg: embed stru... |
1050 |
return __blkg_prfill_u64(sf, pd, v); |
e43473b7f blkio: Core imple... |
1051 |
} |
2da8ca822 cgroup: replace c... |
1052 |
static int tg_print_conf_u64(struct seq_file *sf, void *v) |
8e89d13f4 blkio: Implementa... |
1053 |
{ |
2da8ca822 cgroup: replace c... |
1054 1055 |
blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_conf_u64, &blkcg_policy_throtl, seq_cft(sf)->private, false); |
af133ceb2 blkcg: move blkio... |
1056 |
return 0; |
8e89d13f4 blkio: Implementa... |
1057 |
} |
2da8ca822 cgroup: replace c... |
1058 |
static int tg_print_conf_uint(struct seq_file *sf, void *v) |
8e89d13f4 blkio: Implementa... |
1059 |
{ |
2da8ca822 cgroup: replace c... |
1060 1061 |
blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_conf_uint, &blkcg_policy_throtl, seq_cft(sf)->private, false); |
af133ceb2 blkcg: move blkio... |
1062 |
return 0; |
60c2bc2d5 blkcg: move conf/... |
1063 |
} |
69948b070 blkcg: separate o... |
1064 |
static void tg_conf_updated(struct throtl_grp *tg) |
60c2bc2d5 blkcg: move conf/... |
1065 |
{ |
69948b070 blkcg: separate o... |
1066 |
struct throtl_service_queue *sq = &tg->service_queue; |
492eb21b9 cgroup: make hier... |
1067 |
struct cgroup_subsys_state *pos_css; |
69948b070 blkcg: separate o... |
1068 |
struct blkcg_gq *blkg; |
af133ceb2 blkcg: move blkio... |
1069 |
|
fda6f272c blk-throttle: imp... |
1070 1071 1072 1073 |
throtl_log(&tg->service_queue, "limit change rbps=%llu wbps=%llu riops=%u wiops=%u", tg->bps[READ], tg->bps[WRITE], tg->iops[READ], tg->iops[WRITE]); |
632b44935 blk-throttle: rem... |
1074 1075 |
/* |
693e751e7 blk-throttle: imp... |
1076 1077 1078 1079 1080 1081 |
* Update has_rules[] flags for the updated tg's subtree. A tg is * considered to have rules if either the tg itself or any of its * ancestors has rules. This identifies groups without any * restrictions in the whole hierarchy and allows them to bypass * blk-throttle. */ |
69948b070 blkcg: separate o... |
1082 |
blkg_for_each_descendant_pre(blkg, pos_css, tg_to_blkg(tg)) |
693e751e7 blk-throttle: imp... |
1083 1084 1085 |
tg_update_has_rules(blkg_to_tg(blkg)); /* |
632b44935 blk-throttle: rem... |
1086 1087 1088 1089 1090 1091 1092 |
* We're already holding queue_lock and know @tg is valid. Let's * apply the new config directly. * * Restart the slices for both READ and WRITES. It might happen * that a group's limit are dropped suddenly and we don't want to * account recently dispatched IO with new low rate. */ |
0f3457f60 blk-throttle: add... |
1093 1094 |
throtl_start_new_slice(tg, 0); throtl_start_new_slice(tg, 1); |
632b44935 blk-throttle: rem... |
1095 |
|
5b2c16aae blk-throttle: sim... |
1096 |
if (tg->flags & THROTL_TG_PENDING) { |
77216b048 blk-throttle: add... |
1097 |
tg_update_disptime(tg); |
7f52f98c2 blk-throttle: imp... |
1098 |
throtl_schedule_next_dispatch(sq->parent_sq, true); |
632b44935 blk-throttle: rem... |
1099 |
} |
69948b070 blkcg: separate o... |
1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 |
