On Fri, Aug 16, 2024 at 11:51:17 +0800, Chun Feng Wu wrote: > > On 2024/8/15 13:04, Chun Feng Wu wrote: > > > > On 2024/8/9 22:04, Peter Krempa wrote: > > > On Wed, Jun 12, 2024 at 03:02:17 -0700,wucf@xxxxxxxxxxxxx wrote: > > > > From: Chun Feng Wu<wucf@xxxxxxxxxxxxx> [...] > > > I'd strongly prefer if you modify this such that the trottle layers will > > > be instantiated at per-storage-source level both in XML and in the code. > > > > regarding per-storage-source, do you mean xml like below? if so, when > > specifying "--throttle-groups" in "attach-disk" > > > > it apply groups on top source(vm1_disk_2.qcow2) only? is there scenario > > to apply throttle-groups on backing store source? > > > > <disk type='file' device='disk'> > > <driver name='qemu' type='qcow2'/> > > <source file='/virt/disks/vm1_disk_2.qcow2' index='1'> > > <throttlefilters> > > <throttlefilter group='limit0'/> > > </throttlefilters> > > </source> > > <backingStore type='file' index='4'> > > <format type='qcow2'/> > > <source file='/virt/disks/backing.qcow2'> > > <throttlefilters> > > <throttlefilter group='limit1'/> > > </throttlefilters> > > </source> > > <backingStore/> > > </backingStore> > > <target dev='vdc' bus='virtio'/> > > <alias name='virtio-disk2'/> > > <address type='pci' domain='0x0000' bus='0x00' slot='0x06' > > function='0x0'/> > > </disk> > and regarding code part for per-storage-source, do you mean preparing > throttle filter chain json within > "qemuBuildStorageSourceChainAttachPrepareBlockdev(virStorageSource *top)"? > if so, current "qemuBuildStorageSourceChainAttachPrepareBlockdev" doesn't > include copy-on-read layer, however, throttlefilter chain depends on it for Yeah, this would necessarily mean that copy-on-read is on top of the throttle layer. > top source, in that case, should preparation of copy-on-read be moved into > "qemuBuildStorageSourceChainAttachPrepareBlockdev" as well? if yes, current No. There's no sense to have multiple copy-on-read layers. > parameter "virStorageSource *top" is not enough, also, do you see any > concern about updating "qemuBuildStorageSourceChainAttachPrepareBlockdev" > for throttle chain, it seems it has a lot of callers As I've said in previous reply, having it on per-node level may be overkill. If you don't ever forsee to use this differently then maybe let's stick to the per-disk config, by just keeping proper ordering and remembering the node names.
