Date: Sat, 13 Mar 2004 14:37:37 +0100 From: a@jenisch.at To: freebsd-questions@freebsd.org Subject: SMP vs. Hyperthreading? Message-ID: <20040313133737.GA21068@athena.oekb.co.at>
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Hi, I've got a machine with a P4 that supports HTT (Hyperthreading) so I thought about setting up a SMP-kernel. Under 4.9 it seems to work (see excerpts from /var/log/messages below), whereas on the same exact hardware under 5.2.1 I don't see two virtual CPUs working. For a first check I've run "cpuburn" (i.e. burnP6). Under 4.9 with one "cpuburn" process active "top" etc. show a cpu-load of about 50% which for me means SMP/HTT is active. Under 5.2.1 it's a different story though: /var/log/messages shows that there are 2 CPUs but the message indicating the second CPU has been launched is missing ("/kernel: SMP: AP CPU #1 Launched!"). When I run a "cpuburn"-Test under 5.2.1 CPU load indicated by "top" shows 100% so I assume SMP/HTT is not active. So my primary question is - how do I get SMP running under 5.2.1 with a hyperthreading-capable P4?? Thanks much in advance for any clue, -ewald ------------------------------ < Cut here > ------------------------------ Excerpt from /var/log/messages - 4.9: Mar 12 15:00:30 mybox /kernel: CPU: Intel(R) Pentium(R) 4 CPU 2.60GHz (2593.68-MHz 686-class CPU) Mar 12 15:00:30 mybox /kernel: Origin = "GenuineIntel" Id = 0xf29 Stepping = 9 Mar 12 15:00:30 mybox /kernel: Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLF LUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE> Mar 12 15:00:30 mybox /kernel: Hyperthreading: 2 logical CPUs Mar 12 15:00:30 mybox /kernel: real memory = 394264576 (385024K bytes) Mar 12 15:00:30 mybox /kernel: avail memory = 377823232 (368968K bytes) Mar 12 15:00:30 mybox /kernel: Changing APIC ID for IO APIC #0 from 1 to 2 in MP table Mar 12 15:00:30 mybox /kernel: APIC_IO: MP table broken: 8259->APIC entry missing! Mar 12 15:00:30 mybox /kernel: Changing APIC ID for IO APIC #0 from 0 to 2 on chip Mar 12 15:00:30 mybox /kernel: Programming 24 pins in IOAPIC #0 Mar 12 15:00:30 mybox /kernel: FreeBSD/SMP: Multiprocessor motherboard: 2 CPUs Mar 12 15:00:30 mybox /kernel: cpu0 (BSP): apic id: 0, version: 0x00050014, at 0xfee00000 Mar 12 15:00:30 mybox /kernel: cpu1 (AP): apic id: 1, version: 0x00050014, at 0xfee00000 ... Mar 12 15:00:30 mybox /kernel: SMP: AP CPU #1 Launched! ------------------------------ < Cut here > ------------------------------ Excerpt from /var/log/messages - 5.2.1: Mar 13 08:49:22 mybox kernel: CPU: Intel(R) Pentium(R) 4 CPU 2.60GHz (2593.68-MHz 686-class CPU) Mar 13 08:49:22 mybox kernel: Origin = "GenuineIntel" Id = 0xf29 Stepping = 9 Mar 13 08:49:22 mybox kernel: Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,M CA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE> Mar 13 08:49:22 mybox kernel: Hyperthreading: 2 logical CPUs Mar 13 08:49:22 mybox kernel: real memory = 394264576 (376 MB) Mar 13 08:49:22 mybox kernel: avail memory = 376074240 (358 MB) Mar 13 08:49:22 mybox kernel: MPTable: <COMPAQ > Mar 13 08:49:22 mybox kernel: ioapic0: Changing APIC ID to 1 Mar 13 08:49:22 mybox kernel: ioapic0: Assuming intbase of 0 Mar 13 08:49:22 mybox kernel: ioapic0 <Version 2.0> irqs 0-23 on motherboard Mar 13 08:49:22 mybox kernel: Pentium Pro MTRR support enabled Mar 13 08:49:22 mybox kernel: cpu0 on motherboard Mar 13 08:49:22 mybox kernel: npx0: [FAST]
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