On Wed, Mar 06, 2019 at 05:11:59PM +0100, Nicolas Morey-Chaisemartin wrote: > > > On 3/6/19 11:08 AM, Leon Romanovsky wrote: > > From: Leon Romanovsky <leonro@xxxxxxxxxxxx> > > > > Generalize the naming scheme for RDMA devices, so users will always > > see names based on topology/GUID information. Such naming scheme has > > big advantage that the names are fully automatic, fully predictable > > and they stay fixed even if hardware is added or removed (i.e. no > > reenumeration takes place) and that broken hardware can be replaced > > seamlessly. > > > > The naming policy is possible to chose from NAME_KERNEL, NAME_PCI, > > NAME_GUID or NAME_FALLBACK, which is controlled by udev rule. > > > > * NAME_KERNEL - don't change names and rely on kernel assignment. This > > will keep RDMA names as before. Example: "mlx5_0". > > * NAME_PCI - read PCI location and topology as a source for stable names, > > which won't change in any software event (reset, PCI probe e.t.c.). > > Example: "mlxp0s12f4". > > * NAME_GUID - read system image GUID information in simillar manner to > > net MAC naming policy. Example "mlxx525400c0fe123455". > > * NAME_FALLBACK - automatic fallback: NAME_PCI->NAME_GUID->NAME_KERNEL > > > > No doubts that new names are harder to read than the "mlx5_0" everybody, > > is used to, but being consistent in scripts is much more important. > > > > As a matter of precaution, we set default naming policy to be > > NAME_KERNEL, but will change it later to NAME_FALLBACK. > > > > You probably should extend udev.md to document this value (with pretty much a copy of your commit message). I will do, just wanted to be sure that we are agree on the implementation. > > Also, not sure coding this value directly into the udev script is the right thing to do. > At least RPM may mess with you file during an update if you change it. > We already have a /etc/rdma with a bunch of stuff. Could we stick in there too ? I did it to be similar to other /usr/lib/udev/rules.d/60-persistent-*.rules files. Users who are needed to overwrite it, are expected to use systemd and create their local rule in /etc/udev/rules.d/. > > It would also be nice if we could rename the associated IPoIB device as well. I was under impression that it is netdev job to give right names for IPoIB devices. > We do have the persistent-ipoib udev rule but it'd probably if they had a name "matching" the IB device by default so in most use case people > do not have to set these rules manually and never have to look which netdev matches which IB device. > If we go with my #2 point, we could add a setting to enable/disable this feature. And make sure that the persistent rule is triggered afterwards so legacy name are not overwritten. It won't be overwritten if I rename 99-persistent-rdma ... to be 70-persistent-rdma ... Thanks > > Nicolas >
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