Messages in this thread | | | Date | Tue, 01 Jun 2004 08:47:19 +1000 | From | Nick Piggin <> | Subject | Re: why swap at all? |
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John Bradford wrote: > Hi, > > Quote from Michael Brennan <mbrennan@ezrs.com>: > >>Hi! >>I've recently started to follow this list. >>I read the swap discussion here, and I was wondering about what Nick >>Pigging said about grepping the kernel tree. >> >>Nick Piggin wrote: >> > For example, I have 57MB swapped right now. It allows me to instantly >> > grep the kernel tree. If I turned swap off, each grep would probably >> > take 30 seconds. >> >>Are the pages swapped to disk as a result of the grep run? >
The pages are gradually swapped to disk as I use the system. > > I'm not really sure what the above was intended to demonstrate, but I assume > that it was that having swap allowed the first grep to fill physical RAM with > cache at the expense of swapping other processes, which were using physical > RAM to disk. >
Well, at the "expense" of paging out unused memory. I don't see any swapin.
> However, if 57 Mb of swap allows this, 57 Mb of extra physical RAM should also > also allow the grep to be cached, without having to swap out anything. >
Well yes, but if I had another 57MB of physical memory then I would still turn on swap so that other 57MB of unused memory isn't wasted. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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