Date: Sun, 04 Jan 2026 02:28:49 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 292167] occasional SMP APs not starting on ppc64 guests Message-ID: <bug-292167-227-DmXL1ciVed@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-292167-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=292167 --- Comment #4 from commit-hook@FreeBSD.org --- A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=8df2e542146801fd01675e56724eaa567d04c209 commit 8df2e542146801fd01675e56724eaa567d04c209 Author: Adrian Chadd <adrian@FreeBSD.org> AuthorDate: 2026-01-03 22:52:14 +0000 Commit: Adrian Chadd <adrian@FreeBSD.org> 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.home | help
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