LiveCD patch for low-memory systems (192K)

[John McCabe-Dansted]

On Sat, Mar 8, 2008 at 4:20 PM, Alexandre Strube <surak at ubuntu.com> wrote:
>  if we have ram in the first place, why should we swapping and
>  compressing the swap back into ram again? I mean, if you can store the
>  swap in ram, is that you have space, so you didn't even need to swap,
>  no?

Because we can fit twice as many compressed pages in ram as uncompressed.

>  >  PROS:
>  >  P1: Much faster
>  >    (zero latency and decompression can be 25% as fast as memcpy)
>  >  P2: No need for swap partition.
>
>  Up to when? There will be a moment when the space reserved for it will
>  finish, no?

Yes. We can increase effective size of memory by about 50% before
needing physical swap.

>  >  CONS:
>  >  C1: Requires Memory.
>
>  Wasn't it EXACTLY for machines without enough ram for running ubuntu normally?

Yes. Again requiring 2K of memory is better than requiring 4K of
memory per page.

>  >  C3: Places more load on CPU
>
>  What is the regular use-case for low-memory machines? Well, its OLD
>  machines. And I mean, OLD. Like pentium 133 or so.

For LiveCD I still cannot support machines with less than 128MB of
ram, even on xubuntu. The alternate install cd can be used on machines
with 64MB of memory (but perhaps another distro would be more
approriate.) On 128MB machines 600MHz cpus are common.

Anyway pentium 133 wasn't low CPU; indeed, the pentium 66 was the
latest and greatest in 1993 when the seminal work "The compression
cache: Using on-line compression to extend physical memory," was
published.

Compressed Caching can improve performance on pentium 133's, even
where physical swap is availiable. See:
  http://linuxcompressed.sourceforge.net/linux24-cc/statistics/0.21_memtest/
(This uses WKdm which is not yet supported by compcache-0.2)

It's amazing what you can do with an Intel pentium [133] processor: ;)
  http://www.youtube.com/watch?v=566ME4nOgRw

>  >  C3 is less important than P4 on new desktops as DualCore single HDD
>  >  machines are now the norm. However in my testing of LiveCD in VMs I
>
>  HA! In YOUR country. Please don't generalize.
>
>  Serious, if you have little ram, it's well possible that you have a
>  low cpu as well. So I don't get the point of this.

Generally, In countries where it new desktops are the norm, DualCores
are the norm.

In any case, planning for the future means planning for multiple core CPUs.

On Sat, Mar 8, 2023 at 4:20 PM, Alexandre Strube <surak at ubuntu.com> writes:
> And I mean, OLD. Like pentium OctCore or so.

Quite ;)

>  By the way, what does it mean the (192K) at the subject?

The patch is a 192K download.

-- 
John C. McCabe-Dansted
PhD Student
University of Western Australia