} static ssize_t tg_set_conf(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off, bool is_u64) { struct blkcg *blkcg = css_to_blkcg(of_css(of)); struct blkg_conf_ctx ctx; struct throtl_grp *tg; int ret; u64 v; ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx); if (ret) return ret; ret = -EINVAL; if (sscanf(ctx.body, "%llu", &v) != 1) goto out_finish; if (!v) v = -1; tg = blkg_to_tg(ctx.blkg); if (is_u64) *(u64 *)((void *)tg + of_cft(of)->private) = v; else *(unsigned int *)((void *)tg + of_cft(of)->private) = v; |
60c2bc2d5 blkcg: move conf/... |
1127 |
|
69948b070 blkcg: separate o... |
1128 |
tg_conf_updated(tg); |
36aa9e5f5 blkcg: move body ... |
1129 1130 |
ret = 0; out_finish: |
60c2bc2d5 blkcg: move conf/... |
1131 |
blkg_conf_finish(&ctx); |
36aa9e5f5 blkcg: move body ... |
1132 |
return ret ?: nbytes; |
8e89d13f4 blkio: Implementa... |
1133 |
} |
451af504d cgroup: replace c... |
1134 1135 |
static ssize_t tg_set_conf_u64(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) |
60c2bc2d5 blkcg: move conf/... |
1136 |
{ |
451af504d cgroup: replace c... |
1137 |
return tg_set_conf(of, buf, nbytes, off, true); |
60c2bc2d5 blkcg: move conf/... |
1138 |
} |
451af504d cgroup: replace c... |
1139 1140 |
static ssize_t tg_set_conf_uint(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) |
60c2bc2d5 blkcg: move conf/... |
1141 |
{ |
451af504d cgroup: replace c... |
1142 |
return tg_set_conf(of, buf, nbytes, off, false); |
60c2bc2d5 blkcg: move conf/... |
1143 |
} |
880f50e22 blkcg: mark exist... |
1144 |
static struct cftype throtl_legacy_files[] = { |
60c2bc2d5 blkcg: move conf/... |
1145 1146 |
{ .name = "throttle.read_bps_device", |
af133ceb2 blkcg: move blkio... |
1147 |
.private = offsetof(struct throtl_grp, bps[READ]), |
2da8ca822 cgroup: replace c... |
1148 |
.seq_show = tg_print_conf_u64, |
451af504d cgroup: replace c... |
1149 |
.write = tg_set_conf_u64, |
60c2bc2d5 blkcg: move conf/... |
1150 1151 1152 |
}, { .name = "throttle.write_bps_device", |
af133ceb2 blkcg: move blkio... |
1153 |
.private = offsetof(struct throtl_grp, bps[WRITE]), |
2da8ca822 cgroup: replace c... |
1154 |
.seq_show = tg_print_conf_u64, |
451af504d cgroup: replace c... |
1155 |
.write = tg_set_conf_u64, |
60c2bc2d5 blkcg: move conf/... |
1156 1157 1158 |
}, { .name = "throttle.read_iops_device", |
af133ceb2 blkcg: move blkio... |
1159 |
.private = offsetof(struct throtl_grp, iops[READ]), |
2da8ca822 cgroup: replace c... |
1160 |
.seq_show = tg_print_conf_uint, |
451af504d cgroup: replace c... |
1161 |
.write = tg_set_conf_uint, |
60c2bc2d5 blkcg: move conf/... |
1162 1163 1164 |
}, { .name = "throttle.write_iops_device", |
af133ceb2 blkcg: move blkio... |
1165 |
.private = offsetof(struct throtl_grp, iops[WRITE]), |
2da8ca822 cgroup: replace c... |
1166 |
.seq_show = tg_print_conf_uint, |
451af504d cgroup: replace c... |
1167 |
.write = tg_set_conf_uint, |
60c2bc2d5 blkcg: move conf/... |
1168 1169 1170 |
}, { .name = "throttle.io_service_bytes", |
77ea73388 blkcg: move io_se... |
1171 1172 |
.private = (unsigned long)&blkcg_policy_throtl, .seq_show = blkg_print_stat_bytes, |
60c2bc2d5 blkcg: move conf/... |
1173 1174 1175 |
}, { .name = "throttle.io_serviced", |
77ea73388 blkcg: move io_se... |
1176 1177 |
.private = (unsigned long)&blkcg_policy_throtl, .seq_show = blkg_print_stat_ios, |
60c2bc2d5 blkcg: move conf/... |
1178 1179 1180 |
}, { } /* terminate */ }; |
2ee867dcf blkcg: implement ... |
