Scanning results take a long time to return back to users

[ellie-idb]

Is this the fault of the scan cache?
There are DEFINITELY some good ways to optimize this and make it more efficient...
but why aren't they working?

[itsmattkc]

Not sure if this is relevant, but something I noticed was that it seems to request a scan of the same channels over and over, as if the OS doesn't retrieve them correctly the first few times:

default	03:05:45.976315+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 1 to scan
default	03:05:45.976315+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 2 to scan
default	03:05:45.976316+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 3 to scan
default	03:05:45.976317+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 4 to scan
default	03:05:45.976319+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 5 to scan
default	03:05:45.976320+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 6 to scan
default	03:05:47.536953+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 1 to scan
default	03:05:47.536957+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 2 to scan
default	03:05:47.536959+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 3 to scan
default	03:05:47.536962+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 4 to scan
default	03:05:47.536966+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 5 to scan
default	03:05:47.536967+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 6 to scan
default	03:05:49.095835+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 1 to scan
default	03:05:49.095838+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 2 to scan
default	03:05:49.095839+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 3 to scan
default	03:05:49.095841+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 4 to scan
default	03:05:49.095844+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 5 to scan
default	03:05:49.095845+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 6 to scan
default	03:05:50.654591+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 1 to scan
default	03:05:50.654596+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 2 to scan
default	03:05:50.654599+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 3 to scan
default	03:05:50.654602+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 4 to scan
default	03:05:50.654604+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 5 to scan
default	03:05:50.654608+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 6 to scan
default	03:05:52.208908+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 1 to scan
default	03:05:52.208909+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 2 to scan
default	03:05:52.208911+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 3 to scan
default	03:05:52.208914+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 4 to scan
default	03:05:52.208915+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 5 to scan
default	03:05:52.208918+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 6 to scan
default	03:05:53.566735+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 7 to scan
default	03:05:53.566737+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 8 to scan
default	03:05:53.566740+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 9 to scan
default	03:05:53.566741+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 10 to scan
default	03:05:53.566742+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 11 to scan
default	03:05:53.566745+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 12 to scan
default	03:05:55.125679+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 7 to scan
default	03:05:55.125680+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 8 to scan
default	03:05:55.125683+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 9 to scan
default	03:05:55.125684+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 10 to scan
default	03:05:55.125686+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 11 to scan
default	03:05:55.125689+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 12 to scan
default	03:05:56.684612+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 7 to scan
default	03:05:56.684616+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 8 to scan
default	03:05:56.684617+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 9 to scan
default	03:05:56.684619+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 10 to scan
default	03:05:56.684622+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 11 to scan
default	03:05:56.684623+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 12 to scan
default	03:05:58.239757+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 7 to scan
default	03:05:58.239758+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 8 to scan
default	03:05:58.239762+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 9 to scan
default	03:05:58.239764+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 10 to scan
default	03:05:58.239767+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 11 to scan
default	03:05:58.239769+1000	kernel	AppleIntelWifiAdapter DEBUG: adding chan 12 to scan

(filtered console output, there are a lot of lines that have been omitted between each set of 6)

[ellie-idb]

I’ve tried to take a stab at this again with more scan cache optimizations, but we have a problem where wireless networks tend to disappear..