Re: [libvirt] [PATCH 1/2] conf: add disk cache tuning parameters after qemu

On 26.09.2016 13:04, Peter Krempa wrote: > On Mon, Sep 26, 2016 at 12:15:42 +0300, Nikolay Shirokovskiy wrote: >> On 26.09.2016 12:01, Peter Krempa wrote: > > [...] > >> Sorry, I forget to write down the motivation. >> >> Internally qemu uses 3 orthogonal flags to configure disk cache. They >> are exposed in interface too quite long time ago (29c4e2b). All-in-one >> cache parameter that libvirt uses now do not provide all possible >> values (5 vs 8). For example absent combination of direct + no flush (no sync) >> is useful to speed up tests. > > Well, if there are useful combinations we can add them to the existing > cache setting. > >> So I decided to provide new possibilities just as qemu does - keep >> old parameter and use new ones to tune over. > > I don't think this is a good idea at all. It's very qemu specific and > can be mapped to existing elements. > > Peter > Well up until now libvirt cache settings are exactly the same as the qemu ones. I thought it would be inconsistent to intordocuce new name and then map internallly to qemu. Another point is that these 3 parameters are probably not that qemu specific. Nikolay -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list