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Subject: Re: Memory allocation anomaly.

Author: Dann Corbit

Date: 18:16:36 03/17/05

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On March 17, 2005 at 17:07:15, Robert Hyatt wrote:

>On March 17, 2005 at 14:47:24, Matthew Hull wrote:
>
>>I have two vanilla builds of GNUChess 5.07.  One is in CYGWIN, the other in
>>Linux.  Both are on x86 architecture.  But each allocates hash memory in
>>different volumes.
>>
>>Example command:
>>
>>./gnuchess -s 10000000
>>
>>On Cygwin, this allocates 393216K of hash memory.
>>
>>On Linux, it allocates 327680K
>>
>>What is the reason for this?
>
>Several possibilities.  But first, have you started both programs without the -s
>option to see how big they are, then restarted both with the -s to see the
>difference?

Some other likely differences:

1.  structure packing (since the hash table seems to be an 'entries' count if
the struct is aligned differently it will not be at all surprising if the same
count of structs has different sizes on two machines.

2.  memory page sizes are different (small differences will be explained this
way)



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