Re: [suse-sparc] 64 bit Kernel 32 bit userland.

From: Alvaro Figueroa (fede2@fuerzag.ulatina.ac.cr)
Date: Mon Feb 18 2002 - 08:01:57 PST

  • Next message: Andrew Hooper: "RE: [suse-sparc] 64 bit Kernel 32 bit userland."

    From: Alvaro Figueroa <fede2@fuerzag.ulatina.ac.cr>
    Date: 18 Feb 2002 10:01:57 -0600
    Message-Id: <1014048117.1920.12.camel@lucy>
    Subject: Re: [suse-sparc] 64 bit Kernel 32 bit userland.
    

    > Stupid Question....

    No it isnt. Quite an interesting topic BTW.

    > But, The kernel uses 64 bit instructions on Sparc Ultras and the user
    > applications use 32 bit instructions, is this because Linux can't support 64
    > bit applications or can applications only access a 32 bit address space?

    This is because, it has been set up this way.

    The kernel does support 64 bit aplications, and aplications can access
    the 64 bit address space, but they need to be compiled[1] as 64 bit
    aplications.

    The reason why this has been set up this way, is because a 64 bit
    userland will be slower that a 32 bit userland, because they need to map
    those _large_ 64 bit adresses. The only cases in which you will need 64
    bit aplications is when you have (for example) a *huge* database.

    I really don't know if there is any adventages in running processes in a
    64 bit userland. You just don't compile stuff in 64 bits because you
    arch will handle them...

    > So
    > how do I know applications I compile are 32 bit or 64 bit?
    > Can someone point me at an explanation of what's going on?

    Using "file". This will show output like
    ELF 32-bit MSB executable, SPARC, version 1, blah, blah

    or

    ELF 64-bit MSB executable, SPARC V9, version 1, blah, blah

    To compile this aplications you need a cross compiler that will do the
    job. As usual, I don't have an idea if SuSE has a package with this
    compiler in it ;)

    [1] Or cross compiled if you will

    -- 
    Alvaro Figueroa
    

    -- To unsubscribe, e-mail: suse-sparc-unsubscribe@suse.com For additional commands, e-mail: suse-sparc-help@suse.com



    This archive was generated by hypermail 2.1.0 : Mon Feb 18 2002 - 07:59:53 PST