Re: MMUless Linux 2.6 for x86

["Carlo J. Calica" <ccalica@xxxxxxxxx>]

This project might be useful:

http://web.yl.is.s.u-tokyo.ac.jp/~tosh/kml or google "kernel mode linux"

It allows user processes to run in kernel mode lowering sycall and context
switch overheads.

MHD.Tayseer Alquoatli wrote:

> On 1/7/06, Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote:
>> On Sat, 2006-01-07 at 13:05 +0100, +BigNose wrote:
>> > Hello,
>> >
>> > I don't know if this is the right place to ask my question. If not,
>> > please tell me where to put the question...
>> >
>> > I read in several places, that Linux 2.6 can be configured with no
>> > Virtual Memory Support. But I couldn't find any such option in the
>> > kernel config. The only option I found was to disable the Swapping.
>> > But not the Virtual Memory System.
> 
> AFAIK there is no option to tell your Linux kernel to ignore VM .. i
> think you are talking about uclinux:
> http://www.uclinux.org/
> which is a port of the Linux kernel to MMUless hardware and to some of
> MMU capable hardware and it's widely used in embedded environments..
> you can check the available port .. but AFAIK there is no port for x86
> as it is an MMU capable hardware
> MHD.Tayseer
> 
>> >
>> > I would like to disable the Virtual Memory System for an embedded
>> > RTAI System, where latency is everything, and task-switching in an
>> > MMU-Environment is slow...
>>
>> I think you have old data; a syscall is 500 cycles nowadays, and a full
>> switch isn't much more than that...
>>
>>
>> (but there is no way to run x86 mmuless, the "2.6 can run without mmu"
>> is about hardware without an mmu ...)
>>
>>
>> --
>> Kernelnewbies: Help each other learn about the Linux kernel.
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>>
>>
> 
> --
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