Re: [PATCH 1/4] xen: Introduce non-broken hypercalls for the p2m pool size

[George Dunlap <George.Dunlap@citrix.com>]

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> On 31 Oct 2022, at 09:26, Jan Beulich <jbeulich@suse.com> wrote:
> 
> On 28.10.2022 17:27, George Dunlap wrote:
>> On Thu, Oct 27, 2022 at 8:12 AM Jan Beulich <jbeulich@suse.com> wrote:
>> 
>>> On 26.10.2022 21:22, Andrew Cooper wrote:
>>>> On 26/10/2022 14:42, Jan Beulich wrote:
>>> 
>> 
>> 
>>>> paging isn't a great name. While it's what we call the infrastructure
>>>> in x86, it has nothing to do with paging things out to disk (the thing
>>>> everyone associates the name with), nor the xenpaging infrastructure
>>>> (Xen's version of what OS paging supposedly means).
>>> 
>>> Okay, "paging" can be somewhat misleading. But "p2m" also doesn't fit
>>> the use(s) on x86. Yet we'd like to use a name clearly better than the
>>> previous (and yet more wrong/misleading) "shadow". I have to admit that
>>> I can't think of any other sensible name, and among the ones discussed
>>> I still think "paging" is the one coming closest despite the
>>> generally different meaning of the word elsewhere.
>>> 
>> 
>> Inside the world of operating systems / hypervisors, "paging" has always
>> meant "things related to a pagetable"; this includes "paging out to disk".
>> In fact, the latter already has a perfectly good name -- "swap" (e.g., swap
>> file, swappiness, hypervisor swap).
>> 
>> Grep for "paging" inside of Xen. We have the paging lock, paging modes,
>> nested paging, and so on. There's absolutely no reason to start thinking
>> of "paging" as exclusively meaning "hypervisor swap".
> 
> Just to clarify: You actually support my thinking that "paging" is an okay
> term to use here? I ask because, perhaps merely because of not being a
> native speaker, to me content and wording suggest different things: The
> former appears to support my response to Andrew, while the latter reads to
> me as if you were objecting.

Sorry, the tone was “objecting” because it was directed mainly at Andrew’s arguments.  I thought about replying only to his mail, but it seemed like since I was clearly “joining the discussion”, it would make more sense to quote you too.  I could probably have made it more clear by leading with something like, “I tend to agree with Jan here. …”

 -George


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