1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 |
static u64 tg_prfill_max(struct seq_file *sf, struct blkg_policy_data *pd, int off) { struct throtl_grp *tg = pd_to_tg(pd); const char *dname = blkg_dev_name(pd->blkg); char bufs[4][21] = { "max", "max", "max", "max" }; if (!dname) return 0; if (tg->bps[READ] == -1 && tg->bps[WRITE] == -1 && tg->iops[READ] == -1 && tg->iops[WRITE] == -1) return 0; if (tg->bps[READ] != -1) snprintf(bufs[0], sizeof(bufs[0]), "%llu", tg->bps[READ]); if (tg->bps[WRITE] != -1) snprintf(bufs[1], sizeof(bufs[1]), "%llu", tg->bps[WRITE]); if (tg->iops[READ] != -1) snprintf(bufs[2], sizeof(bufs[2]), "%u", tg->iops[READ]); if (tg->iops[WRITE] != -1) snprintf(bufs[3], sizeof(bufs[3]), "%u", tg->iops[WRITE]); seq_printf(sf, "%s rbps=%s wbps=%s riops=%s wiops=%s ", dname, bufs[0], bufs[1], bufs[2], bufs[3]); return 0; } static int tg_print_max(struct seq_file *sf, void *v) { blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_max, &blkcg_policy_throtl, seq_cft(sf)->private, false); return 0; } static ssize_t tg_set_max(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { struct blkcg *blkcg = css_to_blkcg(of_css(of)); struct blkg_conf_ctx ctx; struct throtl_grp *tg; u64 v[4]; int ret; ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx); if (ret) return ret; tg = blkg_to_tg(ctx.blkg); v[0] = tg->bps[READ]; v[1] = tg->bps[WRITE]; v[2] = tg->iops[READ]; v[3] = tg->iops[WRITE]; while (true) { char tok[27]; /* wiops=18446744073709551616 */ char *p; u64 val = -1; int len; if (sscanf(ctx.body, "%26s%n", tok, &len) != 1) break; if (tok[0] == '\0') break; ctx.body += len; ret = -EINVAL; p = tok; strsep(&p, "="); if (!p || (sscanf(p, "%llu", &val) != 1 && strcmp(p, "max"))) goto out_finish; ret = -ERANGE; if (!val) goto out_finish; ret = -EINVAL; if (!strcmp(tok, "rbps")) v[0] = val; else if (!strcmp(tok, "wbps")) v[1] = val; else if (!strcmp(tok, "riops")) v[2] = min_t(u64, val, UINT_MAX); else if (!strcmp(tok, "wiops")) v[3] = min_t(u64, val, UINT_MAX); else goto out_finish; } tg->bps[READ] = v[0]; tg->bps[WRITE] = v[1]; tg->iops[READ] = v[2]; tg->iops[WRITE] = v[3]; tg_conf_updated(tg); ret = 0; out_finish: blkg_conf_finish(&ctx); return ret ?: nbytes; } static struct cftype throtl_files[] = { { .name = "max", .flags = CFTYPE_NOT_ON_ROOT, .seq_show = tg_print_max, .write = tg_set_max, }, { } /* terminate */ }; |
da5277700 block: Move blk_t... |
1292 |
static void throtl_shutdown_wq(struct request_queue *q) |
e43473b7f blkio: Core imple... |
1293 1294 |
{ struct throtl_data *td = q->td; |
69df0ab03 blk-throttle: sep... |
1295 |
cancel_work_sync(&td->dispatch_work); |
e43473b7f blkio: Core imple... |
1296 |
} |
3c798398e blkcg: mass renam... |
1297 |
static struct blkcg_policy blkcg_policy_throtl = { |
2ee867dcf blkcg: implement ... |
1298 |
.dfl_cftypes = throtl_files, |
880f50e22 blkcg: mark exist... |
1299 |
.legacy_cftypes = throtl_legacy_files, |
f9fcc2d39 blkcg: collapse b... |
1300 |
|
001bea73e blkcg: replace bl... |
1301 |
.pd_alloc_fn = throtl_pd_alloc, |
f9fcc2d39 blkcg: collapse b... |
1302 |
.pd_init_fn = throtl_pd_init, |
693e751e7 blk-throttle: imp... |
1303 |
.pd_online_fn = throtl_pd_online, |
001bea73e blkcg: replace bl... |
