Description of problem: Using RHELAS4 with 2.6.9-5 kernel and saw that 4 cpu's were being seen in /proc/cpuinfo aswell as dmesg but only 2 are physically present. Upgraded kernel to 2.6.9-22.0.1 and the problem still exist. No preformance or usability issues have resulted thus far, but we have not really stressed the server. We are using HP DL380, which is only capable of 2 CPU's and 2 CPU's are installed only. Version-Release number of selected component (if applicable): kernel-smp-2.6.9-22.0.1.EL How reproducible: Steps to Reproduce: 1.Install RHEL4AS on HP DL380 with 2 cpu's 2.Observe dmesg and /proc/cpuinfo for number of processors Actual results: 4 CPU's are seen by the operating system Expected results: 2 CPU's should be seen as 2 only are installed. Additional info: excerpt from dmesg: Initializing CPU#0 CPU 0 irqstacks, hard=c03e7000 soft=c03c7000 PID hash table entries: 4096 (order: 12, 65536 bytes) Detected 3201.622 MHz processor. Using tsc for high-res timesource Console: colour VGA+ 80x25 Dentry cache hash table entries: 131072 (order: 7, 524288 bytes) Inode-cache hash table entries: 65536 (order: 6, 262144 bytes) Memory: 4084732k/4653052k available (1863k kernel code, 43036k reserved, 753k data, 176k init, 3211208k highmem) Calibrating delay loop... 6307.84 BogoMIPS (lpj=3153920) Security Scaffold v1.0.0 initialized SELinux: Initializing. SELinux: Starting in permissive mode There is already a security framework initialized, register_security failed. selinux_register_security: Registering secondary module capability Capability LSM initialized as secondary Mount-cache hash table entries: 512 (order: 0, 4096 bytes) CPU: After generic identify, caps: bfebfbff 20000000 00000000 00000000 CPU: After vendor identify, caps: bfebfbff 20000000 00000000 00000000 monitor/mwait feature present. using mwait in idle threads. CPU: Trace cache: 12K uops, L1 D cache: 16K CPU: L2 cache: 1024K CPU0: Initial APIC ID: 0, Physical Processor ID: 0 CPU: After all inits, caps: bfebf3ff 20000000 00000000 00000080 Intel machine check architecture supported. Intel machine check reporting enabled on CPU#0. CPU0: Intel P4/Xeon Extended MCE MSRs (24) available CPU0: Thermal monitoring enabled Enabling fast FPU save and restore... done. Enabling unmasked SIMD FPU exception support... done. Checking 'hlt' instruction... OK. CPU0: Intel(R) Xeon(TM) CPU 3.20GHz stepping 01 per-CPU timeslice cutoff: 2925.73 usecs. task migration cache decay timeout: 3 msecs. Booting processor 1/1 eip 3000 CPU 1 irqstacks, hard=c03e8000 soft=c03c8000 Initializing CPU#1 Calibrating delay loop... 6389.76 BogoMIPS (lpj=3194880) CPU: After generic identify, caps: bfebfbff 20000000 00000000 00000000 CPU: After vendor identify, caps: bfebfbff 20000000 00000000 00000000 monitor/mwait feature present. CPU: Trace cache: 12K uops, L1 D cache: 16K CPU: L2 cache: 1024K CPU1: Initial APIC ID: 1, Physical Processor ID: 0 CPU: After all inits, caps: bfebf3ff 20000000 00000000 00000080 Intel machine check architecture supported. Intel machine check reporting enabled on CPU#1. CPU1: Intel P4/Xeon Extended MCE MSRs (24) available CPU1: Thermal monitoring enabled CPU1: Intel(R) Xeon(TM) CPU 3.20GHz stepping 01 Booting processor 2/6 eip 3000 CPU 2 irqstacks, hard=c03e9000 soft=c03c9000 Initializing CPU#2 Calibrating delay loop... 6389.76 BogoMIPS (lpj=3194880) CPU: After generic identify, caps: bfebfbff 20000000 00000000 00000000 CPU: After vendor identify, caps: bfebfbff 20000000 00000000 00000000 monitor/mwait feature present. CPU: Trace cache: 12K uops, L1 D cache: 16K CPU: L2 cache: 1024K CPU2: Initial APIC ID: 6, Physical Processor ID: 3 CPU: After all inits, caps: bfebf3ff 20000000 00000000 00000080 Intel machine check architecture supported. Intel machine check reporting enabled on CPU#2. CPU2: Intel P4/Xeon Extended MCE MSRs (24) available CPU2: Thermal monitoring enabled CPU2: Intel(R) Xeon(TM) CPU 3.20GHz stepping 01 Booting processor 3/7 eip 3000 CPU 3 irqstacks, hard=c03ea000 soft=c03ca000 Initializing CPU#3 Calibrating delay loop... 6389.76 BogoMIPS (lpj=3194880) CPU: After generic identify, caps: bfebfbff 20000000 00000000 00000000 CPU: After vendor identify, caps: bfebfbff 20000000 00000000 00000000 monitor/mwait feature present. CPU: Trace cache: 12K uops, L1 D cache: 16K CPU: L2 cache: 1024K CPU3: Initial APIC ID: 7, Physical Processor ID: 3 CPU: After all inits, caps: bfebf3ff 20000000 00000000 00000080 Intel machine check architecture supported. Intel machine check reporting enabled on CPU#3. CPU3: Intel P4/Xeon Extended MCE MSRs (24) available CPU3: Thermal monitoring enabled CPU3: Intel(R) Xeon(TM) CPU 3.20GHz stepping 01 Total of 4 processors activated (25477.12 BogoMIPS). ENABLING IO-APIC IRQs ..TIMER: vector=0x31 pin1=2 pin2=-1 checking TSC synchronization across 4 CPUs: passed. Brought up 4 CPUs /proc/cpuinfo contents: processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 4 model name : Intel(R) Xeon(TM) CPU 3.20GHz stepping : 1 cpu MHz : 3201.622 cache size : 1024 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm pni monitor ds_cpl cid xtpr bogomips : 6307.84 processor : 1 vendor_id : GenuineIntel cpu family : 15 model : 4 model name : Intel(R) Xeon(TM) CPU 3.20GHz stepping : 1 cpu MHz : 3201.622 cache size : 1024 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm pni monitor ds_cpl cid xtpr bogomips : 6389.76 processor : 2 vendor_id : GenuineIntel cpu family : 15 model : 4 model name : Intel(R) Xeon(TM) CPU 3.20GHz stepping : 1 cpu MHz : 3201.622 cache size : 1024 KB physical id : 3 siblings : 2 core id : 3 cpu cores : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm pni monitor ds_cpl cid xtpr bogomips : 6389.76 processor : 3 vendor_id : GenuineIntel cpu family : 15 model : 4 model name : Intel(R) Xeon(TM) CPU 3.20GHz stepping : 1 cpu MHz : 3201.622 cache size : 1024 KB physical id : 3 siblings : 2 core id : 3 cpu cores : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm pni monitor ds_cpl cid xtpr bogomips : 6389.76
NOTABUG. You have hyperthreading enabled on the processors, as you can see from the /proc/cpuinfo: look at "physical id" and "siblings". Turn off hyperthreading in the BIOS, or add "noht" to the kernel commandline.
indeed. the 'noht' command line is not available yet for RHEL4, but it should be implemented in U3. thanks.