On 2018-12-05 3:58 p.m., Jerome Glisse wrote: > So just to be clear here is how i understand your position: > "Single coherent sysfs hierarchy to describe something is useless > let's git rm drivers/base/" I have no idea what you're talking about. I'm saying the existing sysfs hierarchy *should* be used for this application -- we shouldn't be creating another hierarchy. > While i am arguing that "hey the /sys/bus/node/devices/* is nice > but it just does not cut it for all this new hardware platform > if i add new nodes there for my new memory i will break tons of > existing application. So what about a new hierarchy that allow > to describe those new hardware platform in a single place like > today node thing" I'm talking about /sys/bus and all the bus information under there; not just the node hierarchy. With this information, you can figure out how any struct device is connected to another struct device. This has little to do with a hypothetical memory device and what it might expose. You're conflating memory devices with links between devices (ie. buses). > No can do that is what i am trying to explain. So if i bus 1 in a > sub-system A and usualy that kind of bus can serve a bridge for > PCIE ie a CPU can access device behind it by going through a PCIE > device first. So now the userspace libary have this knowledge > bake in. Now if a platform has a bug for whatever reasons where > that does not hold, the kernel has no way to tell userspace that > there is an exception there. It is up to userspace to have a data > base of quirks. > Kernel see all those objects in isolation in your scheme. While in > what i am proposing there is only one place and any device that > participate in this common place can report any quirks so that a > coherent view is given to user space. The above makes no sense to me. > If we have gazillion of places where all this informations is spread > around than we have no way to fix weird inter-action between any > of those. So work to standardize it so that all buses present a consistent view of what guarantees they provide for bus accesses. Quirks could then adjust that information for systems that may be broken. Logan
