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I'm sure I could > model my uAPI to be rdma uAPI compliant (I can define proprietary uAPI > there as well), but this doesn't mean I belong there, right ? You sure can, but there is still an expectation, eg in RDMA, that your device has a similarity to the established standards (like roce in habana's case) that RDMA is geared to support. I think the the most important thing to establish a new subsystem is to actually identify what commonalities it is supposed to be providing. Usually this is driven by some standards body, but the AI/ML space hasn't gone in that direction at all yet. We don't need a "subsystem" to have a bunch of drivers expose chardevs with completely unique ioctls. The flip is true of DRM - DRM is pretty general. I bet I could implement an RDMA device under DRM - but that doesn't mean it should be done. My biggest concern is that this subsystem not turn into a back door for a bunch of abuse of kernel APIs going forward. Though things are better now, we still see this in DRM where expediency or performance justifies hacky shortcuts instead of good in-kernel architecture. At least DRM has reliable and experienced review these days. 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Kernel. Org" , dri-devel , Jiho Chu , Yuji Ishikawa Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, Aug 04, 2022 at 10:43:42AM +0300, Oded Gabbay wrote: > After all, memory management services, or common device chars handling > I can get from other subsystems (e.g. rdma) as well. I'm sure I could > model my uAPI to be rdma uAPI compliant (I can define proprietary uAPI > there as well), but this doesn't mean I belong there, right ? You sure can, but there is still an expectation, eg in RDMA, that your device has a similarity to the established standards (like roce in habana's case) that RDMA is geared to support. I think the the most important thing to establish a new subsystem is to actually identify what commonalities it is supposed to be providing. Usually this is driven by some standards body, but the AI/ML space hasn't gone in that direction at all yet. We don't need a "subsystem" to have a bunch of drivers expose chardevs with completely unique ioctls. The flip is true of DRM - DRM is pretty general. I bet I could implement an RDMA device under DRM - but that doesn't mean it should be done. My biggest concern is that this subsystem not turn into a back door for a bunch of abuse of kernel APIs going forward. Though things are better now, we still see this in DRM where expediency or performance justifies hacky shortcuts instead of good in-kernel architecture. At least DRM has reliable and experienced review these days. Jason