From: Thomas Gleixner tglx@linutronix.de
The new AMD/HYGON topology parser evaluates the SMT information in CPUID leaf 0x8000001e unconditionally while the original code restricted it to CPUs with family 0x17 and greater.
This breaks family 0x15 CPUs which advertise that leaf and have a non-zero value in the SMT section. The machine boots, but the scheduler complains loudly about the mismatch of the core IDs:
WARNING: CPU: 1 PID: 0 at kernel/sched/core.c:6482 sched_cpu_starting+0x183/0x250 WARNING: CPU: 0 PID: 1 at kernel/sched/topology.c:2408 build_sched_domains+0x76b/0x12b0
Add the condition back to cure it.
[ bp: Make it actually build because grandpa is not concerned with trivial stuff. :-P ]
Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser") Closes: https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/issues/56 Reported-by: Tim Teichmann teichmanntim@outlook.de Reported-by: Christian Heusel christian@heusel.eu Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Tested-by: Tim Teichmann teichmanntim@outlook.de Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/7skhx6mwe4hxiul64v6azhlxnokheorksqsdbp7qw6g2jduf6c... (cherry picked from commit 34bf6bae3286a58762711cfbce2cf74ecd42e1b5) Signed-off-by: Christian Heusel christian@heusel.eu --- arch/x86/kernel/cpu/topology_amd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/topology_amd.c b/arch/x86/kernel/cpu/topology_amd.c index ce2d507c3b07..5ee6373d4d92 100644 --- a/arch/x86/kernel/cpu/topology_amd.c +++ b/arch/x86/kernel/cpu/topology_amd.c @@ -84,9 +84,9 @@ static bool parse_8000_001e(struct topo_scan *tscan, bool has_0xb)
/* * If leaf 0xb is available, then the domain shifts are set - * already and nothing to do here. + * already and nothing to do here. Only valid for family >= 0x17. */ - if (!has_0xb) { + if (!has_0xb && tscan->c->x86 >= 0x17) { /* * Leaf 0x80000008 set the CORE domain shift already. * Update the SMT domain, but do not propagate it. -- 2.45.2