Re: [PATCH v5 3/7] cxl/region: Skip decoder reset on detach for autodiscovered regions

[dan.j.williams]

Koralahalli Channabasappa, Smita wrote:
[..]
> I’m re reading Dan’s note here:
> https://lore.kernel.org/all/6930dacd6510f_198110020@dwillia2-mobl4.notmuch/
> 
> Specifically this part:
> "If the administrator actually wants to destroy and reclaim that
> physical address space then they need to forcefully de-commit that
> auto-assembled region via the @commit sysfs attribute. So that means
> commit_store() needs to clear CXL_REGION_F_AUTO to get the decoder reset
> to happen."
> 
> Today the sysfs commit=0 path inside commit_store() resets decoders 
> without the AUTO check whereas the detach path now skips the reset when 
> CXL_REGION_F_AUTO is set.
> 
> I think the same rationale should apply to the sysfs de-commit path as 
> well? I’m trying to understand the implications of not guarding the 
> reset with AUTO in commit_store().

Linux tends to give the administrator the ability to know better than the
kernel. So if the root forcefully decommits the region, root gets to
keep the pieces.