Hi managers,
If the system use the default strategie for swap space
(Inmediate Mode , "Eager"), swap space is reserved or
allocated when modifiable virtual address space is
created.
Below, I'm quoting the reply from Peter Chapin, as the summary.
Peter Chapin wrote:
"
Many applications ask for (virtual) memory without actually ever using it.
When the system is configured for "eager" allocation (the default), it
will reserve space in the swap partition for all virtual memory required
even if it is never actually used. That way should any application ever
try to use any of the memory it thinks it has allocated, the usage will
succeed.
The problem with this approach is that it eats up your swap partition with
with allocations that don't really matter most of the time. If you switch
the kernel to "lazy" allocation mode it takes a different approach. In
that case, the virtual memory allocated is only that which is actually
used. The bad part about that is if the system runs out of virtual memory
resources, an application will fail even though its earlier request for
memory was "successful". Applications aren't necessarily prepared for
that and may die ungracefully."
Many thanks to :
Tom Blinn
Alan NAbeth
Colin Walters, who pointed me to the on line " System Configuration
and Tuning" Manual ( for DU4.0D, Chapter 4, paragraph 4.6.3)
Robert Fridman
Abdon Tremols
Calvin Coghlan
Peter Chapin
Richard TAmes
Ada
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Received on Thu Feb 08 2001 - 14:50:23 NZDT