I have ran another experiment for nearly two days, and I have to say that the main Orion process seems to be doing much better, but there are several subprocesses that didn't exist when I first opened this bug report that contain a large amount of memory held, so not sure if the "fix" for the main Orion process was by splitting some things out to subprocesses or what. Anyways, on to the results!
I performed this test with only one extension enabled, the Bitwarden extension.
Startup time: Friday, August 05, 2022 at 19:52
Tabs currently open:
Processes running: 9
1 x "Orion" (92.3 MB)
2 x "Orion Web Content" (174.4, 68.6 MB)
1 x "Orion Web Content (Prewarmed)" (12.7 MB)
1 x "Orion Networking" (20.8 MB)
3 x "com.apple.audio.SandBoxHelper" (2.8, 2.8, 2.7 MB)
1 x "com..apple.WebKit.GPU.Orion" (9.7 MB)
Total memory usage: 386.8 MB
Shutdown time: Sunday, August 07, 2022 at 10:33
Tabs currently open:
Processes running: 20
1 x "Orion" (709.9 MB)
2 x "Orion Web Content" (1.15 GB, 753.5 MB)
15 x "Orion Web Content (Prewarmed)" (429.7, 409.0, 267.2, 187.1, 161.6, 151.7, 133.2, 126.1, 116.9, 103.9, 97.6, 94.3, 79.9, 50.2, 49.1 MB)
1 x "Orion Networking" (120.1 MB)
1 x "com.apple.WebKit.GPU.Orion" (92.7 MB)
Total memory usage: 5,283.7 MB
So as you can see, in less than two days time spent using Orion, we went from under half a gig to over 5 gigs of memory held by the application. Interestingly there are a ton of "Orion Web Content (Prewarmed)" processes staying around holding on to a decent amount of memory.
As to the browsing history that lead me to this state, I poked around in my Library under Orion and found a file history that was a sqlite DB. I used the sqlite DB viewer and exported the table history_items which shows the browsing history. I'm going to filter that down to the time window I recorded this data. That said, after a cursory review, there is a lot of incredibly sensitive information, so I will not post it publicly here, and I'm hesitant to even share it privately.
What more can we be doing to help debug this?