[Linux-ia64] binary kernel module build flags

[Linux-ia64] binary kernel module build flags

[John Kohl]

We're working to port our file system module to Linux-IA64.  Is there
some set of compiler flags which we can use to build object files that
can be linked into modules to work on all IA64 processors?  Do we need
to worry about -ma-step, etc.?

-- 
=John Kohl <jtk@rational.com>, Software Engineer
Rational Software, Configuration Management Business Unit
Mark your calendars!  Rational User Conference 2001, July 22-26, 2001
in beautiful Denver, Colorado

Re: [Linux-ia64] binary kernel module build flags

[Jim Wilson]

You shouldn't worry about A-step or B0-step processors unless you personally
are still using them because you haven't gotten upgrades yet.  I'd like to
eliminate the compiler -ma-step option before gcc3 comes out, which means it
won't be in the next compiler release.  Meanwhile, if you must use A-step or
B0-step processors, then you must use the -ma-step compiler option.  Otherwise,
I recommend using -mb-step for now, which will support B1 and higher processor
steppings.

The current round of OS releases are coming out with B step kernel support only
by default, and A step support is provided with an optional kernel (TurboLinux)
or not at all (Red Hat).

Jim

Re: [Linux-ia64] binary kernel module build flags

[E. Focht]

Please don't drop the A-stepping support too early! Most of our machines
and half of our processors are still A3 step! And they probably won't be
upgraded before February 2001.

> You shouldn't worry about A-step or B0-step processors unless you personally
> are still using them because you haven't gotten upgrades yet.  I'd like to
> eliminate the compiler -ma-step option before gcc3 comes out, which means it
> won't be in the next compiler release.  Meanwhile, if you must use A-step or
> B0-step processors, then you must use the -ma-step compiler option. Otherwise,
> I recommend using -mb-step for now, which will support B1 and higher processor
> steppings.

Why and when do you want to remove the -ma-step option?

> The current round of OS releases are coming out with B step kernel support only
> by default, and A step support is provided with an optional kernel (TurboLinux)
> or not at all (Red Hat).

As far as I understand, Turbolinux boots the uniprocessor kernel on A-step
CPUs but it's config file stored in the configs directory doesn't have
A-stepping support enabled. The beta2 TurboLinux distribution raises
serious problems, one must recompile kernel and toolchain in order to be
able to work without crashing every few minutes on an A3 stepping
CPU. And I'm not using X or GNOME...

Regards,
Erich

Re: [Linux-ia64] binary kernel module build flags

[Uros Prestor]

On Thu, 14 Dec 2000, E. Focht wrote:

> Please don't drop the A-stepping support too early! Most of our machines
> and half of our processors are still A3 step! And they probably won't be
> upgraded before February 2001.

The support for A-stepping processors seriously limits the amount of
optimizations you can do.  It's not just the workarounds in the kernel,
it's also the fact that you can't use optimized memory copy routines, for
example.  You should really work with Intel to get your boxes upgraded.

> As far as I understand, Turbolinux boots the uniprocessor kernel on A-step
> CPUs but it's config file stored in the configs directory doesn't have
> A-stepping support enabled. The beta2 TurboLinux distribution raises
> serious problems, one must recompile kernel and toolchain in order to be
> able to work without crashing every few minutes on an A3 stepping
> CPU. And I'm not using X or GNOME...

The A-step support in Beta2 was included just to help with the
install.  It was not thoroughly tested (we don't have any A-step boxes
anyway).  The config files included with kernel-source are for the regular
kernels.  The only difference for the install kernel was to enable the
A-step workarounds.

You are right that you need to recompile the kernel and the
toolchain.  You should probably recompile the glibc as well (and remove
the optimized memory copy routines).

Uros

Re: [Linux-ia64] binary kernel module build flags

[Jim Wilson]

>Please don't drop the A-stepping support too early! Most of our machines
>and half of our processors are still A3 step! And they probably won't be
>upgraded before February 2001.

If I remove the compiler -ma-step option now, it will be about 3-6 months
before you see it in an OS release.  I believe now is the right time
to drop support for it, as it doesn't make sense for next year's compiler
releases to contain A step processor support.  The current compiler release
will obviously continue to support A step, so this does not effect anyone who
is currently still using A step machines.

Jim