Can anyone explain the exact behaviour (and differences, if any) of
SHARE_MAGIC and DEMAND_MAGIC executables on HP-UX 11iv2 PA-RISC (or point me
to a good Web page)?

So far, I have only been able to find somewhat confusing information about
this.

Java Memory Management on HP- UX
(http://www.hp.com/products1/unix/jav...Management.pdf)
claims that SHARE_MAGIC is also called DEMAND_MAGIC.

HP-UX Solaris to HP-UX Porting Guide
(http://h30097.www3.hp.com/docs/STKS/SOLARIS.HTM) on the other hand says
that with SHARE_MAGIC everything is loaded at startup, while with
DEMAND_MAGIC, pages are loaded as needed.

Linking Programs on HP-UX (http://docs.hp.com/en/B2355-90655/ch02s05.html)
also suggests that there is a difference between SHARE_MAGIC and
DEMAND_MAGIC.

But doing some tests on testdrive.hp.com, it appears that text pages are
only loaded on demand, even for SHARE_MAGIC binaries. My personal guess
would therefore be that in current HP-UX versions there is no difference
between SHARE_MAGIC and DEMAND_MAGIC any more (but there probably was in the
past).

And can I also assume that 64-bit PA-RISC and IA-64 binaries are always
loaded (paged in) on demand?


Christof

--
http://cmeerw.org sip:cmeerw at cmeerw.org
mailto:cmeerw at cmeerw.org xmpp:cmeerw at cmeerw.org

On 19 Nov 2006, NOSPAM-seeMySig+ur85+@usenet.cmeerw.org wrote:

> Can anyone explain the exact behaviour (and differences, if any) of
> SHARE_MAGIC and DEMAND_MAGIC executables on HP-UX 11iv2 PA-RISC (or
> point me to a good Web page)?
>
> So far, I have only been able to find somewhat confusing information
> about this.
>
> Java Memory Management on HP- UX
> (http://www.hp.com/products1/unix/jav...Management.pdf)
> claims that SHARE_MAGIC is also called DEMAND_MAGIC.
>
> HP-UX Solaris to HP-UX Porting Guide
> (http://h30097.www3.hp.com/docs/STKS/SOLARIS.HTM) on the other hand
> says that with SHARE_MAGIC everything is loaded at startup, while
> with DEMAND_MAGIC, pages are loaded as needed.
>
> Linking Programs on HP-UX
> (http://docs.hp.com/en/B2355-90655/ch02s05.html) also suggests that
> there is a difference between SHARE_MAGIC and DEMAND_MAGIC.
>
> But doing some tests on testdrive.hp.com, it appears that text pages
> are only loaded on demand, even for SHARE_MAGIC binaries. My
> personal guess would therefore be that in current HP-UX versions
> there is no difference between SHARE_MAGIC and DEMAND_MAGIC any more
> (but there probably was in the past).
>
> And can I also assume that 64-bit PA-RISC and IA-64 binaries are
> always loaded (paged in) on demand?
>
>
> Christof

Christof,

Despite some documentation to the contrary, there is no difference
between SHARE_MAGIC and DEMAND_MAGIC on HP-UX 11iv2.

Regards,
Carl