[Info-vax] New filesystem mentioned

[Dave Froble]

On 5/16/2019 1:53 PM, John Reagan wrote:
> On Thursday, May 16, 2019 at 1:43:48 PM UTC-4, Simon Clubley wrote:
>> On 2019-05-16, Dave Froble <davef at tsoft-inc.com> wrote:
>>> On 5/16/2019 10:04 AM, Bob Koehler wrote:
>>>>
>>>>      No, DLM is a separate part of the kernel, which is used by and
>>>>      required by the XQP and such.
>>>
>>> Damn, that brings up another question.  Is the DLM part of the kernel?
>>> I don't know the details of the implementation, but, I'd at least hope
>>> it is not.  That would allow it to be used in any modular type of OS.
>>
>> It is a part of the kernel, but only in so far as there is no other place
>> to put it in the current VMS design. I can't see anything about the VMS
>> DLM which requires direct access to hardware for example.
>>
>> It provides services to the rest of the kernel (and to non-kernel
>> applications). However, I see no reason why the DLM could not just be
>> another task in a microkernel design (for example).
>>
>>> And before anyone mentions parts of the kernel might use the DLM, I'd
>>> guess that might happen.  Doesn't mean anything used by the kernel is
>>> part of the kernel.
>>>
>>
>> In a VMS style monolithic design, it's all part of the kernel.
>>
>> This is because, on VMS, the DLM directly provides services to the rest
>> of the kernel which means the kernel code needs direct and efficient
>> access to the DLM.
>>
>> Think of it less about being part of the kernel and more about whether
>> the DLM has a clean interface to the rest of the kernel (which would
>> make it easier to use elsewhere).
>>
>> Going back to Linux, that's one of the advantages of the Linux module
>> based architecture. It's all part of the kernel, but there are generally
>> reasonably clean interfaces between the various parts of the kernel as
>> a result.
>>
>> Simon.
>>
>> --
>> Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
>> Microsoft: Bringing you 1980s technology to a 21st century world
>
>
>
> SYSENQDEQ (and a few other modules) are in the LOCKING.EXE execlet.  One of many execlets loaded as part of the OS boot.
>

Oh, no, this could degenerate into a discussion about "what is the VMS 
kernel" and that could be a nasty knife fight.

I should shut up now, but let me ask, does getting loaded as part of the 
OS boot indicate that all such modules are part of the kernel?

-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
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