[Info-vax] New filesystem mentioned

[VAXman- at SendSpamHere.ORG]

In article <qbk7gi$2j1$1 at dont-email.me>, Simon Clubley <clubley at remove_me.eisner.decus.org-Earth.UFP> writes:
>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.

.... but it does need to communicate with other cluster members to share
the locking information and that is implemented via a cluster SYSAP.

>> 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.

The kernel DOES use the DLM and there are special ENQ/DEQ "APIs" for use
in kernel mode.

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