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Date: Sun, 23 Jan 2011 20:11:52 -0800
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To: cygwin AT cygwin DOT com
Subject: Re: max memory
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Christopher Faylor wrote:
> Cygwin only uses as much memory as the OS gives it.  It can't
> use a full 2048MB for the heap.
----

Using the /LARGEADDRESSAWARE flag would allow cygwin to access
up to a full 4GB of memory under Win7-64.

Wouldn't that give enough to Cygwin to allow it to give more to the
heap?

There's several 32-bit progs that should have been able to use over 2GB, with even XP being configurable to run with 3GB of user/1GB system space, but this was not very usable due to XP being hobbled to ignore extended memory (available on XEON processors many years back that allowed up to 64G on 32-bit machines).  

With 64-bit OS's User programs can easily be given more than 2G of addr space, but to allow this programs have to be linked with the largeaddressaware flag.
Then 32-bit cygwin could theoretically use up to 4GB of memory.  If that was the case, cygwin should be able to allocate more memory for user space (search firefox's bugdb for that flag for notes on its progress toward getting that switch enabled -- apparently ready but not yet enabled in shipping versions).

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