From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds) Subject: Re: 0.97 patchlevel 3 available Date: 7 Sep 1992 08:07:27 GMT
In article <1992Sep6.174044.28957@mo.hobby.nl> hans@mo.hobby.nl (Hans Oey) writes:
>
>Sure, 16 Mb is enough. Jeez, why would people ever need
>more then 640 Kb? Swap partitions give far better
>performance. Should we use up to 128 partitions?
>Please remove this limitation on Linux. Would a beer or
>two help you to find the energy?
Actually, beer-drinking doesn't seem to help programming very much :-)
And as people have been very concerned about the 16MB limit - don't
panic. It's not inherent to anything like the DOS 640kB limit, and is
there just because it was a bit easier to code that way - correcting it
later won't break anything. So while this version and the next may have
this limitation, it will go away (cleanly) - I just have to code some
more.
In case anybody is wondering why there is a 16MB limit in the pl3 code,
it's very simple: I use a character array to store the swap-page-counts,
and that array just happens to be 4096 bytes long, as that's the biggest
easily allocable unit of memory in the current kernel. So I just
allocate 4096 bytes: 4096 swap-page-counters = 16MB swapspace. So the
only thing that I have to do to allow bigger swapfiles is to allocate
more memory - SMOP, but irritating and boring.
Linus