Re: [libvirt] [PATCH 4/7] qemu: conf: Cache domCaps in qemuCaps
On 4/5/19 1:37 AM, Cole Robinson wrote:
qemuCaps is tied to a binary on disk. domCaps is tied to a combo
of binary+machine+arch+virttype values. For the qemu driver this almost
entirely translates to a permutation of qemuCaps though
Upcoming patches want to use the domCaps data store at XML validate
time, but we need to cache the data so we aren't repeatedly
regenerating it.
Add a domCapsCache hash table to qemuCaps. This ensures that the domCaps
cache is blown away whenever qemuCaps needs to be regenerated. Adjust
virQEMUDriverGetDomainCapabilities to search the cache and add to it
if we don't find a hit.
Signed-off-by: Cole Robinson <crobinso(a)redhat.com>
---
src/qemu/qemu_capabilities.c | 11 +++++++
src/qemu/qemu_capabilities.h | 1 +
src/qemu/qemu_conf.c | 59 +++++++++++++++++++++++++++++++-----
3 files changed, 64 insertions(+), 7 deletions(-)
At first I was affraid, I was petrified, that we will need to invalidate
this cache whenever corresponding qemuCaps is invalidated. But that
should be done automatically, because virQEMUCapsCacheLookup() unrefs
qemuCaps when if finds outdated capabilities.
Might be worth mentioning in the commit message. Or not. Your call.
Michal