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authorChristoph Hellwig <hch@lst.de>2009-08-20 16:58:35 +0200
committerAnthony Liguori <aliguori@us.ibm.com>2009-08-27 20:30:22 -0500
commit5c6c3a6c54b23caa84fb4e046e85a461612279bb (patch)
tree7c23c2c86ca96f0a1b3dcbb86c70d5989e156710 /block.h
parent9ef91a677110ec200d7b2904fc4bcae5a77329ad (diff)
raw-posix: add Linux native AIO support
Now that do have a nicer interface to work against we can add Linux native AIO support. It's an extremly thing layer just setting up an iocb for the io_submit system call in the submission path, and registering an eventfd with the qemu poll handler to do complete the iocbs directly from there. This started out based on Anthony's earlier AIO patch, but after estimated 42,000 rewrites and just as many build system changes there's not much left of it. To enable native kernel aio use the aio=native sub-command on the drive command line. I have also added an option to qemu-io to test the aio support without needing a guest. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'block.h')
-rw-r--r--block.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/block.h b/block.h
index ccd4c1e700..28bf357091 100644
--- a/block.h
+++ b/block.h
@@ -37,6 +37,7 @@ typedef struct QEMUSnapshotInfo {
bdrv_file_open()) */
#define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */
#define BDRV_O_CACHE_WB 0x0040 /* use write-back caching */
+#define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */
#define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_CACHE_WB)