[Info-vax] What would be involved in moving RMS into kernel mode ?

[Stephen Hoffman]

On 2023-05-05 12:22:56 +0000, Simon Clubley said:

> On a more serious note, I've received private email pointing out that 
> there may be an issue with PPFs if running RMS in user mode.

User mode in a different process is (ideally) immune to user mode 
shenanigans in a nefarious process, and anything that needs to be 
protected within the local process can be in a mode inaccessible to 
user mode.

> I also wonder how global buffers might be affected by user-mode RMS.

Either the buffers are mapped and accessible in virtual memory, or not.

(Reducing the numbers of buffer copies has not been a focus for 
OpenVMS. There have been previous discussions here concerning the 
network stack latency, too. 
https://groups.google.com/g/comp.os.vms/c/AAkAPK5_CZ4/m/2RkjDkm2AQAJ )

And there's an open question around how beneficial RMS global buffers 
might be in practice, given current SSD transfer speeds are approaching 
those of DDR3 SDRAM memory. Upgrades from HDDs to SSDs can hide a whole 
lot of app performance issues.

But again, VSI is not in a position to re-architect OpenVMS now, nor in 
the forseeable future.


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