qcow2: mark the memory as no longer needed after qcow2_cache_empty()
commit355ee2d0e8ca536a6278c9c763ddd2f136eace3f
authorAlberto Garcia <berto@igalia.com>
Tue, 4 Aug 2015 12:14:39 +0000 (4 15:14 +0300)
committerMax Reitz <mreitz@redhat.com>
Fri, 4 Sep 2015 19:00:32 +0000 (4 21:00 +0200)
tree1c7ef0bb90784bb806bc54c04c62f0fb33524520
parent2ef6093cd6990314304f2d3b18eb476ee418d73c
qcow2: mark the memory as no longer needed after qcow2_cache_empty()

After having emptied the cache, the data in the cache tables is no
longer useful, so we can tell the kernel that we are done with it. In
Linux this frees the resources associated with it.

The effect of this can be seen in the HMP commit operation: it moves
data from the top to the base image (and fills both caches), then it
empties the top image. At this point the data in that cache is no
longer needed so it's just wasting memory.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 08538b098e1faf6c92496477cf9b47a20e5aacea.1438690126.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
block/qcow2-cache.c