diff options
Diffstat (limited to 'block/throttle-groups.c')
| -rw-r--r-- | block/throttle-groups.c | 252 |
1 files changed, 139 insertions, 113 deletions
diff --git a/block/throttle-groups.c b/block/throttle-groups.c index 4920e09495..59545e287e 100644 --- a/block/throttle-groups.c +++ b/block/throttle-groups.c @@ -23,13 +23,14 @@ */ #include "qemu/osdep.h" +#include "sysemu/block-backend.h" #include "block/throttle-groups.h" #include "qemu/queue.h" #include "qemu/thread.h" #include "sysemu/qtest.h" /* The ThrottleGroup structure (with its ThrottleState) is shared - * among different BlockDriverState and it's independent from + * among different BlockBackends and it's independent from * AioContext, so in order to use it from different threads it needs * its own locking. * @@ -39,26 +40,26 @@ * The whole ThrottleGroup structure is private and invisible to * outside users, that only use it through its ThrottleState. * - * In addition to the ThrottleGroup structure, BlockDriverState has + * In addition to the ThrottleGroup structure, BlockBackendPublic has * fields that need to be accessed by other members of the group and - * therefore also need to be protected by this lock. Once a BDS is - * registered in a group those fields can be accessed by other threads - * any time. + * therefore also need to be protected by this lock. Once a + * BlockBackend is registered in a group those fields can be accessed + * by other threads any time. * * Again, all this is handled internally and is mostly transparent to * the outside. The 'throttle_timers' field however has an additional * constraint because it may be temporarily invalid (see for example * bdrv_set_aio_context()). Therefore in this file a thread will - * access some other BDS's timers only after verifying that that BDS - * has throttled requests in the queue. + * access some other BlockBackend's timers only after verifying that + * that BlockBackend has throttled requests in the queue. */ typedef struct ThrottleGroup { char *name; /* This is constant during the lifetime of the group */ QemuMutex lock; /* This lock protects the following four fields */ ThrottleState ts; - QLIST_HEAD(, BlockDriverState) head; - BlockDriverState *tokens[2]; + QLIST_HEAD(, BlockBackendPublic) head; + BlockBackend *tokens[2]; bool any_timer_armed[2]; /* These two are protected by the global throttle_groups_lock */ @@ -132,93 +133,98 @@ void throttle_group_unref(ThrottleState *ts) qemu_mutex_unlock(&throttle_groups_lock); } -/* Get the name from a BlockDriverState's ThrottleGroup. The name (and - * the pointer) is guaranteed to remain constant during the lifetime - * of the group. +/* Get the name from a BlockBackend's ThrottleGroup. The name (and the pointer) + * is guaranteed to remain constant during the lifetime of the group. * - * @bs: a BlockDriverState that is member of a throttling group + * @blk: a BlockBackend that is member of a throttling group * @ret: the name of the group. */ -const char *throttle_group_get_name(BlockDriverState *bs) +const char *throttle_group_get_name(BlockBackend *blk) { - ThrottleGroup *tg = container_of(bs->throttle_state, ThrottleGroup, ts); + BlockBackendPublic *blkp = blk_get_public(blk); + ThrottleGroup *tg = container_of(blkp->throttle_state, ThrottleGroup, ts); return tg->name; } -/* Return the next BlockDriverState in the round-robin sequence, - * simulating a circular list. +/* Return the next BlockBackend in the round-robin sequence, simulating a + * circular list. * * This assumes that tg->lock is held. * - * @bs: the current BlockDriverState - * @ret: the next BlockDriverState in the sequence + * @blk: the current BlockBackend + * @ret: the next BlockBackend in the sequence */ -static BlockDriverState *throttle_group_next_bs(BlockDriverState *bs) +static BlockBackend *throttle_group_next_blk(BlockBackend *blk) { - ThrottleState *ts = bs->throttle_state; + BlockBackendPublic *blkp = blk_get_public(blk); + ThrottleState *ts = blkp->throttle_state; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); - BlockDriverState *next = QLIST_NEXT(bs, round_robin); + BlockBackendPublic *next = QLIST_NEXT(blkp, round_robin); if (!next) { - return QLIST_FIRST(&tg->head); + next = QLIST_FIRST(&tg->head); } - return next; + return blk_by_public(next); } -/* Return the next BlockDriverState in the round-robin sequence with - * pending I/O requests. +/* Return the next BlockBackend in the round-robin sequence with pending I/O + * requests. * * This assumes that tg->lock is held. * - * @bs: the current BlockDriverState + * @blk: the current BlockBackend * @is_write: the type of operation (read/write) - * @ret: the next BlockDriverState with pending requests, or bs - * if there is none. + * @ret: the next BlockBackend with pending requests, or blk if there is + * none. */ -static BlockDriverState *next_throttle_token(BlockDriverState *bs, - bool is_write) +static BlockBackend *next_throttle_token(BlockBackend *blk, bool is_write) { - ThrottleGroup *tg = container_of(bs->throttle_state, ThrottleGroup, ts); - BlockDriverState *token, *start; + BlockBackendPublic *blkp = blk_get_public(blk); + ThrottleGroup *tg = container_of(blkp->throttle_state, ThrottleGroup, ts); + BlockBackend *token, *start; start = token = tg->tokens[is_write]; /* get next bs round in round robin style */ - token = throttle_group_next_bs(token); - while (token != start && !token->pending_reqs[is_write]) { - token = throttle_group_next_bs(token); + token = throttle_group_next_blk(token); + while (token != start && !blkp->pending_reqs[is_write]) { + token = throttle_group_next_blk(token); } /* If no IO are queued for scheduling on the next round robin token * then decide the token is the current bs because chances are * the current bs get the current request queued. */ - if (token == start && !token->pending_reqs[is_write]) { - token = bs; + if (token == start && !blkp->pending_reqs[is_write]) { + token = blk; } return token; } -/* Check if the next I/O request for a BlockDriverState needs to be - * throttled or not. If there's no timer set in this group, set one - * and update the token accordingly. +/* Check if the next I/O request for a BlockBackend needs to be throttled or + * not. If there's no timer set in this group, set one and update the token + * accordingly. * * This assumes that tg->lock is held. * - * @bs: the current BlockDriverState + * @blk: the current BlockBackend * @is_write: the type of operation (read/write) * @ret: whether the I/O request needs to be throttled or not */ -static bool throttle_group_schedule_timer(BlockDriverState *bs, - bool is_write) +static bool throttle_group_schedule_timer(BlockBackend *blk, bool is_write) { - ThrottleState *ts = bs->throttle_state; - ThrottleTimers *tt = &bs->throttle_timers; + BlockBackendPublic *blkp = blk_get_public(blk); + ThrottleState *ts = blkp->throttle_state; + ThrottleTimers *tt = &blkp->throttle_timers; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); bool must_wait; + if (blkp->io_limits_disabled) { + return false; + } + /* Check if any of the timers in this group is already armed */ if (tg->any_timer_armed[is_write]) { return true; @@ -226,9 +232,9 @@ static bool throttle_group_schedule_timer(BlockDriverState *bs, must_wait = throttle_schedule_timer(ts, tt, is_write); - /* If a timer just got armed, set bs as the current token */ + /* If a timer just got armed, set blk as the current token */ if (must_wait) { - tg->tokens[is_write] = bs; + tg->tokens[is_write] = blk; tg->any_timer_armed[is_write] = true; } @@ -239,18 +245,19 @@ static bool throttle_group_schedule_timer(BlockDriverState *bs, * * This assumes that tg->lock is held. * - * @bs: the current BlockDriverState + * @blk: the current BlockBackend * @is_write: the type of operation (read/write) */ -static void schedule_next_request(BlockDriverState *bs, bool is_write) +static void schedule_next_request(BlockBackend *blk, bool is_write) { - ThrottleGroup *tg = container_of(bs->throttle_state, ThrottleGroup, ts); + BlockBackendPublic *blkp = blk_get_public(blk); + ThrottleGroup *tg = container_of(blkp->throttle_state, ThrottleGroup, ts); bool must_wait; - BlockDriverState *token; + BlockBackend *token; /* Check if there's any pending request to schedule next */ - token = next_throttle_token(bs, is_write); - if (!token->pending_reqs[is_write]) { + token = next_throttle_token(blk, is_write); + if (!blkp->pending_reqs[is_write]) { return; } @@ -259,12 +266,12 @@ static void schedule_next_request(BlockDriverState *bs, bool is_write) /* If it doesn't have to wait, queue it for immediate execution */ if (!must_wait) { - /* Give preference to requests from the current bs */ + /* Give preference to requests from the current blk */ if (qemu_in_coroutine() && - qemu_co_queue_next(&bs->throttled_reqs[is_write])) { - token = bs; + qemu_co_queue_next(&blkp->throttled_reqs[is_write])) { + token = blk; } else { - ThrottleTimers *tt = &token->throttle_timers; + ThrottleTimers *tt = &blkp->throttle_timers; int64_t now = qemu_clock_get_ns(tt->clock_type); timer_mod(tt->timers[is_write], now + 1); tg->any_timer_armed[is_write] = true; @@ -277,53 +284,67 @@ static void schedule_next_request(BlockDriverState *bs, bool is_write) * if necessary, and schedule the next request using a round robin * algorithm. * - * @bs: the current BlockDriverState + * @blk: the current BlockBackend * @bytes: the number of bytes for this I/O * @is_write: the type of operation (read/write) */ -void coroutine_fn throttle_group_co_io_limits_intercept(BlockDriverState *bs, +void coroutine_fn throttle_group_co_io_limits_intercept(BlockBackend *blk, unsigned int bytes, bool is_write) { bool must_wait; - BlockDriverState *token; + BlockBackend *token; - ThrottleGroup *tg = container_of(bs->throttle_state, ThrottleGroup, ts); + BlockBackendPublic *blkp = blk_get_public(blk); + ThrottleGroup *tg = container_of(blkp->throttle_state, ThrottleGroup, ts); qemu_mutex_lock(&tg->lock); /* First we check if this I/O has to be throttled. */ - token = next_throttle_token(bs, is_write); + token = next_throttle_token(blk, is_write); must_wait = throttle_group_schedule_timer(token, is_write); /* Wait if there's a timer set or queued requests of this type */ - if (must_wait || bs->pending_reqs[is_write]) { - bs->pending_reqs[is_write]++; + if (must_wait || blkp->pending_reqs[is_write]) { + blkp->pending_reqs[is_write]++; qemu_mutex_unlock(&tg->lock); - qemu_co_queue_wait(&bs->throttled_reqs[is_write]); + qemu_co_queue_wait(&blkp->throttled_reqs[is_write]); qemu_mutex_lock(&tg->lock); - bs->pending_reqs[is_write]--; + blkp->pending_reqs[is_write]--; } /* The I/O will be executed, so do the accounting */ - throttle_account(bs->throttle_state, is_write, bytes); + throttle_account(blkp->throttle_state, is_write, bytes); /* Schedule the next request */ - schedule_next_request(bs, is_write); + schedule_next_request(blk, is_write); qemu_mutex_unlock(&tg->lock); } +void throttle_group_restart_blk(BlockBackend *blk) +{ + BlockBackendPublic *blkp = blk_get_public(blk); + int i; + + for (i = 0; i < 2; i++) { + while (qemu_co_enter_next(&blkp->throttled_reqs[i])) { + ; + } + } +} + /* Update the throttle configuration for a particular group. Similar * to throttle_config(), but guarantees atomicity within the * throttling group. * - * @bs: a BlockDriverState that is member of the group + * @blk: a BlockBackend that is a member of the group * @cfg: the configuration to set */ -void throttle_group_config(BlockDriverState *bs, ThrottleConfig *cfg) +void throttle_group_config(BlockBackend *blk, ThrottleConfig *cfg) { - ThrottleTimers *tt = &bs->throttle_timers; - ThrottleState *ts = bs->throttle_state; + BlockBackendPublic *blkp = blk_get_public(blk); + ThrottleTimers *tt = &blkp->throttle_timers; + ThrottleState *ts = blkp->throttle_state; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); qemu_mutex_lock(&tg->lock); /* throttle_config() cancels the timers */ @@ -335,18 +356,22 @@ void throttle_group_config(BlockDriverState *bs, ThrottleConfig *cfg) } throttle_config(ts, tt, cfg); qemu_mutex_unlock(&tg->lock); + + qemu_co_enter_next(&blkp->throttled_reqs[0]); + qemu_co_enter_next(&blkp->throttled_reqs[1]); } /* Get the throttle configuration from a particular group. Similar to * throttle_get_config(), but guarantees atomicity within the * throttling group. * - * @bs: a BlockDriverState that is member of the group + * @blk: a BlockBackend that is a member of the group * @cfg: the configuration will be written here */ -void throttle_group_get_config(BlockDriverState *bs, ThrottleConfig *cfg) +void throttle_group_get_config(BlockBackend *blk, ThrottleConfig *cfg) { - ThrottleState *ts = bs->throttle_state; + BlockBackendPublic *blkp = blk_get_public(blk); + ThrottleState *ts = blkp->throttle_state; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); qemu_mutex_lock(&tg->lock); throttle_get_config(ts, cfg); @@ -356,12 +381,13 @@ void throttle_group_get_config(BlockDriverState *bs, ThrottleConfig *cfg) /* ThrottleTimers callback. This wakes up a request that was waiting * because it had been throttled. * - * @bs: the BlockDriverState whose request had been throttled + * @blk: the BlockBackend whose request had been throttled * @is_write: the type of operation (read/write) */ -static void timer_cb(BlockDriverState *bs, bool is_write) +static void timer_cb(BlockBackend *blk, bool is_write) { - ThrottleState *ts = bs->throttle_state; + BlockBackendPublic *blkp = blk_get_public(blk); + ThrottleState *ts = blkp->throttle_state; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); bool empty_queue; @@ -371,13 +397,13 @@ static void