Skip to contentSkip to conversation

Swap space limitions for Linux on parisc

parisc-linux Duraid Madina 3 participants 5 messages Mar 9, 2002

lore
Share & tools
lore
#0 lore raw
Quoted 3 lines · John

P.S. Note that we don't support 64 bit user space processes yet, so you would probably find it difficult to consume extreme amounts of swap space, since each process can only address ~4Gb of memory.

(!!!)

*ponders tearing up his code into multiple processes*

The 'yet' above gives me hope; will 64 bit user space processes be supported anytime soon? Being able to malloc(1<<36) would be nice!

Duraid

#1 lore raw
Quoted 2 lines

The 'yet' above gives me hope; will 64 bit user space processes be supported anytime soon? Being able to malloc(1<<36) would be nice!

I sure hope not.... there is a lot of work involved to bring up toolchains and all the applications to support two different userlands. We still have a lot of work to do just to stablize 32-bit userspace. Check the list archives, this has been discussed before, and once fairly recently.

This is not to say it couldn't be done of course. This is GNU/Linux, you have all the source, go nuts.. :-)

But now you have me curious, what app are you writing that needs >4G of address space?

randolph

Signature · 4 lines
   @..@                                         http://www.TauSq.org/
  (----)
 ( >__< )
 ^^ ~~ ^^
#2 lore raw
Quoted 8 lines
Quoted 2 lines

The 'yet' above gives me hope; will 64 bit user space processes be supported anytime soon? Being able to malloc(1<<36) would be nice!

I sure hope not.... there is a lot of work involved to bring up toolchains and all the applications to support two different userlands. We still have a lot of work to do just to stablize 32-bit userspace. Check the list archives, this has been discussed before, and once fairly recently.

I had a bit of a peek around the archives, wow, I guess hppa64 isn't the most 'comfortable' place for a g++ developer just now.

Quoted 2 lines

This is not to say it couldn't be done of course. This is GNU/Linux, you have all the source, go nuts.. :-)

Project deadline soon :( must.. find.. cheap.. 64 bit machine

Quoted 2 lines

But now you have me curious, what app are you writing that needs >4G of address space?

A computational physics code. Ideally I would run it in 100s of GB of RAM. About two months of pain went into making it work (reasonably efficiently, in theory at least) in 100s of GB of swap.

Now you have *me* curious; I don't mean to be an ignorant asshole, but what's the point of hppa64 if you *don't* support >4G address space?

*crying* does HP-UX support >4G address space? *finds wallet* :( Hmm, probably have to shell out more $$$ for the HP compilers too :\

Duraid

#3 lore raw
Quoted 3 lines · Duraid Madina

A computational physics code. Ideally I would run it in 100s of GB of RAM. About two months of pain went into making it work (reasonably efficiently, in theory at least) in 100s of GB of swap.

Hmm. You would probably be best off making it work by mmaping chunks of a data file at a time.

Quoted 2 lines

Now you have *me* curious; I don't mean to be an ignorant asshole, but what's the point of hppa64 if you *don't* support >4G address space?

Supporting >4GB of physical ram, which can be shared among multiple processes, each being <4GB in size :-)

Quoted 2 lines

*crying* does HP-UX support >4G address space? *finds wallet* :( Hmm, probably have to shell out more $$$ for the HP compilers too :\

gcc works fine on hpux...

Signature · 1 line
Revolutions do not require corporate support.
#4 lore raw
Quoted 2 lines

Hmm. You would probably be best off making it work by mmaping chunks of a data file at a time.

Doing "all that mmap stuff" is what I hoped I could avoid by throwing some $$$$ at a 64-bit machine, and using swap "gently". So HP's new, affordable PA-8700 machines look(ed) terrific.

Quoted 2 lines

Supporting >4GB of physical ram, which can be shared among multiple processes, each being <4GB in size :-)

I know, I know, just having a whinge ;)

Quoted 1 line

gcc works fine on hpux...

Hmm.

Duraid