On Tue, 22 May 2018, Dan Williams wrote: > >> Except I'm being responsive. > > > > Except you're looking to immediately punt to linux-arm-kernel ;) > > Well, I'm not, not really. I'm saying drop ARM support, it's not ready. This is the worst thing to do - because once late cache flushing is dropped from the dm-writecache target, it could hardly be reintroduced again. > >> I agree with Christoph that we should > >> build pmem helpers at an architecture level and not per-driver. Let's > >> make this driver depend on ARCH_HAS_PMEM_API and require ARM to catch > >> up to x86 in this space. We already have PowerPC enabling PMEM API, so > >> I don't see an unreasonable barrier to ask the same of ARM. This patch > >> is not even cc'd to linux-arm-kernel. Has the subject been broached > >> with them? > > > > No idea. Not by me. > > > > The thing is, I'm no expert in pmem. You are. Coordinating the change > > with ARM et al feels unnecessarily limiting and quicky moves outside my > > control. > > > > Serious question: Why can't this code land in this dm-writecache target > > and then be lifted (or obsoleted)? > > Because we already have an API, and we don't want to promote local > solutions to global problems, or carry unnecessary technical debt. > > > > > But if you think it worthwhile to force ARM to step up then fine. That > > does limit the availability of using writecache on ARM while they get > > the PMEM API together. > > > > I'll do whatever you want.. just put the smack down and tell me how it > > is ;) > > I'd say just control the variables you can control. Drop the ARM > support if you want to move forward and propose extensions / updates What do we gain by dropping it? > to the pmem api for x86 and I'll help push those since I was involved > in pushing the x86 pmem api in the first instance. That way you don't > need to touch this driver as new archs add their pmem api enabling. The pmem API is x86-centric - that the problem. Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
