Sufficient L2 cache can noticeably improve the performance when using
large images with frequent I/O.

Previously, unless 'cache-size' was specified and was large enough, the
L2 cache was set to a certain size without taking the virtual image size
into account.

Now, the L2 cache assignment is aware of the virtual size of the image,
and will cover the entire image, unless the cache size needed for that is
larger than a certain maximum. This maximum is set to 1 MB by default
(enough to cover an 8 GB image with the default cluster size) but can
be increased or decreased using the 'l2-cache-size' option. This option
was previously documented as the *maximum* L2 cache size, and this patch
makes it behave as such, instead of as a constant size. Also, the
existing option 'cache-size' can limit the sum of both L2 and refcount
caches, as previously.
Signed-off-by: NLeonid Bloch <lbloch@janustech.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This test tries reopening a qcow2 image with valid and invalid
options. This patch adds l2-cache-entry-size to the set.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Message-id: 3d3b7d2dbfc020deaef60fb58739b0801eb9517c.1517840877.git.berto@igalia.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Tests 080, 130, 137, and 176 simply do not work with compat=0.10 for the
reasons stated there.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Message-Id: <20171123020832.8165-10-mreitz@redhat.com>
[eblake: fix 177 in a separate commit]
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-id: 20180117165420.15946-3-eblake@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Since test 137 make uses of qcow2.py, only local files are supported.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The previous commit removed the last usage of ${tmp} inside the tests
themselves; the only remaining users are sourced by check. So we can now
drop this variable from the tests.
Signed-off-by: NSascha Silbe <silbe@linux.vnet.ibm.com>
Reviewed-by: NBo Tu <tubo@linux.vnet.ibm.com>
Message-id: 1460472980-26319-4-git-send-email-silbe@linux.vnet.ibm.com
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>