Re: No swap can be dangerous (was Re: swap on RAID (was Re: swp - Re: ext3 journal on software raid))

[Andrew Walrond]

On Thursday 06 January 2005 23:15, Guy wrote:
> If I MUST/SHOULD have swap space....
> Maybe I will create a RAM disk and use it for swap!  :)  :)  :)

Well, indeed, I had the same thought. As long as you could guarantee that the 
ram was of the highmem/non-dmaable type...

But we're getting ahead of ourselves. I think we need an authoritive answer to 
the original premise. Perhaps Alan (cc-ed) might spare us a moment?

Did I dream this up, or is it correct?

"I think the gist was this: the kernel can sometimes needs to move bits of 
memory in order to free up dma-able ram, or lowmem. If I recall correctly, 
the kernel can only do this move via swap, even if there is stacks of free 
(non-dmaable or highmem) memory."

Andrew
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