I was getting random stalls on my iMac, with kernel_task taking up anywhere between 90-350% CPU without apparent cause ever since I upgraded to Big Sur 11.4. I may update this post (again) later if I have more details, but for now let’s start with the whats and hows: Context It annoys me to no end that I only noticed this was an issue due to my having tried to pick my network when doing Internet Recovery, which helped pin things down. * The year-on-year changes to Console.app (and the glacial slowness of the machine when stalling) made it very hard to spot patterns in logs.Īnd, of course, I have to get work done, so working through all the possible permutations was very slow. * The Wi-Fi icon was moved from the menu bar into Control Center (so status changes and error flashes are invisible). * I have a Gigabit Ethernet connection (so I only have Wi-Fi on for Continuity). But the reason I failed to notice this over the course of two weeks of trial and error troubleshooting is manifold: Summary: Every time I try to join that network, kernel_task immediately goes into a spin lock burning CPU cycles across all cores and stalling the machine, with variations of these two lines in the logs:ĪRPT: 2859.550473: wlc_phy_rx_iq_est_acphy: SPINWAIT ERROR : IQ measurement timed outĪRPT: 2859.550487: wl0: fatal error, reinitializing, total count of reinit's, Learned: I should have been even more systematic. Update, three weeks after the Big Sur 11.4 upgrade: Long story short, my current working theory is that 11.4 rendered my Wi-Fi card unable to associate to my 5GHz network (which is all based on Apple Airport Extremes), and that there is a macOS kernel bug that handles this situation very poorly.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |