[Info-vax] System parameters (and a marketing suggestion), was: Re: What Will Drive More OpenVMS Adoption?

[Arne Vajhøj]

On 12/8/2021 6:46 AM, Johnny Billquist wrote:
> On 2021-12-06 19:45, Arne Vajhøj wrote:
>> On 12/6/2021 1:29 PM, Simon Clubley wrote:
>>> On 2021-12-03, Arne Vajhøj <arne at vajhoej.dk> wrote:
>>>> On 12/3/2021 1:55 PM, Simon Clubley wrote:
>>>>> I think VSI have done some work with parameter defaults so at least
>>>>> some of them will not be an issue on x86-64 VMS.
>>>>>
>>>>> Is there any option in VMS where, if a system/process goes past some
>>>>> percentage (say 80% to 90%) of any system parameter designed to limit
>>>>> use of a resource, VMS will issue an OPCOM warning about that system
>>>>> parameter (and maybe log it elsewhere as well) ? If not, would this
>>>>> be a good option to add to VMS ?
>>>>
>>>> I think VSI should get rid of >95% of SYSGEN and SYSUAF limits.
>>>>
>>>> They made sense with a 256 KB VAX but not so much on a 256 GB x86-64.
>>>
>>> Agreed, but it would be nice if they would retain an overall ability
>>> to stop a single runaway process from gobbling up all the resources
>>> without at the same time having to micromanage resources as needed to
>>> be done on the resource limited systems of old.
>>
>> Sure. But if we have a MAXCPU, a MAXMEMORY and a MAXOPENFILES
>> then how much more do we need.
> 
> Well, there is certainly a big difference between max physical memory 
> allowed, and max virtual memory.

True. I was thinking physical.

But if necessary MAXPHYSMEM and MAXVIRTMEM.

The current number of WS parameters seems excessive.

> And you probably want to have a reasonable working set at all times. And 
> if you go below some lower threshold, you probably don't want to 
> schedule the process, but instead wait until some more resources are 
> available. And meanwhile maybe swap out whatever is in there to free up 
> more resources for others.

But does this need to be configurable and tunable or could we just leave
that to the OS?

I am advocating to leave it to the OS.

> And what does maxcpu mean? You're only allowed to use this much of a CPU 
> no matter how idle it is?

That is usually a blocker of code going into infinite loop or
crazy stuff so yes.

Arne