Re: Breaking /emul/ia32-linux for squeeze
> On Mar 16, Simon Richter <email@example.com> wrote:
>> Well, it would get i386/amd64 in line with sparc/sparc64, powerpc/powerpc64
>> and s390/s390x. That would allow us to get rid of a lot of specianl cases,
>> including the hack for libc6-386.
> I think it would be very helpful if somebody could summarize why a
> multiarch system is useful, except for the obvious case of installing
> proprietary i386 software on amd64 systems.
People who use those systems frequently could probably provide more
cases, but I know of three cases beyond running "qualified" or
"supported" 32-bit binaries on 64-bit systems):
- On platforms where the 32-bit mode is not so register-poor as i386,
using 32-bit binaries can be significantly faster and less
cache-disruptive than 64-bit binaries because they need less memory
bandwidth. Even on amd64 systems, some executables have this trait.
- Some users have code that does not function properly on systems with
sizeof(int) != sizeof(void*). Multiarch gives them a chance to
migrate this code at their own pace.
- For environments with certain configuration management or regulatory
requirements, qualifying new binaries is a considerable cost --
having nothing to do with whether the software is "proprietary" --
and multiarch makes it easier for them also to migrate at a pace
that makes sense to them.