Re: [PATCH V1 0/6] fast qom tree get
Steven Sistare <steven.sistare(a)oracle.com> writes:
On 4/9/2025 3:39 AM, Markus Armbruster wrote:
> Hi Steve, I apologize for the slow response.
>
> Steve Sistare <steven.sistare(a)oracle.com> writes:
>
>> Using qom-list and qom-get to get all the nodes and property values in a
>> QOM tree can take multiple seconds because it requires 1000's of individual
>> QOM requests. Some managers fetch the entire tree or a large subset
>> of it when starting a new VM, and this cost is a substantial fraction of
>> start up time.
>
> "Some managers"... could you name one?
My personal experience is with Oracle's OCI, but likely others could benefit.
Elsewhere in this thread, we examined libvirt's use qom-get. Its use of
qom-get is also noticably slow, and your work could speed it up.
However, most of its use is for working around QMP interface
shortcomings around probing CPU flags. Addressing these would help it
even more.
This makes me wonder what questions Oracle's OCI answers with the help
of qom-get. Can you briefly describe them?
Even if OCI would likewise be helped more by better QMP queries, your
fast qom tree get work might still be useful.