Re: Why 128Mb swap? (Re: Booting to >8GB...)

From: Riley Williams (rhw@MemAlpha.CX)
Date: Sat Apr 29 2000 - 16:45:09 EST

Hi Khimenko.

>>> 1. /dev/hda1 is a Linux Swap partition of just under 128M
>>> (not more than 130,950 blocks) in size, starting at
>>> cylinder 1.

>> Just a question, but why the 128M limit? That's not the limit on
>> memory, so it's not about page allocation. I would gladly create
>> 1*1Gb swap partition, rather than 8*128Mb.

> Long time ago first page of swap contained signature 10 bytes
> long in the end of first page and the rest of that page was
> devoted to bit map (bit 1 == page usable, bit 0 == page
> unusable). First page was thus unavailable as well (there is bit
> map and signature) maxsize=4096*((4096-10)*8-1)=133885952 bytes

> Now (with kernel 2.2 and up) limit is raised to 2146791424
> bytes...

Precicely how is that limit reached? It's not a straight 2^31 as
that's 2,147,483,648 or about 1M larger than the figure you quote.

> I REALLY see no reason to use 8*128MiB swap partitions...

If it has indeed been upped like that, neither do I...

> Perhaps Riley still can not forget about 2.0 compatibility...

To be more accurate, I didn't even know that limit had been raised.
When (ie, which kernel) was that done?

Best wishes from Riley.

 * Famous people 57:
 * Gates, Bill: Head Prophet of the Church of Microsoft.

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