On 26.06.19 11:01, Christophe de Dinechin wrote: > > David Hildenbrand writes: > >> On 20.06.19 00:32, Alexander Duyck wrote: >>> This series provides an asynchronous means of hinting to a hypervisor >>> that a guest page is no longer in use and can have the data associated >>> with it dropped. To do this I have implemented functionality that allows >>> for what I am referring to as waste page treatment. >>> >>> I have based many of the terms and functionality off of waste water >>> treatment, the idea for the similarity occurred to me after I had reached >>> the point of referring to the hints as "bubbles", as the hints used the >>> same approach as the balloon functionality but would disappear if they >>> were touched, as a result I started to think of the virtio device as an >>> aerator. The general idea with all of this is that the guest should be >>> treating the unused pages so that when they end up heading "downstream" >>> to either another guest, or back at the host they will not need to be >>> written to swap. >>> >>> When the number of "dirty" pages in a given free_area exceeds our high >>> water mark, which is currently 32, we will schedule the aeration task to >>> start going through and scrubbing the zone. While the scrubbing is taking >>> place a boundary will be defined that we use to seperate the "aerated" >>> pages from the "dirty" ones. We use the ZONE_AERATION_ACTIVE bit to flag >>> when these boundaries are in place. >> >> I still *detest* the terminology, sorry. Can't you come up with a >> simpler terminology that makes more sense in the context of operating >> systems and pages we want to hint to the hypervisor? (that is the only >> use case you are using it for so far) > > FWIW, I thought the terminology made sense, in particular given the analogy > with the balloon driver. Operating systems in general, and Linux in > particular, already use tons of analogy-supported terminology. In > particular, a "waste page treatment" terminology is not very far from > the very common "garbage collection" or "scrubbing" wordings. I would find > "hinting" much less specific. for example. > > Usually, the phrases that stick are somewhat unique while providing a > useful analogy to server as a reminder of what the thing actually > does. IMHO, it's the case here on both fronts, so I like it. While something like "waste pages" make sense, "aeration" is far out of my comfort zone. An analogy is like a joke. If you have to explain it, it's not that good. (see, that was a good analogy ;) ). -- Thanks, David / dhildenb
