On Fri, Apr 21, 2023 at 03:53:30PM -0700, Douglas Anderson wrote: > From: Colin Cross <ccr...@android.com> > > Implement a hardlockup detector that can be enabled on SMP systems > that don't have an arch provided one or one implemented atop perf by > using interrupts on other cpus. Each cpu will use its softlockup > hrtimer to check that the next cpu is processing hrtimer interrupts by > verifying that a counter is increasing. > > NOTE: unlike the other hard lockup detectors, the buddy one can't > easily provide a backtrace on the CPU that locked up. It relies on > some other mechanism in the system to get information about the locked > up CPUs. This could be support for NMI backtraces like [1], it could > be a mechanism for printing the PC of locked CPUs like [2], or it > could be something else. > > This style of hardlockup detector originated in some downstream > Android trees and has been rebased on / carried in ChromeOS trees for > quite a long time for use on arm and arm64 boards. Historically on > these boards we've leveraged mechanism [2] to get information about > hung CPUs, but we could move to [1].
On the Arm platforms is this code able to leverage the existing infrastructure to extract status from stuck CPUs: https://docs.kernel.org/trace/coresight/coresight-cpu-debug.html Daniel. _______________________________________________ Kgdb-bugreport mailing list Kgdb-bugreport@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
