On Fri, Sep 15, 2023 at 02:49:41PM +0000, Salil Mehta wrote: > I am not aware of any on x86. Maybe we can do it on ARM first and > let other Arch pitch-in their objection later? Afterall, there is > a legitimate use-case in case of ARM. Having mutually exclusive > bits breaks certain use-cases and we have to do the tradeoffs. ... but let's not use that as an argument to delay the forward progress of getting aarch64 vCPU hotplug patches merged. If we want to later propose that Enabled=1 Online-Capable=1 means that the CPU can be hot-unplugged, then that's something that can be added to the spec later, and added to the kernel later. There is no need to go through more iterations of patch sets to add this feature before considering that aarch64 vCPU hotplug is ready to be merged. Like I said in my other email, it's time to stop this "well, if we do this, then we can do that" cycle - stop playing games with what can be done. Delaying merging this code means not only does the maintenance burden keep increasing (because more and more patches accumulate which have to be constantly forward ported) but those who *want* this feature are deprived for what, another year? two years? decades? before it gets merged. So please, stop dreaming up new features. Let's get aarch64 vCPU hotplug that is compliant with the current ACPI spec, merged into upstream. If we _then_ want to consider additional features, that's the time to do it. If you're not prepared to do that, do not be surprised if someone else (such as myself) decides to fork James' work in order to get it merged upstream - and yes, I _will_ do that if these games carry on. I have already started to do that by proposing a patch that is different from what James has to at least get some of James' desired changes upstream - and I will continue doing that all the time that (a) I see that there's a better way to address something in James' patch and (b) I think in the longer term it will reduce the maintenance burden of this patch set. People are getting sick and tired of waiting for this feature. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
