(In reply to CodingEagle02 from comment #545) > Hey out of curiosity, since I can't seem to find a clear answer, what > exactly does idle=halt do?
idle=halt disables ACPI MWAIT completely, and issues HALT instead of different C-states for idle. Without idle=halt, both my machines are issuing errors upon boot ([Firmware Bug]: ACPI MWAIT C-state 0x0 not supported by HW (0x0)), which disappears when idle=halt is set. Borislav Petkov has a suspicion about what happens (comment 531): "In order to understand what's *really* going on in the cstate detection code one would need to instrument at least acpi_processor_get_power_info_cst() and acpi_processor_ffh_cstate_probe() to figure out what exactly does the kernel parse from those CST objects and what it uses to try to enter idle. And do all that instrumentation on an affected system. My current suspicion is is that it tries to enter idle with misconfigured states and under certain conditions, it misses the wakeup, leading to the stall." I have successfully used idle=halt for over a month now, without a single lockup! -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1690085 Title: Ryzen 1800X freeze - rcu_sched detected stalls on CPUs/tasks To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1690085/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