1304 |
.pd_free_fn = throtl_pd_free, |
e43473b7f blkio: Core imple... |
1305 |
}; |
ae1188963 blkcg: consolidat... |
1306 1307 |
bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, struct bio *bio) |
e43473b7f blkio: Core imple... |
1308 |
{ |
c5cc2070b blk-throttle: add... |
1309 |
struct throtl_qnode *qn = NULL; |
ae1188963 blkcg: consolidat... |
1310 |
struct throtl_grp *tg = blkg_to_tg(blkg ?: q->root_blkg); |
73f0d49a9 blk-throttle: mov... |
1311 |
struct throtl_service_queue *sq; |
0e9f4164b blk-throttle: gen... |
1312 |
bool rw = bio_data_dir(bio); |
bc16a4f93 block: reorganize... |
1313 |
bool throttled = false; |
e43473b7f blkio: Core imple... |
1314 |
|
ae1188963 blkcg: consolidat... |
1315 |
WARN_ON_ONCE(!rcu_read_lock_held()); |
2a0f61e6e blk-throttle: set... |
1316 |
/* see throtl_charge_bio() */ |
1eff9d322 block: rename bio... |
1317 |
if ((bio->bi_opf & REQ_THROTTLED) || !tg->has_rules[rw]) |
bc16a4f93 block: reorganize... |
1318 |
goto out; |
e43473b7f blkio: Core imple... |
1319 1320 |
spin_lock_irq(q->queue_lock); |
c9589f03e blk-throttle: imp... |
1321 1322 |
if (unlikely(blk_queue_bypass(q))) |
bc16a4f93 block: reorganize... |
1323 |
goto out_unlock; |
f469a7b4d blk-cgroup: Allow... |
1324 |
|
73f0d49a9 blk-throttle: mov... |
1325 |
sq = &tg->service_queue; |
9e660acff blk-throttle: mak... |
1326 1327 1328 1329 |
while (true) { /* throtl is FIFO - if bios are already queued, should queue */ if (sq->nr_queued[rw]) break; |
de701c74a blk-throttle: Som... |
1330 |
|
9e660acff blk-throttle: mak... |
1331 1332 1333 1334 1335 |
/* if above limits, break to queue */ if (!tg_may_dispatch(tg, bio, NULL)) break; /* within limits, let's charge and dispatch directly */ |
e43473b7f blkio: Core imple... |
1336 |
throtl_charge_bio(tg, bio); |
04521db04 blk-throttle: Res... |
1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 |
/* * We need to trim slice even when bios are not being queued * otherwise it might happen that a bio is not queued for * a long time and slice keeps on extending and trim is not * called for a long time. Now if limits are reduced suddenly * we take into account all the IO dispatched so far at new * low rate and * newly queued IO gets a really long dispatch * time. * * So keep on trimming slice even if bio is not queued. */ |
0f3457f60 blk-throttle: add... |
1349 |
throtl_trim_slice(tg, rw); |
9e660acff blk-throttle: mak... |
1350 1351 1352 1353 1354 1355 |
/* * @bio passed through this layer without being throttled. * Climb up the ladder. If we''re already at the top, it * can be executed directly. */ |
c5cc2070b blk-throttle: add... |
1356 |
qn = &tg->qnode_on_parent[rw]; |
9e660acff blk-throttle: mak... |
1357 1358 1359 1360 |
sq = sq->parent_sq; tg = sq_to_tg(sq); if (!tg) goto out_unlock; |
e43473b7f blkio: Core imple... |
1361 |
} |
9e660acff blk-throttle: mak... |
1362 |
/* out-of-limit, queue to @tg */ |
fda6f272c blk-throttle: imp... |
1363 1364 |
throtl_log(sq, "[%c] bio. bdisp=%llu sz=%u bps=%llu iodisp=%u iops=%u queued=%d/%d", rw == READ ? 'R' : 'W', |
4f024f379 block: Abstract o... |
1365 |
tg->bytes_disp[rw], bio->bi_iter.bi_size, tg->bps[rw], |
fda6f272c blk-throttle: imp... |
1366 1367 |
