Joshua Hahn <joshua.hahnjy@xxxxxxxxx> writes: > On Wed, 22 Jan 2025 09:37:20 +0800 "Huang, Ying" <ying.huang@xxxxxxxxxxxxxxxxx> wrote: > > Hi Gregory and Ying, thank you both for your insights! > > [...snip...] > >> >> I still prefer to use 2 iw_table, one is for default, the other is for >> >> manual. The default one will be used if the manual one is NULL. Both >> >> are protected by RCU. The default one can be updated upon hotplug >> >> blindly. This makes the whole model easier to be understood IMHO. >> > `cat auto node0 node1` -> `true 5 1` >> > and you do >> > echo 0 > auto > > I think that when initially developing this patch, this was the intent > that I had as well (in the v1 of this RFC patch, there was an iw_table > and a separate default_iw_table). However, I think that the ideas of > having a "default" and "manual" table made less sense over time, given > that they behaved more like a "default" and "visible" table instead. > That is, the visible layer is directly manipulable by the user, but > does not necessarily only contain manually-set values; rather, most of > the time, it probably still has a lot of auto-generated weights. > > I think that this analysis runs the risk of being a bit too semantically > nit-picky, but as I'll explain below, I think both the 1-layer approach > that I implemented in this RFC and the expected 2-layer behavior that > you outline below are essentially the same, functionally. In other > words, I think we agree on what the expected behavior should be : -) > We just have to agree on what presentation would make the most sense > for the user. This sounds good to me. We still need to finalize the interface, 'mode' or 'auto'. Personally, I prefer 'auto', because it's simpler. >> > what should a subsequent `cat auto node0 node1` output? >> > >> > `false 5 1` >> > or >> > `false 1 1` >> >> IMO, it should be >> >> `false 5 1` >> >> That is, we copy auto-generated weights to manual weights atomically and >> use it. >> >> > Then lets say we do >> > echo 7 > node0 >> >> Now, `cat auto node0 node1` outputs, >> >> `false 7 1` >> >> That is, we delete manual weights and use the auto-generated ones. >> >> > what should >> > echo true > auto >> > result in? >> > >> > `true 5 1` >> > or >> > `true 7 1` >> >> It should be >> >> `true 5 1` > > I see, so I think we actually agree on what the behavior for this is. > Then there is no real "hidden state", it's either just using the > default weights, or turning that off and being able to edit the > states. > >> > The current code makes sure that when you switch modes from auto >> > to manual, it inherits the current state - instead of there being >> > some hidden state that suddenly takes precedence. >> >> I think that we can do that with two weight arrays. >> >> > So I prefer to just have one IW array and no hidden state. >> >> Then, when we switch from manual to auto mode, where to find >> auto-generated weights? Re-calculate them? > > Even in manual mode, incoming bandwidth data is continuously stored. > This way, when a user does decide to switch back to auto mode later, > the system doesn't have to retrieve the bandwidth data all over again. > As for the auto-generated weights, they are re-calculated based solely > on the bandwidth data available. (I will note that re-calculating > the weights are very quick, see reduce_interleave_weights) > > Based on your description of the expected behavior, everything you > listed out is actually what currently happens in the one-layer system. > Switching from auto --> manual inherits the auto-generated weights, and > switching from manual --> auto wipes all previous user-stored data. > > At this point, I think that I am happy with either option. I wrote and > re-wrote this a bunch of times, and came to the conclusion that now > that we agree on the behavior of the interface, I have no strong > opinion on whether we have a "hidden" default layer or a phantom > default layer that is just generated every time a user needs it : -) > > Please let me know if I missed anything as well! Thank you all for > your continued feedback and interest! Have a great day, I see. You cache the nodes bandwidth instead of default weights. That works. I am fine with either way too. --- Best Regards, Huang, Ying
