I tested the implementation of spinlocks in 2.1.89 and booted an SMP kernel
on my single CPU machine (FIC PA-2010, VIA Apollo VP, 1xIBM 6x86-P166+ at
133 MHz) and the bogomips (= frequency in MHz on this CPU) dropped from 133
to 33. Not only the bogusmips value drops but also the system performance.
With CPU intensive code, I see exactly the same thing: 1/4 of the
performance, I have with a UP kernel.
Anybody got any idea. May the APIC code touch chipset or processor ports?
Here's are some boot messages:
klogd 1.3-0, log source = /proc/kmsg started.
<4>Linux version 2.1.89 (root@kg1) (gcc version egcs-2.91.14 980315 (gcc-2.8.0 release)) #82 Tue Mar 17 20:59:22 CET 1998
<4>INIT IRQ
<4>Console: 16 point font, 400 scans
<4>Console: colour VGA+ 80x25, 1 virtual console (max 63)
<4>PCI: BIOS32 Service Directory structure at 0xc00fb000
<4>PCI: BIOS32 Service Directory entry at 0xfb400
<4>PCI: PCI BIOS revision 2.10 entry at 0xfb430
<4>Probing PCI hardware.
<4>PCI->APIC IRQ transform: (B0,I0,P-1) -> -1
<4>PCI->APIC IRQ transform: (B0,I7,P-1) -> -1
<4>PCI->APIC IRQ transform: (B0,I7,P-1) -> -1
<4>PCI->APIC IRQ transform: (B0,I8,P0) -> -1
<4>PCI->APIC IRQ transform: (B0,I9,P0) -> -1
<4>PCI->APIC IRQ transform: (B0,I11,P0) -> -1
<4>Calibrating delay loop... 33.13 BogoMIPS
<4>Memory: 63260k/65536k available (780k kernel code, 400k reserved, 1044k data, 52k init)
<4>Checking if this processor honours the WP bit even in supervisor mode... Ok.
<6>Swansea University Computer Society NET3.039 for Linux 2.1
<5>IEEE 802.2 LLC for Linux 2.1 (c) 1996 Tim Alpaerts
<6>Swansea University Computer Society TCP/IP for NET3.037
<6>IP Protocols: ICMP, UDP, TCP
<5>VFS: Diskquotas version dquot_5.6.0 initialized
<6>Checking 386/387 coupling... Ok, fpu using exception 16 error reporting.
<6>Checking 'hlt' instruction... Ok.
<4>POSIX conformance testing by UNIFIX
<4>CPU0: Cyrix 6x86 2x Core/Bus Clock stepping 17
<5>SMP motherboard not detected. Using dummy APIC emulation.
<4>Starting kswapd v 1.5
-- Kurt Garloff, Dortmund <K.Garloff@ping.de> PGP key on http://student.physik.uni-dortmund.de/homepages/garloff- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu