diff options
author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2019-09-16 20:53:21 +0300 |
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committer | Max Reitz <mreitz@redhat.com> | 2019-10-10 10:56:17 +0200 |
commit | 6e9b225f737d53afae8160d73da72ee8f38eb1a6 (patch) | |
tree | 58db9049da40b0b8c74421607f4366175e300257 /block/aio_task.c | |
parent | ee1e66d9570a763a07662883093bb297ba22c5ee (diff) |
block: introduce aio task pool
Common interface for aio task loops. To be used for improving
performance of synchronous io loops in qcow2, block-stream,
copy-on-read, and may be other places.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190916175324.18478-3-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block/aio_task.c')
-rw-r--r-- | block/aio_task.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/block/aio_task.c b/block/aio_task.c new file mode 100644 index 0000000000..88989fa248 --- /dev/null +++ b/block/aio_task.c @@ -0,0 +1,124 @@ +/* + * Aio tasks loops + * + * Copyright (c) 2019 Virtuozzo International GmbH. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "qemu/osdep.h" +#include "block/aio.h" +#include "block/aio_task.h" + +struct AioTaskPool { + Coroutine *main_co; + int status; + int max_busy_tasks; + int busy_tasks; + bool waiting; +}; + +static void coroutine_fn aio_task_co(void *opaque) +{ + AioTask *task = opaque; + AioTaskPool *pool = task->pool; + + assert(pool->busy_tasks < pool->max_busy_tasks); + pool->busy_tasks++; + + task->ret = task->func(task); + + pool->busy_tasks--; + + if (task->ret < 0 && pool->status == 0) { + pool->status = task->ret; + } + + g_free(task); + + if (pool->waiting) { + pool->waiting = false; + aio_co_wake(pool->main_co); + } +} + +void coroutine_fn aio_task_pool_wait_one(AioTaskPool *pool) +{ + assert(pool->busy_tasks > 0); + assert(qemu_coroutine_self() == pool->main_co); + + pool->waiting = true; + qemu_coroutine_yield(); + + assert(!pool->waiting); + assert(pool->busy_tasks < pool->max_busy_tasks); +} + +void coroutine_fn aio_task_pool_wait_slot(AioTaskPool *pool) +{ + if (pool->busy_tasks < pool->max_busy_tasks) { + return; + } + + aio_task_pool_wait_one(pool); +} + +void coroutine_fn aio_task_pool_wait_all(AioTaskPool *pool) +{ + while (pool->busy_tasks > 0) { + aio_task_pool_wait_one(pool); + } +} + +void coroutine_fn aio_task_pool_start_task(AioTaskPool *pool, AioTask *task) +{ + aio_task_pool_wait_slot(pool); + + task->pool = pool; + qemu_coroutine_enter(qemu_coroutine_create(aio_task_co, task)); +} + +AioTaskPool *coroutine_fn aio_task_pool_new(int max_busy_tasks) +{ + AioTaskPool *pool = g_new0(AioTaskPool, 1); + + pool->main_co = qemu_coroutine_self(); + pool->max_busy_tasks = max_busy_tasks; + + return pool; +} + +void aio_task_pool_free(AioTaskPool *pool) +{ + g_free(pool); +} + +int aio_task_pool_status(AioTaskPool *pool) +{ + if (!pool) { + return 0; /* Sugar for lazy allocation of aio pool */ + } + + return pool->status; +} + +bool aio_task_pool_empty(AioTaskPool *pool) +{ + return pool->busy_tasks == 0; +} |