[libvirt] [PATCH] qemu: Exit on first error in qemuDomainGetMemoryParameters

[Matthias Bolte]

2010/10/20 Daniel Veillard <veillard at redhat.com>:
> On Wed, Oct 20, 2010 at 02:37:53PM +0200, Matthias Bolte wrote:
>> There is no point in trying to fill params beyond the first error,
>> because when qemuDomainGetMemoryParameters returns -1 then the caller
>> cannot detect which values in params are valid.
>> ---
>
>  Okay ACK

Thanks, pushed.

>> There is a similar pattern in qemuDomainSetMemoryParameters that tries
>> to apply all given params even if one already failed. From a user's
>> POV it's probably better to apply all params without an error or to
>> apply non at all when one fails. But this is harder to implemeneted
>> and requires a rollback mechanism.
>
>  Well I don't think we can implement transactions there, so there will
> always a case for uncertainties. Still since the client may want to tune
> his guest domain, maybe some of the tuning will fail (and with the
> current API, only retrying with one setting at a time can allow to
> isolate the problem), but after the call we get closer to the expected
> setup. It's still possible to see what was done with the Get API though.
>  The simplest way from a client perspective is probably to change
> only one setting at a time, it's also likely to match the UI offered
> to the end user.
>
> Daniel
>

Okay, that makes sense.

Matthias