tree bccf75bc1b4f2268827580f456f55770cc29a93e
parent 13c4941cdd8685d28c7e3a09e393a5579b58db46
author Alberto Garcia <berto@igalia.com> 1431348893 +0300
committer Kevin Wolf <kwolf@redhat.com> 1432307281 +0200

qcow2: use one single memory block for the L2/refcount cache tables

The qcow2 L2/refcount cache contains one separate table for each cache
entry. Doing one allocation per table adds unnecessary overhead and it
also requires us to store the address of each table separately.

Since the size of the cache is constant during its lifetime, it's
better to have an array that contains all the tables using one single
allocation.

In my tests measuring freshly created caches with sizes 128MB (L2) and
32MB (refcount) this uses around 10MB of RAM less.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>