How FreeBSD manage more than 4GB on 32 bits architecture
freebsd at qeng-ho.org
Thu Apr 9 13:11:08 UTC 2015
On 09/04/2015 11:00, Pierre-Yves Péneau wrote:
> On 04/09/2015 11:49 AM, Ralf Mardorf wrote:
>> On Thu, 9 Apr 2015 11:49:41 +0200, Eduardo Morras wrote:
>>> You are looking for PAE.
>> PAE does not support up to 8TB as the OP mentions. PAE is limited
>> to 64 GiB.
> Sorry, I forgot something important. My physical memory is 1TB, and as
> Ralf said, PAE is limited to 64GB (36 bits). I'm looking for a 40 bits
> support (at least).
I've just realised the original post said
> According to the architecture handbook(*), "FreeBSD could
> theoretically handle memory configurations up to 8TB on a 32 bit
Having followed the link, I find that's a partial quote, and the full
"In fact, if the mmu were capable of it, FreeBSD could theoretically
handle memory configurations up to 8TB on a 32 bit platform. However,
since most 32 bit platforms are only capable of mapping 4GB of ram, this
is a moot point."
I.e. it was talking about the software architecture of the kernel
virtual memory manager on 32 bit processors, not the hardware.
Those who do not learn from computing history are doomed to
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