Hi Brandon,

See this discussion for some of the history here:
http://comments.gmane.org/gmane.comp.emulators.m5.devel/30510

Let me try to summarize for everyone.

There are a number of reasons to deprecate/phase out most of the supported
ISAs. Briefly:
 - Less work for contributors especially when updating SE mode
 - Less testing time
 - Some ISAs have no maintainer
 - Some ISAs have (basically) no tests, or the tests are proprietary
 - Causes confusion for users (e.g., they run experiments with an
incomplete ISA, or worse)

However, some people *do* use the code for ISAs other than x86, ARM,
RISC-V, and HSAIL. For instance:
 - From Jakub "[gem5 is] the only existing and basically working open
source sun4v simulator.
 - Boris uses gem5's support for MIPS and POWER to do retargetable compiler
research, and "dropping them would be pretty much equivalent to
discontinuing GEM5 altogether"

I think Steve makes one of the best arguments both for and against this in
this message: http://www.mail-archive.com/gem5-dev@gem5.org/msg19429.html.

-- My opinions below:

From our discussion at HPCA, I think it comes down to "what does the
community want gem5 to be?" Right now, gem5 has a wide variety of different
use cases. I think we need to decide as a community what use cases we want
to support and focus our limited developer time on those use cases. For
instance, do we think it is worth it to support MIPS emulation?

Maybe someone can come up with a list of "gem5 use cases" for us to look at
and discuss. I don't have time in the next week or so, but after that I'll
put it on my to do list.

At a higher level, I strongly believe we need to take a step back and make
sure that gem5 is serving its users as best as it can. There's a lot of
unmaintained code in gem5 that is hurting and not helping. For instance, it
would be great if Brandon could focus his time purely on improving x86 SE
mode, which many people use, and not fixing bugs with SPARC.

Cheers,
Jason

On Thu, Feb 23, 2017 at 4:47 PM Potter, Brandon <brandon.pot...@amd.com>
wrote:

Hello all,

A colleague mentioned that ISA deprecation was discussed during the recent
gem5 meeting. I am wondering what the community's feelings are toward the
idea and which ISAs would be on the chopping block. Personally, I'd like to
kill ALPHA, MIPS, POWER, and SPARC. This means that we'd retain X86, ARM,
RISCV, and HSAIL-X86.

I can help out with the removal if we decide that we want to kill some of
them. We might wait until March 1st to start the process since we're
supposed to transition to fully transition to Git on that day; we could
create a tag for the ISA deprecation in case someone wants to revive one of
them in the future (i.e. MIPS or POWER if someone wants to maintain them).

Regards,
Brandon


_______________________________________________
gem5-dev mailing list
gem5-dev@gem5.org
http://m5sim.org/mailman/listinfo/gem5-dev
_______________________________________________
gem5-dev mailing list
gem5-dev@gem5.org
http://m5sim.org/mailman/listinfo/gem5-dev

Reply via email to