https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=292167
--- Comment #4 from [email protected] --- A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=8df2e542146801fd01675e56724eaa567d04c209 commit 8df2e542146801fd01675e56724eaa567d04c209 Author: Adrian Chadd <[email protected]> AuthorDate: 2026-01-03 22:52:14 +0000 Commit: Adrian Chadd <[email protected]> CommitDate: 2026-01-04 02:27:48 +0000 powerpc: put the isync inside the TD_LOCK() checking loop Fix a narrow window where the lock is unlocked but the checking CPU hasn't flushed things appropriately. Inside this window the CPU inside cpu_switch() will loop forever thinking the destination thread is still blocked/locked even though it is not. This manifests as the system hanging after starting all APs. I've seen this reliably trigger in qemu-system-ppc64 running power9 pseries guests; the more CPUs the more likely it triggers at boot. PR: kern/292167 Differential Revision: https://reviews.freebsd.org/D54478 Reviewed by: jhibbits MFC after: 1 week Relnotes: yes sys/powerpc/powerpc/swtch32.S | 2 +- sys/powerpc/powerpc/swtch64.S | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) -- You are receiving this mail because: You are the assignee for the bug.
