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Re: RFC: compile with BWX thus only support EV56 and later CPUs

Dear Michael

It always sad to give up some machines, but if it saves the life of
others for some time longer, it should be ok. Nobody really objected for
almost a year to your proposal. I guess all of the persons behind the 12
alphas counted in the popcon are on this list and at least one would
have raised the voice if a machines of those was concerned.

You mention it eases your work and accelerates the machines supporting
BWX CPU flag, so I think it is a good idea to drop support for older
CPUs and enjoy support for the remaining alpha systems for some time longer.

Thank you for your valuable effort you put in since so long time already.

Regards, Adrian.

On 05.09.14 10:46, Michael Cree wrote:
> There is a discussion on the Linux kernel mailing list that the
> kernel in future will only support architectures that can guarantee
> atomic aligned scalar accesses down to the byte level (at the moment
> the requirement is only for int (32bit) and long (64bit)).  The only
> architecture that does not meet this new requirement is older Alphas
> that do not have the byte-word extension (BWX) CPU instructions, that
> is, EV4, EV45 and EV5. Thus the writing is on the wall that there
> will be no more Linux kernels for these older Alphas.
> It is also notable that the X server has not worked on these older
> Alphas for a number of years.
> Furthermore, I estimate that a majority of the bugs I have fixed in
> the Debian Alpha distribution over the last couple of years could have
> been fixed by compiling with the BWX.  That is, there is growing
> bitrot in the non-BWX support in the toolchain.
> I therefore propose that we switch the all compilers in Debian-Alpha
> to start compiling with the BWX, that is, we henceforth only support
> EV56 and later CPUs.  That will provide two primary benefits: more
> efficient code and fewer bugs to fix.
> I have been giving consideration to giving up maintaining the Alpha
> port as soon as Jessie is released because of the amount of work in
> keeping the toolchain working.  Dropping non-BWX support might just
> tip the balance for me to continue working on Alpha for a bit longer.
> Thoughts?  Objections to my proposal?
> Cheers
> Michael.

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