Re: [libvirt] [PATCH v4 0/2] Add support for qcow2 cache
On 09/13/2017 05:21 AM, Liu Qing wrote:
Qcow2 small IO random write performance will drop dramatically if the
l2
cache table could not cover the whole disk. This will be a lot of l2
cache table RW operations if cache miss happens frequently.
This patch exports the qcow2 driver parameter
l2-cache-size/refcount-cache-size, first added in Qemu 2.2, and
cache-clean-interval, first added in Qemu 2.5, in libvirt.
Change since v3: a) copy qcow2 cache configurion from source to backing
to backing file source.
The difference you list doesn't make any sense. The only difference
between this an V3 is removing the qemu_command.c from patch1. I did a
git diff between the two trees I have from your patches:
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index c3b81e138..e95683965 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -14318,11 +14318,6 @@
qemuDomainSnapshotDiskDataCollect(virQEMUDriverPtr driver,
if (!(dd->src = virStorageSourceCopy(snap->def->disks[i].src,
false)))
goto error;
- /* keep the qcow2 cache configuration */
- dd->src->l2_cache_size =
vm->def->disks[i]->src->l2_cache_size;
- dd->src->refcount_cache_size =
vm->def->disks[i]->src->refcount_cache_size;
- dd->src->cache_clean_interval =
vm->def->disks[i]->src->cache_clean_interval;
-
if (virStorageSourceInitChainElement(dd->src, dd->disk->src,
false) < 0)
goto error;
I'll stick with the v3 version and adjustments from comments that I made.
John
Liu Qing (2):
conf, docs: Add qcow2 cache configuration support
qemu: add capability checking for qcow2 cache configuration
docs/formatdomain.html.in | 43 ++++++++++
docs/schemas/domaincommon.rng | 35 ++++++++
src/conf/domain_conf.c | 95 +++++++++++++++++++++-
src/qemu/qemu_capabilities.c | 9 ++
src/qemu/qemu_capabilities.h | 3 +
src/qemu/qemu_command.c | 33 ++++++++
src/qemu/qemu_driver.c | 5 ++
src/util/virstoragefile.c | 3 +
src/util/virstoragefile.h | 6 ++
tests/qemucapabilitiesdata/caps_2.5.0.x86_64.xml | 3 +
.../caps_2.6.0-gicv2.aarch64.xml | 3 +
.../caps_2.6.0-gicv3.aarch64.xml | 3 +
tests/qemucapabilitiesdata/caps_2.6.0.ppc64le.xml | 3 +
tests/qemucapabilitiesdata/caps_2.6.0.x86_64.xml | 3 +
tests/qemucapabilitiesdata/caps_2.7.0.s390x.xml | 3 +
tests/qemucapabilitiesdata/caps_2.7.0.x86_64.xml | 3 +
tests/qemucapabilitiesdata/caps_2.8.0.s390x.xml | 3 +
tests/qemucapabilitiesdata/caps_2.8.0.x86_64.xml | 3 +
tests/qemucapabilitiesdata/caps_2.9.0.ppc64le.xml | 3 +
tests/qemucapabilitiesdata/caps_2.9.0.s390x.xml | 3 +
tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml | 3 +
.../qemuxml2argv-disk-drive-qcow2-cache.args | 28 +++++++
.../qemuxml2argv-disk-drive-qcow2-cache.xml | 43 ++++++++++
tests/qemuxml2argvtest.c | 4 +
.../qemuxml2xmlout-disk-drive-qcow2-cache.xml | 43 ++++++++++
tests/qemuxml2xmltest.c | 1 +
26 files changed, 386 insertions(+), 1 deletion(-)
create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-drive-qcow2-cache.args
create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-drive-qcow2-cache.xml
create mode 100644 tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-drive-qcow2-cache.xml