Hi Everyone, You have probably all heard my complaining about tests taking /ages/ to run. One way we could reduce overhead (mainly at compile time) would be to retire some of the poorly supported ISAs. This would serve three purposes:
1. It reduces overhead for developers. 2. It reduces the cost of testing if/when we move regression tests to a cloud solution. One of the problems poorly supported architecture pose is that we still need to compile them in three different modes whenever we run regressions. This consumes many cores hours (== money). 3. It reduces confusion among users. Having a handful of architectures that are clearly incomplete and don¹t support full-system is not very helpful to anyone. I would propose that we plan to phase out the architectures based on the following criteria: 1. Completeness: We should phase out ISAS that don¹t support full-system unless there is a clear plan to add that support. (The NULL ISA is an exception) Users expect to be able to run an OS if an ISA is supported. In practice, most ISAs in this category probably lack good SE mode support since they have few or no users. 2. Ecosystem: We should phase out ISAs that don¹t have compiler support. Being able to run code isn¹t very useful if you can¹t compile code for the platform. Using old compilers isn¹t very helpful either since that is /very/ likely going to lead to meaningless performance results. 3. Maintainers: We should /consider/ phasing out ISAs where there is no clear maintainer. Only ISAs with clear maintainers are likely to be even close to functionally correct. Currently, ALPHA, POWER, and MIPS fail at least two of these criteria. SPARC is borderline. You could argue that SPARC fails 1 since OS boot isn¹t normally tested. I would suggest that these architectures are scheduled for a two step phase out. Short term, we phase out POWER and MIPS. They don¹t have clear maintainers or users submitting patches for them and they lack full-system support. They won¹t be missed. Medium to long term, we plan to phase out ALPHA within the next 6 months and phase out SPARC unless someone steps up and want to care for it long-term. For SPARC to stay, it needs to have at least one working full-system test that can be redistributed (i.e., not Solaris). Thoughts or objections? Cheers, Andreas IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. _______________________________________________ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev
