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authorVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>2019-09-16 20:53:21 +0300
committerMax Reitz <mreitz@redhat.com>2019-10-10 10:56:17 +0200
commit6e9b225f737d53afae8160d73da72ee8f38eb1a6 (patch)
tree58db9049da40b0b8c74421607f4366175e300257 /block/aio_task.c
parentee1e66d9570a763a07662883093bb297ba22c5ee (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.c124
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;
+}