tg->io_disp[rw], tg->iops[rw], sq->nr_queued[READ], sq->nr_queued[WRITE]); |
e43473b7f blkio: Core imple... |
1368 |
|
671058fb2 block: make blk-t... |
1369 |
bio_associate_current(bio); |
6bc9c2b46 blk-throttle: mak... |
1370 |
tg->td->nr_queued[rw]++; |
c5cc2070b blk-throttle: add... |
1371 |
throtl_add_bio_tg(bio, qn, tg); |
bc16a4f93 block: reorganize... |
1372 |
throttled = true; |
e43473b7f blkio: Core imple... |
1373 |
|
7f52f98c2 blk-throttle: imp... |
1374 1375 1376 1377 1378 1379 |
/* * Update @tg's dispatch time and force schedule dispatch if @tg * was empty before @bio. The forced scheduling isn't likely to * cause undue delay as @bio is likely to be dispatched directly if * its @tg's disptime is not in the future. */ |
0e9f4164b blk-throttle: gen... |
1380 |
if (tg->flags & THROTL_TG_WAS_EMPTY) { |
77216b048 blk-throttle: add... |
1381 |
tg_update_disptime(tg); |
7f52f98c2 blk-throttle: imp... |
1382 |
throtl_schedule_next_dispatch(tg->service_queue.parent_sq, true); |
e43473b7f blkio: Core imple... |
1383 |
} |
bc16a4f93 block: reorganize... |
1384 |
out_unlock: |
e43473b7f blkio: Core imple... |
1385 |
spin_unlock_irq(q->queue_lock); |
bc16a4f93 block: reorganize... |
1386 |
out: |
2a0f61e6e blk-throttle: set... |
1387 1388 1389 1390 1391 1392 |
/* * As multiple blk-throtls may stack in the same issue path, we * don't want bios to leave with the flag set. Clear the flag if * being issued. */ if (!throttled) |
1eff9d322 block: rename bio... |
1393 |
bio->bi_opf &= ~REQ_THROTTLED; |
bc16a4f93 block: reorganize... |
1394 |
return throttled; |
e43473b7f blkio: Core imple... |
1395 |
} |
2a12f0dcd blk-throttle: mak... |
1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 |
/* * Dispatch all bios from all children tg's queued on @parent_sq. On * return, @parent_sq is guaranteed to not have any active children tg's * and all bios from previously active tg's are on @parent_sq->bio_lists[]. */ static void tg_drain_bios(struct throtl_service_queue *parent_sq) { struct throtl_grp *tg; while ((tg = throtl_rb_first(parent_sq))) { struct throtl_service_queue *sq = &tg->service_queue; struct bio *bio; throtl_dequeue_tg(tg); |
c5cc2070b blk-throttle: add... |
1410 |
while ((bio = throtl_peek_queued(&sq->queued[READ]))) |
2a12f0dcd blk-throttle: mak... |
1411 |
tg_dispatch_one_bio(tg, bio_data_dir(bio)); |
c5cc2070b blk-throttle: add... |
1412 |
while ((bio = throtl_peek_queued(&sq->queued[WRITE]))) |
2a12f0dcd blk-throttle: mak... |
1413 1414 1415 |
tg_dispatch_one_bio(tg, bio_data_dir(bio)); } } |
c9a929dde block: fix reques... |
1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 |
/** * blk_throtl_drain - drain throttled bios * @q: request_queue to drain throttled bios for * * Dispatch all currently throttled bios on @q through ->make_request_fn(). */ void blk_throtl_drain(struct request_queue *q) __releases(q->queue_lock) __acquires(q->queue_lock) { struct throtl_data *td = q->td; |
2a12f0dcd blk-throttle: mak... |
1426 |
struct blkcg_gq *blkg; |
492eb21b9 cgroup: make hier... |
1427 |
struct cgroup_subsys_state *pos_css; |
c9a929dde block: fix reques... |
1428 |
struct bio *bio; |
651930bc1 blk-throttle: dis... |
1429 |
int rw; |
c9a929dde block: fix reques... |
1430 |
