Re: [Maxima-discuss] Large memory allocations on Linux & WSL (Windows Subsystem for Linux)

[Henry B. <hb...@pi...>]

Re: which lisp?

I'm just getting started in this particular direction, so I'm open to suggestions.

When I looked into this problem several years ago, some of the Lisps didn't
even support very large address spaces.  I'm hoping that the situation is
better today.

In the far distant past, I've had experience working with C-based Lisps; I
would imagine that it might be easier to take advantage of all of the
progress on C/C++ over the past 20+ years to get better results even if
the Lisp source code itself hasn't changed very much.

-----Original Message-----
From: Gunter K&ouml;nigsmann <gu...@pe...>
Sent: May 21, 2023 10:05 PM
To: <max...@li...>, Henry Baker <hb...@pi...>
Subject: Re: [Maxima-discuss] Large memory allocations on Linux &amp; WSL (Windows Subsystem for Linux)

Which lisp have you compiled Maxima with? Gcl and clisp aren't particularly memory-efficient (even iv in different places each). Clisp is,but is surprisingly slow.

Kind regards,

   Gunter.


Am 22. Mai 2023 04:11:19 MESZ schrieb Henry Baker <hb...@pi...>:
Mucho thanks, Serge!  Yes, that worked!

Here's my .wslconfig file:
[wsl2]
# Limits VM memory to use no more than 4 GB, this can be set as whole numbers using GB or MB
memory=11GB
# 10GB wasn't big enough, but 11GB works.

And my 8GB object now gets allocated:

Allocating allocsize = 0x200000000 bytes maxobjsize = 0x7fffffffffffffff
a = 0x7fa79c014010 alignment = 16

Apparently, WSL defaults to using only 50% of the total RAM; that can
be modified by the .wslconfig file.

8GB beats the heck out of 4GB, but eventually I'd like to try even bigger
RAM's. Unfortunately, 16GB maxes out my current laptop, but Microsoft
sells a relatively inexpensive ARM-based box which comes with 32GB.


-----Original Message-----
From: serge de marre <sde...@gm...>
Sent: May 21, 2023 3:09 PM
To: Henry Baker <hb...@pi...>
Subject: Re: [Maxima-discuss] Large memory allocations on Linux &amp; WSL (Windows Subsystem for Linux)

Hi Henry, 
It looks like you can configure how much memory the wsl2 VM is using, see here: https://learn.microsoft.com/en-us/windows/wsl/wsl-config#configuration-setting-for-wslconfig
The option 'memory' looks relevant.
 
Serge


On Sun, May 21, 2023, 23:13 Henry Baker <hb...@pi... (mailto:hb...@pi...)> wrote:
Hi all:

I want to be able to test some extremely large Maxima calculations,
so I've been playing with my computer to see how large a memory
space a program could utilize before it started paging itself to death.

I just ran some tests on my current laptop with 16GB of RAM running
WSL2 (Windows Subsystem for Linux) on top of Windows 11.

My tests involved little more than a "Hello World" C program which also
did a large malloc and then initialized the data.

Actually, I used 'aligned_alloc' instead of 'malloc', but I expect that they
both do roughly the same things.

I was able to allocate a single object up to 2^32 *bytes* long (i.e., 4GB),
and this object initialized properly and quite quickly (i.e., no paging).

However, when I tried 2^33 bytes long (i.e., 8GB), the program works, but it
pages like crazy.  But I have 10GB of RAM free, so there should be plenty
of room for an 8GB object completely in RAM in a trivial program like this.

I checked 'prlimit -l', and both the hard &amp;amp; soft limits seem to allow 131072
pages of 'memlock'ed (non-pageable) memory.

However 'ulimit -l' reports a limit of only 65536 pages of memlock'ed
memory. Even after fiddling with /etc/security/limits.conf, I still couldn't
increase the amount that 'ulimit -l' returns.

I'm currently not running a pure Linux on this machine, so I can't tell if
the problem is Linux (Ubuntu) itself, or whether the problem is WSL.

Any thoughts ?



_______________________________________________
Maxima-discuss mailing list
Max...@li... (mailto:Max...@li...)
https://lists.sourceforge.net/lists/listinfo/maxima-discuss