From 3b2337eff03e23ffcc7d6b0a0f72bd3ab2135ae9 Mon Sep 17 00:00:00 2001 From: zhenwei pi Date: Fri, 28 Jul 2023 10:20:06 +0800 Subject: [PATCH] block/throttle-groups: Use ThrottleDirection instread of bool is_write 'bool is_write' style is obsolete from throttle framework, adapt block throttle groups to the new style: - use ThrottleDirection instead of 'bool is_write'. Ex, schedule_next_request(ThrottleGroupMember *tgm, bool is_write) -> schedule_next_request(ThrottleGroupMember *tgm, ThrottleDirection direction) - use THROTTLE_MAX instead of hard code. Ex, ThrottleGroupMember *tokens[2] -> ThrottleGroupMember *tokens[THROTTLE_MAX] - use ThrottleDirection instead of hard code on iteration. Ex, (i = 0; i < 2; i++) -> for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) Use a simple python script to test the new style: #!/usr/bin/python3 import subprocess import random import time commands = ['virsh blkdeviotune jammy vda --write-bytes-sec ', \ 'virsh blkdeviotune jammy vda --write-iops-sec ', \ 'virsh blkdeviotune jammy vda --read-bytes-sec ', \ 'virsh blkdeviotune jammy vda --read-iops-sec '] for loop in range(1, 1000): time.sleep(random.randrange(3, 5)) command = commands[random.randrange(0, 3)] + str(random.randrange(0, 1000000)) subprocess.run(command, shell=True, check=True) This works fine. Signed-off-by: zhenwei pi Message-Id: <20230728022006.1098509-10-pizhenwei@bytedance.com> Reviewed-by: Hanna Czenczek Signed-off-by: Hanna Czenczek --- block/block-backend.c | 4 +- block/throttle-groups.c | 161 ++++++++++++++++---------------- block/throttle.c | 8 +- include/block/throttle-groups.h | 6 +- 4 files changed, 90 insertions(+), 89 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index 4009ed5fed..47d360c97a 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1341,7 +1341,7 @@ blk_co_do_preadv_part(BlockBackend *blk, int64_t offset, int64_t bytes, /* throttling disk I/O */ if (blk->public.throttle_group_member.throttle_state) { throttle_group_co_io_limits_intercept(&blk->public.throttle_group_member, - bytes, false); + bytes, THROTTLE_READ); } ret = bdrv_co_preadv_part(blk->root, offset, bytes, qiov, qiov_offset, @@ -1415,7 +1415,7 @@ blk_co_do_pwritev_part(BlockBackend *blk, int64_t offset, int64_t bytes, /* throttling disk I/O */ if (blk->public.throttle_group_member.throttle_state) { throttle_group_co_io_limits_intercept(&blk->public.throttle_group_member, - bytes, true); + bytes, THROTTLE_WRITE); } if (!blk->enable_write_cache) { diff --git a/block/throttle-groups.c b/block/throttle-groups.c index 3847d27801..3eda4c4e3d 100644 --- a/block/throttle-groups.c +++ b/block/throttle-groups.c @@ -37,7 +37,7 @@ static void throttle_group_obj_init(Object *obj); static void throttle_group_obj_complete(UserCreatable *obj, Error **errp); -static void timer_cb(ThrottleGroupMember *tgm, bool is_write); +static void timer_cb(ThrottleGroupMember *tgm, ThrottleDirection direction); /* The ThrottleGroup structure (with its ThrottleState) is shared * among different ThrottleGroupMembers and it's independent from @@ -73,8 +73,8 @@ struct ThrottleGroup { QemuMutex lock; /* This lock protects the following four fields */ ThrottleState ts; QLIST_HEAD(, ThrottleGroupMember) head; - ThrottleGroupMember *tokens[2]; - bool any_timer_armed[2]; + ThrottleGroupMember *tokens[THROTTLE_MAX]; + bool any_timer_armed[THROTTLE_MAX]; QEMUClockType clock_type; /* This field is protected by the global QEMU mutex */ @@ -197,13 +197,13 @@ static ThrottleGroupMember *throttle_group_next_tgm(ThrottleGroupMember *tgm) * This assumes that tg->lock is held. * * @tgm: the ThrottleGroupMember - * @is_write: the type of operation (read/write) + * @direction: the ThrottleDirection * @ret: whether the ThrottleGroupMember has pending requests. */ static inline bool tgm_has_pending_reqs(ThrottleGroupMember *tgm, - bool is_write) + ThrottleDirection direction) { - return tgm->pending_reqs[is_write]; + return tgm->pending_reqs[direction]; } /* Return the next ThrottleGroupMember in the round-robin sequence with pending @@ -212,12 +212,12 @@ static inline bool tgm_has_pending_reqs(ThrottleGroupMember *tgm, * This assumes that tg->lock is held. * * @tgm: the current ThrottleGroupMember - * @is_write: the type of operation (read/write) + * @direction: the ThrottleDirection * @ret: the next ThrottleGroupMember with pending requests, or tgm if * there is none. */ static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm, - bool is_write) + ThrottleDirection direction) { ThrottleState *ts = tgm->throttle_state; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); @@ -227,16 +227,16 @@ static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm, * it's being drained. Skip the round-robin search and return tgm * immediately if it has pending requests. Otherwise we could be * forcing it to wait for other member's throttled requests. */ - if (tgm_has_pending_reqs(tgm, is_write) && + if (tgm_has_pending_reqs(tgm, direction) && qatomic_read(&tgm->io_limits_disabled)) { return tgm; } - start = token = tg->tokens[is_write]; + start = token = tg->tokens[direction]; /* get next bs round in round robin style */ token = throttle_group_next_tgm(token); - while (token != start && !tgm_has_pending_reqs(token, is_write)) { + while (token != start && !tgm_has_pending_reqs(token, direction)) { token = throttle_group_next_tgm(token); } @@ -244,12 +244,12 @@ static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm, * then decide the token is the current tgm because chances are * the current tgm got the current request queued. */ - if (token == start && !tgm_has_pending_reqs(token, is_write)) { + if (token == start && !tgm_has_pending_reqs(token, direction)) { token = tgm; } /* Either we return the original TGM, or one with pending requests */ - assert(token == tgm || tgm_has_pending_reqs(token, is_write)); + assert(token == tgm || tgm_has_pending_reqs(token, direction)); return token; } @@ -261,16 +261,15 @@ static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm, * This assumes that tg->lock is held. * * @tgm: the current ThrottleGroupMember - * @is_write: the type of operation (read/write) + * @direction: the ThrottleDirection * @ret: whether the I/O request needs to be throttled or not */ static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm, - bool is_write) + ThrottleDirection direction) { ThrottleState *ts = tgm->throttle_state; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); ThrottleTimers *tt = &tgm->throttle_timers; - ThrottleDirection direction = is_write ? THROTTLE_WRITE : THROTTLE_READ; bool must_wait; if (qatomic_read(&tgm->io_limits_disabled)) { @@ -278,7 +277,7 @@ static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm, } /* Check if any of the timers in this group is already armed */ - if (tg->any_timer_armed[is_write]) { + if (tg->any_timer_armed[direction]) { return true; } @@ -286,8 +285,8 @@ static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm, /* If a timer just got armed, set tgm as the current token */ if (must_wait) { - tg->tokens[is_write] = tgm; - tg->any_timer_armed[is_write] = true; + tg->tokens[direction] = tgm; + tg->any_timer_armed[direction] = true; } return must_wait; @@ -297,15 +296,15 @@ static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm, * any request was actually pending. * * @tgm: the current ThrottleGroupMember - * @is_write: the type of operation (read/write) + * @direction: the ThrottleDirection */ static bool coroutine_fn throttle_group_co_restart_queue(ThrottleGroupMember *tgm, - bool is_write) + ThrottleDirection direction) { bool ret; qemu_co_mutex_lock(&tgm->throttled_reqs_lock); - ret = qemu_co_queue_next(&tgm->throttled_reqs[is_write]); + ret = qemu_co_queue_next(&tgm->throttled_reqs[direction]); qemu_co_mutex_unlock(&tgm->throttled_reqs_lock); return ret; @@ -316,9 +315,10 @@ static bool coroutine_fn throttle_group_co_restart_queue(ThrottleGroupMember *tg * This assumes that tg->lock is held. * * @tgm: the current ThrottleGroupMember - * @is_write: the type of operation (read/write) + * @direction: the ThrottleDirection */ -static void schedule_next_request(ThrottleGroupMember *tgm, bool is_write) +static void schedule_next_request(ThrottleGroupMember *tgm, + ThrottleDirection direction) { ThrottleState *ts = tgm->throttle_state; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); @@ -326,27 +326,27 @@ static void schedule_next_request(ThrottleGroupMember *tgm, bool is_write) ThrottleGroupMember *token; /* Check if there's any pending request to schedule next */ - token = next_throttle_token(tgm, is_write); - if (!tgm_has_pending_reqs(token, is_write)) { + token = next_throttle_token(tgm, direction); + if (!tgm_has_pending_reqs(token, direction)) { return; } /* Set a timer for the request if it needs to be throttled */ - must_wait = throttle_group_schedule_timer(token, is_write); + must_wait = throttle_group_schedule_timer(token, direction); /* If it doesn't have to wait, queue it for immediate execution */ if (!must_wait) { /* Give preference to requests from the current tgm */ if (qemu_in_coroutine() && - throttle_group_co_restart_queue(tgm, is_write)) { + throttle_group_co_restart_queue(tgm, direction)) { token = tgm; } else { ThrottleTimers *tt = &token->throttle_timers; int64_t now = qemu_clock_get_ns(tg->clock_type); - timer_mod(tt->timers[is_write], now); - tg->any_timer_armed[is_write] = true; + timer_mod(tt->timers[direction], now); + tg->any_timer_armed[direction] = true; } - tg->tokens[is_write] = token; + tg->tokens[direction] = token; } } @@ -356,49 +356,49 @@ static void schedule_next_request(ThrottleGroupMember *tgm, bool is_write) * * @tgm: the current ThrottleGroupMember * @bytes: the number of bytes for this I/O - * @is_write: the type of operation (read/write) + * @direction: the ThrottleDirection */ void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm, int64_t bytes, - bool is_write) + ThrottleDirection direction) { bool must_wait; ThrottleGroupMember *token; ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts); - ThrottleDirection direction = is_write ? THROTTLE_WRITE : THROTTLE_READ; assert(bytes >= 0); + assert(direction < THROTTLE_MAX); qemu_mutex_lock(&tg->lock); /* First we check if this I/O has to be throttled. */ - token = next_throttle_token(tgm, is_write); - must_wait = throttle_group_schedule_timer(token, is_write); + token = next_throttle_token(tgm, direction); + must_wait = throttle_group_schedule_timer(token, direction); /* Wait if there's a timer set or queued requests of this type */ - if (must_wait || tgm->pending_reqs[is_write]) { - tgm->pending_reqs[is_write]++; + if (must_wait || tgm->pending_reqs[direction]) { + tgm->pending_reqs[direction]++; qemu_mutex_unlock(&tg->lock); qemu_co_mutex_lock(&tgm->throttled_reqs_lock); - qemu_co_queue_wait(&tgm->throttled_reqs[is_write], + qemu_co_queue_wait(&tgm->throttled_reqs[direction], &tgm->throttled_reqs_lock); qemu_co_mutex_unlock(&tgm->throttled_reqs_lock); qemu_mutex_lock(&tg->lock); - tgm->pending_reqs[is_write]--; + tgm->pending_reqs[direction]--; } /* The I/O will be executed, so do the accounting */ throttle_account(tgm->throttle_state, direction, bytes); /* Schedule the next request */ - schedule_next_request(tgm, is_write); + schedule_next_request(tgm, direction); qemu_mutex_unlock(&tg->lock); } typedef struct { ThrottleGroupMember *tgm; - bool is_write; + ThrottleDirection direction; } RestartData; static void coroutine_fn throttle_group_restart_queue_entry(void *opaque) @@ -407,16 +407,16 @@ static void coroutine_fn throttle_group_restart_queue_entry(void *opaque) ThrottleGroupMember *tgm = data->tgm; ThrottleState *ts = tgm->throttle_state; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); - bool is_write = data->is_write; + ThrottleDirection direction = data->direction; bool empty_queue; - empty_queue = !throttle_group_co_restart_queue(tgm, is_write); + empty_queue = !throttle_group_co_restart_queue(tgm, direction); /* 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(tgm, is_write); + schedule_next_request(tgm, direction); qemu_mutex_unlock(&tg->lock); } @@ -426,18 +426,19 @@ static void coroutine_fn throttle_group_restart_queue_entry(void *opaque) aio_wait_kick(); } -static void throttle_group_restart_queue(ThrottleGroupMember *tgm, bool is_write) +static void throttle_group_restart_queue(ThrottleGroupMember *tgm, + ThrottleDirection direction) { Coroutine *co; RestartData *rd = g_new0(RestartData, 1); rd->tgm = tgm; - rd->is_write = is_write; + rd->direction = direction; /* This function is called when a timer is fired or when * throttle_group_restart_tgm() is called. Either way, there can * be no timer pending on this tgm at this point */ - assert(!timer_pending(tgm->throttle_timers.timers[is_write])); + assert(!timer_pending(tgm->throttle_timers.timers[direction])); qatomic_inc(&tgm->restart_pending); @@ -447,18 +448,18 @@ static void throttle_group_restart_queue(ThrottleGroupMember *tgm, bool is_write void throttle_group_restart_tgm(ThrottleGroupMember *tgm) { - int i; + ThrottleDirection dir; if (tgm->throttle_state) { - for (i = 0; i < 2; i++) { - QEMUTimer *t = tgm->throttle_timers.timers[i]; + for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) { + QEMUTimer *t = tgm->throttle_timers.timers[dir]; if (timer_pending(t)) { /* If there's a pending timer on this tgm, fire it now */ timer_del(t); - timer_cb(tgm, i); + timer_cb(tgm, dir); } else { /* Else run the next request from the queue manually */ - throttle_group_restart_queue(tgm, i); + throttle_group_restart_queue(tgm, dir); } } } @@ -502,30 +503,30 @@ void throttle_group_get_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg) * because it had been throttled. * * @tgm: the ThrottleGroupMember whose request had been throttled - * @is_write: the type of operation (read/write) + * @direction: the ThrottleDirection */ -static void timer_cb(ThrottleGroupMember *tgm, bool is_write) +static void timer_cb(ThrottleGroupMember *tgm, ThrottleDirection direction) { ThrottleState *ts = tgm->throttle_state; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); /* The timer has just been fired, so we can update the flag */ qemu_mutex_lock(&tg->lock); - tg->any_timer_armed[is_write] = false; + tg->any_timer_armed[direction] = false; qemu_mutex_unlock(&tg->lock); /* Run the request that was waiting for this timer */ - throttle_group_restart_queue(tgm, is_write); + throttle_group_restart_queue(tgm, direction); } static void read_timer_cb(void *opaque) { - timer_cb(opaque, false); + timer_cb(opaque, THROTTLE_READ); } static void write_timer_cb(void *opaque) { - timer_cb(opaque, true); + timer_cb(opaque, THROTTLE_WRITE); } /* Register a ThrottleGroupMember from the throttling group, also initializing @@ -543,7 +544,7 @@ void throttle_group_register_tgm(ThrottleGroupMember *tgm, const char *groupname, AioContext *ctx) { - int i; + ThrottleDirection dir; ThrottleState *ts = throttle_group_incref(groupname); ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); @@ -553,10 +554,11 @@ void throttle_group_register_tgm(ThrottleGroupMember *tgm, QEMU_LOCK_GUARD(&tg->lock); /* If the ThrottleGroup is new set this ThrottleGroupMember as the token */ - for (i = 0; i < 2; i++) { - if (!tg->tokens[i]) { - tg->tokens[i] = tgm; + for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) { + if (!tg->tokens[dir]) { + tg->tokens[dir] = tgm; } + qemu_co_queue_init(&tgm->throttled_reqs[dir]); } QLIST_INSERT_HEAD(&tg->head, tgm, round_robin); @@ -568,8 +570,6 @@ void throttle_group_register_tgm(ThrottleGroupMember *tgm, write_timer_cb, tgm); qemu_co_mutex_init(&tgm->throttled_reqs_lock); - qemu_co_queue_init(&tgm->throttled_reqs[0]); - qemu_co_queue_init(&tgm->throttled_reqs[1]); } /* Unregister a ThrottleGroupMember from its group, removing it from the list, @@ -587,7 +587,7 @@ void throttle_group_unregister_tgm(ThrottleGroupMember *tgm) ThrottleState *ts = tgm->throttle_state; ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts); ThrottleGroupMember *token; - int i; + ThrottleDirection dir; if (!ts) { /* Discard already unregistered tgm */ @@ -598,17 +598,17 @@ void throttle_group_unregister_tgm(ThrottleGroupMember *tgm) AIO_WAIT_WHILE(tgm->aio_context, qatomic_read(&tgm->restart_pending) > 0); WITH_QEMU_LOCK_GUARD(&tg->lock) { - for (i = 0; i < 2; i++) { - assert(tgm->pending_reqs[i] == 0); - assert(qemu_co_queue_empty(&tgm->throttled_reqs[i])); - assert(!timer_pending(tgm->throttle_timers.timers[i])); - if (tg->tokens[i] == tgm) { + for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) { + assert(tgm->pending_reqs[dir] == 0); + assert(qemu_co_queue_empty(&tgm->throttled_reqs[dir])); + assert(!timer_pending(tgm->throttle_timers.timers[dir])); + if (tg->tokens[dir] == tgm) { token = throttle_group_next_tgm(tgm); /* Take care of the case where this is the last tgm in the group */ if (token == tgm) { token = NULL; } - tg->tokens[i] = token; + tg->tokens[dir] = token; } } @@ -633,19 +633,20 @@ void throttle_group_detach_aio_context(ThrottleGroupMember *tgm) { ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts); ThrottleTimers *tt = &tgm->throttle_timers; - int i; + ThrottleDirection dir; /* Requests must have been drained */ - assert(tgm->pending_reqs[0] == 0 && tgm->pending_reqs[1] == 0); - assert(qemu_co_queue_empty(&tgm->throttled_reqs[0])); - assert(qemu_co_queue_empty(&tgm->throttled_reqs[1])); + for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) { + assert(tgm->pending_reqs[dir] == 0); + assert(qemu_co_queue_empty(&tgm->throttled_reqs[dir])); + } /* Kick off next ThrottleGroupMember, if necessary */ WITH_QEMU_LOCK_GUARD(&tg->lock) { - for (i = 0; i < 2; i++) { - if (timer_pending(tt->timers[i])) { - tg->any_timer_armed[i] = false; - schedule_next_request(tgm, i); + for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) { + if (timer_pending(tt->timers[dir])) { + tg->any_timer_armed[dir] = false; + schedule_next_request(tgm, dir); } } } diff --git a/block/throttle.c b/block/throttle.c index 3aaef18d4e..1098a4ae9a 100644 --- a/block/throttle.c +++ b/block/throttle.c @@ -118,7 +118,7 @@ throttle_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, { ThrottleGroupMember *tgm = bs->opaque; - throttle_group_co_io_limits_intercept(tgm, bytes, false); + throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_READ); return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags); } @@ -128,7 +128,7 @@ throttle_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, QEMUIOVector *qiov, BdrvRequestFlags flags) { ThrottleGroupMember *tgm = bs->opaque; - throttle_group_co_io_limits_intercept(tgm, bytes, true); + throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_WRITE); return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags); } @@ -138,7 +138,7 @@ throttle_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, BdrvRequestFlags flags) { ThrottleGroupMember *tgm = bs->opaque; - throttle_group_co_io_limits_intercept(tgm, bytes, true); + throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_WRITE); return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags); } @@ -147,7 +147,7 @@ static int coroutine_fn GRAPH_RDLOCK throttle_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) { ThrottleGroupMember *tgm = bs->opaque; - throttle_group_co_io_limits_intercept(tgm, bytes, true); + throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_WRITE); return bdrv_co_pdiscard(bs->file, offset, bytes); } diff --git a/include/block/throttle-groups.h b/include/block/throttle-groups.h index ff282fc0f8..2355e8d9de 100644 --- a/include/block/throttle-groups.h +++ b/include/block/throttle-groups.h @@ -37,7 +37,7 @@ typedef struct ThrottleGroupMember { AioContext *aio_context; /* throttled_reqs_lock protects the CoQueues for throttled requests. */ CoMutex throttled_reqs_lock; - CoQueue throttled_reqs[2]; + CoQueue throttled_reqs[THROTTLE_MAX]; /* Nonzero if the I/O limits are currently being ignored; generally * it is zero. Accessed with atomic operations. @@ -54,7 +54,7 @@ typedef struct ThrottleGroupMember { * throttle_state tells us if I/O limits are configured. */ ThrottleState *throttle_state; ThrottleTimers throttle_timers; - unsigned pending_reqs[2]; + unsigned pending_reqs[THROTTLE_MAX]; QLIST_ENTRY(ThrottleGroupMember) round_robin; } ThrottleGroupMember; @@ -78,7 +78,7 @@ void throttle_group_restart_tgm(ThrottleGroupMember *tgm); void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm, int64_t bytes, - bool is_write); + ThrottleDirection direction); void throttle_group_attach_aio_context(ThrottleGroupMember *tgm, AioContext *new_context); void throttle_group_detach_aio_context(ThrottleGroupMember *tgm);