[Qemu-devel] [6870] Refactor aio callback allocation to use an aiocb pool (Avi Kivity)

[Anthony Liguori]

Revision: 6870
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6870
Author:   aliguori
Date:     2009-03-20 18:25:59 +0000 (Fri, 20 Mar 2009)
Log Message:
-----------
Refactor aio callback allocation to use an aiocb pool (Avi Kivity)

Move the AIOCB allocation code to use a dedicate structure, AIOPool.  AIOCB
specific information, such as the AIOCB size and cancellation routine, is
moved into the pool.

At present, there is exactly one pool per block format driver, maintaining
the status quo.

Signed-off-by: Avi Kivity <address@hidden>
Signed-off-by: Anthony Liguori <address@hidden>

Modified Paths:
--------------
    trunk/block.c
    trunk/block_int.h

Modified: trunk/block.c
===================================================================
--- trunk/block.c       2009-03-20 16:22:31 UTC (rev 6869)
+++ trunk/block.c       2009-03-20 18:25:59 UTC (rev 6870)
@@ -147,6 +147,7 @@
         bdrv->bdrv_read = bdrv_read_em;
         bdrv->bdrv_write = bdrv_write_em;
     }
+    aio_pool_init(&bdrv->aio_pool, bdrv->aiocb_size, bdrv->bdrv_aio_cancel);
     bdrv->next = first_drv;
     first_drv = bdrv;
 }
@@ -1371,14 +1372,12 @@
 
 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
 {
-    BlockDriver *drv = acb->bs->drv;
-
     if (acb->cb == bdrv_aio_rw_vector_cb) {
         VectorTranslationState *s = acb->opaque;
         acb = s->aiocb;
     }
 
-    drv->bdrv_aio_cancel(acb);
+    acb->pool->cancel(acb);
 }
 
 
@@ -1496,18 +1495,25 @@
     bdrv_register(&bdrv_nbd);
 }
 
-void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
-                   void *opaque)
+void aio_pool_init(AIOPool *pool, int aiocb_size,
+                   void (*cancel)(BlockDriverAIOCB *acb))
 {
-    BlockDriver *drv;
+    pool->aiocb_size = aiocb_size;
+    pool->cancel = cancel;
+    pool->free_aiocb = NULL;
+}
+
+void *qemu_aio_get_pool(AIOPool *pool, BlockDriverState *bs,
+                        BlockDriverCompletionFunc *cb, void *opaque)
+{
     BlockDriverAIOCB *acb;
 
-    drv = bs->drv;
-    if (drv->free_aiocb) {
-        acb = drv->free_aiocb;
-        drv->free_aiocb = acb->next;
+    if (pool->free_aiocb) {
+        acb = pool->free_aiocb;
+        pool->free_aiocb = acb->next;
     } else {
-        acb = qemu_mallocz(drv->aiocb_size);
+        acb = qemu_mallocz(pool->aiocb_size);
+        acb->pool = pool;
     }
     acb->bs = bs;
     acb->cb = cb;
@@ -1515,12 +1521,18 @@
     return acb;
 }
 
+void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
+                   void *opaque)
+{
+    return qemu_aio_get_pool(&bs->drv->aio_pool, bs, cb, opaque);
+}
+
 void qemu_aio_release(void *p)
 {
-    BlockDriverAIOCB *acb = p;
-    BlockDriver *drv = acb->bs->drv;
-    acb->next = drv->free_aiocb;
-    drv->free_aiocb = acb;
+    BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
+    AIOPool *pool = acb->pool;
+    acb->next = pool->free_aiocb;
+    pool->free_aiocb = acb;
 }
 
 /**************************************************************/

Modified: trunk/block_int.h
===================================================================
--- trunk/block_int.h   2009-03-20 16:22:31 UTC (rev 6869)
+++ trunk/block_int.h   2009-03-20 18:25:59 UTC (rev 6870)
@@ -30,6 +30,12 @@
 #define BLOCK_FLAG_COMPRESS    2
 #define BLOCK_FLAG_COMPAT6     4
 
+typedef struct AIOPool {
+    void (*cancel)(BlockDriverAIOCB *acb);
+    int aiocb_size;
+    BlockDriverAIOCB *free_aiocb;
+} AIOPool;
+
 struct BlockDriver {
     const char *format_name;
     int instance_size;
@@ -91,7 +97,7 @@
                                            BlockDriverCompletionFunc *cb,
                                            void *opaque);
 
-    BlockDriverAIOCB *free_aiocb;
+    AIOPool aio_pool;
     struct BlockDriver *next;
 };
 
@@ -141,6 +147,7 @@
 };
 
 struct BlockDriverAIOCB {
+    AIOPool *pool;
     BlockDriverState *bs;
     BlockDriverCompletionFunc *cb;
     void *opaque;
@@ -149,8 +156,13 @@
 
 void get_tmp_filename(char *filename, int size);
 
+void aio_pool_init(AIOPool *pool, int aiocb_size,
+                   void (*cancel)(BlockDriverAIOCB *acb));
+
 void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
                    void *opaque);
+void *qemu_aio_get_pool(AIOPool *pool, BlockDriverState *bs,
+                        BlockDriverCompletionFunc *cb, void *opaque);
 void qemu_aio_release(void *p);
 
 extern BlockDriverState *bdrv_first;