1474017 - Determine if RCWN (Race Cache with Network) optimization should be turned on for mobile (wifi only)

Status: RESOLVED DUPLICATE of bug 1377570

(Firefox for Android Graveyard :: General, enhancement)

Description

[Jason Duell]

RCWN (bug RCWN) was a significant win on desktop--we saw desktop hard drives perform poorly enough often enough that racing the network resulted in some real wins (10ms faster channel loads on average, with wins of multiple seconds for really slow cases).

We should see if this should get enabled on mobile as well.  The HTTP cache is smaller on mobile, so there's less overall win there.  But storage latencies on mobile can also be awful, so that points toward more win.

Note: RCWN doesn't use any additional disk storage, and has minimal RAM/CPU overhead, but it does use up network bandwidth speculatively, so RCWN should probably only be enabled if the phone is on wifi.

Michal is the necko point person for this work, but we should do a kickoff with some mobile folks for sanity checking, and I also suspect we may need help with performance metrics (we used telemetry for this last time, and that's probably the way to go forward here too?)