diff options
| author | Max Reitz <mreitz@redhat.com> | 2014-10-24 15:57:32 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-11-03 11:41:48 +0000 |
| commit | 94054183daffaa41cd77ced9301c01a01027923a (patch) | |
| tree | 75c6d4efe55d181cee75d7e3eaaf59ecbf1e9aa5 /include | |
| parent | 491d27e2af4f6e157c4b29d43269c5cb0d191171 (diff) | |
| download | qemu-94054183daffaa41cd77ced9301c01a01027923a.tar.gz | |
qcow2: Optimize bdrv_make_empty()
bdrv_make_empty() is currently only called if the current image
represents an external snapshot that has been committed to its base
image; it is therefore unlikely to have internal snapshots. In this
case, bdrv_make_empty() can be greatly sped up by emptying the L1 and
refcount table (while having the dirty flag set, which only works for
compat=1.1) and creating a trivial refcount structure.
If there are snapshots or for compat=0.10, fall back to the simple
implementation (discard all clusters).
[Applied s/clusters/cluster/ typo fix suggested by Eric Blake
--Stefan]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1414159063-25977-4-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/block/block.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/block/block.h b/include/block/block.h index 341054dcf7..b1f4385f03 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -498,6 +498,8 @@ typedef enum { BLKDBG_PWRITEV_ZERO, BLKDBG_PWRITEV_DONE, + BLKDBG_EMPTY_IMAGE_PREPARE, + BLKDBG_EVENT_MAX, } BlkDebugEvent; |