Mailinglist Archive: opensuse (3644 mails)

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Re: [SLE] viRtual ram
  • From: Dave Smith <Dave.Smith@xxxxxx>
  • Date: Wed, 6 Mar 2002 14:13:50 +0000
  • Message-id: <20020306141350.GE8191@xxxxxxxxxxxxxx>
On Wed, Mar 06, 2002 at 01:40:22PM +0000, fountai@xxxxxxxxxxxxxxx wrote:
On Wednesday 06 March 2002 12:42 pm, you wrote:
Technically, it must be possible for the system to dump a core file
(of your memory) to swap.

Er, why? If a system wants to dump a core, some pages of that core might come
from physical memory and some might come from swap space. Those pages move,
in ordered sequence, from virtual RAM into a file on the disk. As each is
written out the memory it used can be reclaimed. What might have to happen
that would cause all the pages of a core dump to end up in swap?

This used to be a feature on SunOS - if the system crashed (i.e. kernel
panic or something similar), it would dump the entire contents of memory to
the swap partition, for later debug. If the swap partition was not big
enough, it would start overwriting the next partition on the disk. I believe
this feature has now been removed/fixed, however.

For pre-2.4 kernels, there has been no reason for swap > physical ram.
However, ISTR that recent changes to the VM subsystem have required larger
amounts of swap to be available; mails from Linus to the linux-kernel mail
list have confirmed this. Have a trawl around the web.


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