Hello! Just cvsup-ed and upgraded to 6.2-STABLE. The box has hyperthreading processor: # more /var/run/dmesg.boot |grep -i cpu CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz (3000.37-MHz 686-class CPU) Logical CPUs per core: 2 FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs cpu0 (BSP): APIC ID: 0 cpu1 (AP): APIC ID: 1 cpu0: <ACPI CPU> on acpi0 cpu1: <ACPI CPU> on acpi0 SMP: AP CPU #1 Launched! and also sysctl shows that it is: kern.threads.virtual_cpu: 2 kern.smp.cpus: 2 hw.ncpu: 2 machdep.hlt_cpus: 2 machdep.logical_cpus_mask: 2 dev.cpu.0.%desc: ACPI CPU dev.cpu.0.%driver: cpu dev.cpu.0.%location: handle=\_PR_.CPU0 dev.cpu.0.%pnpinfo: _HID=none _UID=0 dev.cpu.0.%parent: acpi0 dev.cpu.0.cx_supported: C1/0 dev.cpu.0.cx_lowest: C1 dev.cpu.0.cx_usage: 100.00% dev.cpu.1.%desc: ACPI CPU dev.cpu.1.%driver: cpu dev.cpu.1.%location: handle=\_PR_.CPU1 dev.cpu.1.%pnpinfo: _HID=none _UID=0 dev.cpu.1.%parent: acpi0 dev.cpu.1.cx_supported: C1/0 dev.cpu.1.cx_lowest: C1 dev.cpu.1.cx_usage: 0% When I run several concurrent processes I do not see that the CPU1 is used at all! The 'top' shows this, and the sysctl shows this: dev.cpu.0.cx_usage: 100.00% dev.cpu.1.cx_usage: 0% last pid: 732; load averages: 7.94, 5.19, 2.52 up 0+00:29:42 23:39:43 38 processes: 9 running, 29 sleeping CPU states: 99.3% user, 0.0% nice, 0.7% system, 0.0% interrupt, 0.0% idle Mem: 34M Active, 15M Inact, 40M Wired, 34M Buf, 145M Free Swap: 469M Total, 469M Free PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU COMMAND 691 root 1 112 0 2628K 1984K RUN 0 0:45 12.01% perl5.8.8 693 root 1 112 0 2628K 1984K RUN 0 0:41 11.96% perl5.8.8 696 root 1 112 0 2628K 1984K RUN 0 0:40 11.96% perl5.8.8 698 root 1 112 0 2628K 1984K RUN 0 0:37 11.96% perl5.8.8 690 root 1 112 0 2628K 1984K RUN 0 0:44 11.91% perl5.8.8 694 root 1 112 0 2628K 1984K RUN 0 0:42 11.91% perl5.8.8 697 root 1 112 0 2628K 1984K RUN 0 0:38 11.91% perl5.8.8 723 root 1 112 0 2628K 1984K RUN 0 0:22 11.09% perl5.8.8 What it can be???? -- Oles mailto:don_oles@able.com.ua
On Jan 25, 2007, at 3:48 PM, Oles Hnatkevych wrote:> Hello! > > Just cvsup-ed and upgraded to 6.2-STABLE. > > The box has hyperthreading processor: >check value of machdep.hyperthreading_allowed sysctl.
Oles Hnatkevych wrote:> Hello! > > Just cvsup-ed and upgraded to 6.2-STABLE. > > The box has hyperthreading processor: > > # more /var/run/dmesg.boot |grep -i cpu > CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz (3000.37-MHz 686-class CPU) > Logical CPUs per core: 2 > FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs > cpu0 (BSP): APIC ID: 0 > cpu1 (AP): APIC ID: 1 > cpu0: <ACPI CPU> on acpi0 > cpu1: <ACPI CPU> on acpi0 > SMP: AP CPU #1 Launched![...]> What it can be????This is done intentionally on all -STABLE branches, see http://security.freebsd.org/advisories/FreeBSD-SA-05:09.htt.asc for details. Note that it is possible to re-enable htt if you know what you are doing, by setting machdep.hyperthreading_allowed. Please note that enabling hyperthreading does hurt performance for many cases, so you will want to evaluate if you really want it, or to disable it from BIOS. Cheers, -- Xin LI <delphij@delphij.net> http://www.delphij.net/ FreeBSD - The Power to Serve! -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 249 bytes Desc: OpenPGP digital signature Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20070125/b27456fc/signature.pgp
Hello! I believe that the kernel boot messages should explicitly tell that hyperthreading is disabled by default, so the guys like me won't be confused. ;-) OH> Hello! OH> Just cvsup-ed and upgraded to 6.2-STABLE. OH> The box has hyperthreading processor: OH> # more /var/run/dmesg.boot |grep -i cpu OH> CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz (3000.37-MHz 686-class CPU) OH> Logical CPUs per core: 2 OH> FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs OH> cpu0 (BSP): APIC ID: 0 OH> cpu1 (AP): APIC ID: 1 OH> cpu0: <ACPI CPU> on acpi0 OH> cpu1: <ACPI CPU> on acpi0 OH> SMP: AP CPU #1 Launched! -- freebsd-stable mailto:freebsd-stable@freebsd.org