|
8bcb6c7d4 block: use lockde... |
1431 |
queue_lockdep_assert_held(q); |
2a12f0dcd blk-throttle: mak... |
1432 |
rcu_read_lock(); |
c9a929dde block: fix reques... |
1433 |
|
2a12f0dcd blk-throttle: mak... |
1434 1435 1436 1437 1438 1439 |
/* * Drain each tg while doing post-order walk on the blkg tree, so * that all bios are propagated to td->service_queue. It'd be * better to walk service_queue tree directly but blkg walk is * easier. */ |
492eb21b9 cgroup: make hier... |
1440 |
blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) |
2a12f0dcd blk-throttle: mak... |
1441 |
tg_drain_bios(&blkg_to_tg(blkg)->service_queue); |
73f0d49a9 blk-throttle: mov... |
1442 |
|
2a12f0dcd blk-throttle: mak... |
1443 1444 1445 1446 |
/* finally, transfer bios from top-level tg's into the td */ tg_drain_bios(&td->service_queue); rcu_read_unlock(); |
c9a929dde block: fix reques... |
1447 |
spin_unlock_irq(q->queue_lock); |
2a12f0dcd blk-throttle: mak... |
1448 |
/* all bios now should be in td->service_queue, issue them */ |
651930bc1 blk-throttle: dis... |
1449 |
for (rw = READ; rw <= WRITE; rw++) |
c5cc2070b blk-throttle: add... |
1450 1451 |
while ((bio = throtl_pop_queued(&td->service_queue.queued[rw], NULL))) |
651930bc1 blk-throttle: dis... |
1452 |
generic_make_request(bio); |
c9a929dde block: fix reques... |
1453 1454 1455 |
spin_lock_irq(q->queue_lock); } |
e43473b7f blkio: Core imple... |
1456 1457 1458 |
int blk_throtl_init(struct request_queue *q) { struct throtl_data *td; |
a2b1693ba blkcg: implement ... |
1459 |
int ret; |
e43473b7f blkio: Core imple... |
1460 1461 1462 1463 |
td = kzalloc_node(sizeof(*td), GFP_KERNEL, q->node); if (!td) return -ENOMEM; |
69df0ab03 blk-throttle: sep... |
1464 |
INIT_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn); |
b2ce2643c blk-throttle: cle... |
1465 |
throtl_service_queue_init(&td->service_queue); |
e43473b7f blkio: Core imple... |
1466 |
|
cd1604fab blkcg: factor out... |
1467 |
q->td = td; |
29b125892 blk-throttle: Dyn... |
1468 |
td->queue = q; |
02977e4af blkio: Add root g... |
1469 |
|
a2b1693ba blkcg: implement ... |
1470 |
/* activate policy */ |
3c798398e blkcg: mass renam... |
1471 |
ret = blkcg_activate_policy(q, &blkcg_policy_throtl); |
a2b1693ba blkcg: implement ... |
1472 |
if (ret) |
f51b802c1 blkcg: use the us... |
1473 |
kfree(td); |
a2b1693ba blkcg: implement ... |
1474 |
return ret; |
e43473b7f blkio: Core imple... |
1475 1476 1477 1478 |
} void blk_throtl_exit(struct request_queue *q) { |
c875f4d02 blkcg: drop unnec... |
1479 |
BUG_ON(!q->td); |
da5277700 block: Move blk_t... |
1480 |
throtl_shutdown_wq(q); |
3c798398e blkcg: mass renam... |
1481 |
blkcg_deactivate_policy(q, &blkcg_policy_throtl); |
c9a929dde block: fix reques... |
1482 |
kfree(q->td); |
e43473b7f blkio: Core imple... |
1483 1484 1485 1486 |
} static int __init throtl_init(void) { |
450adcbe5 blk-throttle: Do ... |
1487 1488 1489 1490 |
kthrotld_workqueue = alloc_workqueue("kthrotld", WQ_MEM_RECLAIM, 0); if (!kthrotld_workqueue) panic("Failed to create kthrotld "); |
3c798398e blkcg: mass renam... |
1491 |
return blkcg_policy_register(&blkcg_policy_throtl); |
e43473b7f blkio: Core imple... |
1492 1493 1494 |
} module_init(throtl_init); |