SMP kernel fails to see second physical CPU with hyperthreading disabled Operating System: Red Hat 8.1 Beta 1 Details: Server (and Generation): ML370-G3 Rom version: P28 (8/16/2002) Processor info (class, speed & number of processors): 2 - 2.2GHz/512KB Xeons Memory (amount only): 512M What cards are installed and slot locations (also include firmware versions): Base configuration Broadcom NetXtreme boot rom v2.2.7 Drive locations: Internal bays 0 and 1 (9.1GB each) Boot controller: 3.02.01 Compaq Ultra 3 (Adaptec) Steps to reproduce: 1) Disable hyperthreading in RBSU 2) Install the OS (text-mode) 3) After installation, prompted to load either SMP or UP kernel by grub, choose SMP. 4) cat /proc/cpuinfo, reports only one CPU instead of 2. 5) init 6, enabled hyperthreading in RBSU and repeat step 3. 6) cat /proc/cpuinfo, reports four (4) CPUs now. uname -a output: Linux ml370g3 2.4.19-0.pp.15smp #1 SMP Thu Nov 14 13:57:02 EST 2002 i686 i686 i386 GNU/Linux Is the issue reproducible? Yes, repeatable on this system, as well as the 380-G3. Workaround: None found. ---------- Action by: Bryan.Leopard Issue Registered ---------- Action by: arjanv please try "acpi=off noht" as kernel option. If that fixes it your ACPI bios has a bug where it enumerates CPU's wrong. Status set to: Waiting on Client ---------- Action by: Bryan.Leopard That does work, in the sense that it allows the system to see both physical processors, but HT is obviously still an issue. Status set to: Waiting on Tech
Issue Tracker 11856
please retry this with the rawhide kernel; the HT cpu enumeration is significantly modified there.
closed due to inactivity in NEEDINFO