timer_cb(BlockDriverState *bs, bool is_write) qemu_mutex_unlock(&tg->lock); /* Run the request that was waiting for this timer */ - empty_queue = !qemu_co_enter_next(&bs->throttled_reqs[is_write]); + empty_queue = !qemu_co_enter_next(&blkp->throttled_reqs[is_write]); /* If the request queue was empty then we have to take care of * scheduling the next one */ if (empty_queue) { qemu_mutex_lock(&tg->lock); - schedule_next_request(bs, is_write); + schedule_next_request(blk, is_write); qemu_mutex_unlock(&tg->lock); } } @@ -392,17 +418,17 @@ static void write_timer_cb(void *opaque) timer_cb(opaque, true); } -/* Register a BlockDriverState in the throttling group, also - * initializing its timers and updating its throttle_state pointer to - * point to it. If a throttling group with that name does not exist - * yet, it will be created. +/* Register a BlockBackend in the throttling group, also initializing its + * timers and updating its throttle_state pointer to point to it. If a + * throttling group with that name does not exist yet, it will be created. * - * @bs: the BlockDriverState to insert + * @blk: the BlockBackend to insert * @groupname: the name of the group */ -void throttle_group_register_bs(BlockDriverState *bs, const char *groupname) +void throttle_group_register_blk(BlockBackend *blk, const char *groupname) { int i; + BlockBackendPublic *blkp = blk_get_public(blk); ThrottleState *ts = throttle_group_incref(groupname); ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); int clock_type = QEMU_CLOCK_REALTIME; @@ -412,67 +438,67 @@ void throttle_group_register_bs(BlockDriverState *bs, const char *groupname) clock_type = QEMU_CLOCK_VIRTUAL; } - bs->throttle_state = ts; + blkp->throttle_state = ts; qemu_mutex_lock(&tg->lock); - /* If the ThrottleGroup is new set this BlockDriverState as the token */ + /* If the ThrottleGroup is new set this BlockBackend as the token */ for (i = 0; i < 2; i++) { if (!tg->tokens[i]) { - tg->tokens[i] = bs; + tg->tokens[i] = blk; } } - QLIST_INSERT_HEAD(&tg->head, bs, round_robin); + QLIST_INSERT_HEAD(&tg->head, blkp, round_robin); - throttle_timers_init(&bs->throttle_timers, - bdrv_get_aio_context(bs), + throttle_timers_init(&blkp->throttle_timers, + blk_get_aio_context(blk), clock_type, read_timer_cb, write_timer_cb, - bs); + blk); qemu_mutex_unlock(&tg->lock); } -/* Unregister a BlockDriverState from its group, removing it from the - * list, destroying the timers and setting the throttle_state pointer - * to NULL. +/* Unregister a BlockBackend from its group, removing it from the list, + * destroying the timers and setting the throttle_state pointer to NULL. * - * The BlockDriverState must not have pending throttled requests, so - * the caller has to drain them first. + * The BlockBackend must not have pending throttled requests, so the caller has + * to drain them first. * * The group will be destroyed if it's empty after this operation. * - * @bs: the BlockDriverState to remove + * @blk: the BlockBackend to remove */ -void throttle_group_unregister_bs(BlockDriverState *bs) +void throttle_group_unregister_blk(BlockBackend *blk) { - ThrottleGroup *tg = container_of(bs->throttle_state, ThrottleGroup, ts); + BlockBackendPublic *blkp = blk_get_public(blk); + ThrottleGroup *tg = container_of(blkp->throttle_state, ThrottleGroup, ts); int i; - assert(bs->pending_reqs[0] == 0 && bs->pending_reqs[1] == 0); - assert(qemu_co_queue_empty(&bs->throttled_reqs[0])); - assert(qemu_co_queue_empty(&bs->throttled_reqs[1])); + assert(blkp->pending_reqs[0] == 0 && blkp->pending_reqs[1] == 0); + assert(qemu_co_queue_empty(&blkp->throttled_reqs[0])); + assert(qemu_co_queue_empty(&blkp->throttled_reqs[1])); qemu_mutex_lock(&tg->lock); for (i = 0; i < 2; i++) { - if (tg->tokens[i] == bs) { - BlockDriverState *token = throttle_group_next_bs(bs); - /* Take care of the case where this is the last bs in the group */ - if (token == bs) { + if (tg->tokens[i] == blk) { + BlockBackend *token = throttle_group_next_blk(blk); + /* Take care of the case where this is the last blk in the group */ + if (token == blk) { token = NULL; } tg->tokens[i] = token; } } - /* remove the current bs from the list */ - QLIST_REMOVE(bs, round_robin); - throttle_timers_destroy(&bs->throttle_timers); + /* remove the current blk from the list */ + QLIST_REMOVE(blkp, round_robin); + throttle_timers_destroy(&blkp->throttle_timers); qemu_mutex_unlock(&tg->lock); throttle_group_unref(&tg->ts); - bs->throttle_state = NULL; + blkp->throttle_state = NULL; } static void throttle_groups_init(void) |