An update on the WebContent crashing/beachballing Safari 18.4 in 15.4. Looks like a segfault to me from a brief look at the logs. Disabled all extensions, it still persisted. Develop/Empty caches for all profiles seems to have cleared it, though. No longer beachballing on JS‑heavy websites after that, at least for now. Weird.
Pludgapalooza: MacOS 15.4, iOS 18.4, iPadOS 18.4, etc, etc.
- Thread starter cateye
- Start date
Hmm, sounds like caches of JITted script may be the culprit. Real-world upgrade scenarios are difficult to automate and cover but this shouldn't have slipped by Apple QA. Sigh.
I've been seeing frequent and dramatic UI stutters in Safari on the iPad. Scrolling dropping from 120fps to <10 – it's bad. I'll give this a try, thank you.
That indeed sounds likely. Delving into the crash report a bit deeper, I saw it had "JS VM Gigacage (reserved)" of over 60GB (WTF?), and it seems like JIT cache and JavaScriptCore's scavenger thread related. Could be that the WebKit in 15.3.x was a bit more fault-tolerant of corrupted cache (I did indeed notice some JS-heavy sites having hiccups lately on 15.3.x, whereas the system in 15.4 just SEGFAULTed outright on corrupt data (which shouldn't be there in the first place, but well). Still, it was a
EXC_BAD_ACCESS (SIGSEGV) & KERN_INVALID_ADDRESS, which shouldn't have slipped by their QA indeed. That sounds a bit worse than just JIT cache bonking out.
Try that, it might help, if your problems are related. Or perhaps no, who knows ;-)
Unfrotunately I don't see any easy option of deleting just the all the caches in mobile safari's developer menu, just the usual clear website data and history. Maybe it's the same (clearing the caches through developer menu on desktop safari doesn't erase history or cookies).
It gets weirder: each one of the stations actually has four different playlists you can choose from, but you can’t select which one you want from the button itself or change it on a whim. Instead, you have to go into edit mode and select the specific playlist from the control’s settings, then save the changes. I never, ever would have discovered this on my own: https://www.macrumors.com/how-to/ios-18-4-access-hidden-ambient-music-playlists.
Who came up with this UI?! Why can’t you just long-press on the button to choose which playlist you want?
I had one macOS update like that a few years back. Out of nowhere Safari was horribly borked. I ended up having to restore from backup to get it working.
As for 18.4/15.4/11.4, my iPad, iPhone, MacBook and Watch all seem fine after the update.
My AirPods 4 also got their new update but no problems there either.
One interesting thing: I'm not located in the US, but for some reason I've received Apple Intelligence at separate times:
- The MacBook got it with 15.2
- The iPad got it with 18.4
- My iPhone 15 isn't eligible (only 6GB RAM)
As far as I know they both have the same region settings (primary language English, location NL), and for both of them I have Siri set to English UK. Yet they became entitled to Apple Intelligence at completely different times.
