Using GCC/GAS Xenix on AT&T Unix V/386.3.2

[John C. Archambeau]

glenn at extro.ucc.su.OZ.AU (Glenn Geers) writes:
>From article <2459 at crash.cts.com>, by jca at pnet01.cts.com (John C. Archambeau):
>> bill at bilver.UUCP (Bill Vermillion) writes:
>>>In article <2413 at crash.cts.com> jca at pnet01.cts.com (John C. Archambeau) writes:
>>>>dlucy at tropez.UUCP (Doug Lucy) writes:
>>>>>I'm using GNU's gcc 1.37.1 and gas 1.35 patched and compiled for
>>>.....
>>>>It should work since SCO Unix is binary compatable with SCO Xenix.  Just don't
>>>>expect the demand paging to kick in on Xenix processes.  I believe you need a
>>>>smarter linker such as the one for the SCO Unix Development System to have the
>>>>demand paging work at all.
>>>
>>>If I am interpreting (or reading between the lines properly) you are saying
>>>that the Development system doens't support creation of demand paged programs
>>>in Xenix even though the OS does.
>>>
>>>I thought the paging was a function of the os and not the linkers.
>>>
>>>Or am I totally confused.
>> 
>> Maybe I am as well.  My understanding is that the linker has to link up the
>> code in such a way that it can be swapped or demand paged.  Keep in mind that
>> I am only familiar with systems that only do swapping, not demand paging and
>> if Xenix 386 does do it, I obviously have overlooked it.  The only process
>> that I see running is the swapper when I do a ps, of course, on systems that
>> do demand paging, it has to be really loaded to kick in.
>> 
>> Again, I may be completely wrong...and if I stuck my keyboard in my mouth, my
>> apologies.
>
>Xenix 386 *DOES* demand page. If it didn't how could I run processes larger
>than physical memory ? I have 3640kb available - subtract ~1Mb for the kernel
>leaving 2640kb but my maximum process size is ~4500kb.
>Why doesn't someone just do vmstat -s and look at the pagein/out stats that are
>provided ?

Maybe I'd better refine the question, what's the difference between ordinary
swapping and demand paging?  I've heard of systems having both and the demand
pager kicking in when the swapper is heavily loaded.  Or am I listening to
misinformation?
 
     // JCA

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