That first branch testing pkg against __max_logical_packages is wrong, because if the first pkg id is larger, then the find_first_zero will find us logical package id 0. However, if the second pkg id is indeed 0, we'll again claim it without testing if it was already taken. Also, it fails to print the mapping. Cc: Ingo Molnar Cc: Borislav Petkov Cc: Thomas Gleixner Cc: Andreas Herrmann Reported-by: Xiong Zhou Fixes: 1f12e32f4cd5 ("x86/topology: Create logical package id") Signed-off-by: Peter Zijlstra (Intel) Link: http://lkml.kernel.org/r/20160317095220.GO6344@twins.programming.kicks-ass.net --- arch/x86/kernel/cpu/amd.c | 8 ++++---- arch/x86/kernel/smpboot.c | 11 ++++++----- 2 files changed, 10 insertions(+), 9 deletions(-) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -274,11 +274,6 @@ int topology_update_package_map(unsigned if (test_and_set_bit(pkg, physical_package_map)) goto found; - if (pkg < __max_logical_packages) { - set_bit(pkg, logical_package_map); - physical_to_logical_pkg[pkg] = pkg; - goto found; - } new = find_first_zero_bit(logical_package_map, __max_logical_packages); if (new >= __max_logical_packages) { physical_to_logical_pkg[pkg] = -1;