Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 30 Jul 2002 12:07:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 30 Jul 2002 12:07:56 -0400 Received: from mailrelay1.lanl.gov ([128.165.4.101]:5610 "EHLO mailrelay1.lanl.gov") by vger.kernel.org with ESMTP id ; Tue, 30 Jul 2002 12:07:54 -0400 Subject: 2.5.29, CPU#1 not working with CONFIG_SMP=y, 2.5.28 OK. From: Steven Cole To: linux-kernel@vger.kernel.org Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Evolution/1.0.2-5mdk Date: 30 Jul 2002 10:08:44 -0600 Message-Id: <1028045324.3148.32.camel@spc9.esa.lanl.gov> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2936 Lines: 91 On my dual p3 with an Intel STL2 motherboard, linux-2.5.29 does not see the second CPU properly. And yes, I double checked that I really had CONFIG_SMP=y for 2.5.29, rebuilding to make sure. 2.5.28 worked fine for SMP. Here are snippets from the dmesg output from 2.5.28 and 2.5.29: 2.5.28 dmesg snippet: Using local APIC timer interrupts. calibrating APIC timer ... ..... CPU clock speed is 999.0611 MHz. ..... host bus clock speed is 133.0281 MHz. cpu: 0, clocks: 133281, slice: 4038 CPU0 cpu: 1, clocks: 133281, slice: 4038 CPU1 checking TSC synchronization across CPUs: passed. migration_task 0 on cpu=0 migration_task 1 on cpu=1 Linux NET4.0 for Linux 2.4 2.5.29 dmesg snippet: Using local APIC timer interrupts. calibrating APIC timer ... ..... CPU clock speed is 999.0634 MHz. ..... host bus clock speed is 133.0284 MHz. cpu: 0, clocks: 133284, slice: 4038 CPU0 checking TSC synchronization across 2 CPUs: passed. Bringing up 3 CPUS done 4294967295 Linux NET4.0 for Linux 2.4 Earlier in the 2.5.29 dmesg output, the second CPU is initialized: Initializing CPU#1 masked ExtINT on CPU#1 ESR value before enabling vector: 00000000 ESR value after enabling vector: 00000000 Calibrating delay loop... 1994.75 BogoMIPS CPU: Before vendor init, caps: 0383fbff 00000000 00000000, vendor = 0 CPU: L1 I cache: 16K, L1 D cache: 16K CPU: L2 cache: 256K CPU: After vendor init, caps: 0383fbff 00000000 00000000 00000000 CPU: After generic, caps: 0383fbff 00000000 00000000 00000000 CPU: Common caps: 0383fbff 00000000 00000000 00000000 CPU1: Intel 00/08 stepping 06 Total of 2 processors activated (3969.02 BogoMIPS). The output of /proc/cpuinfo shows two cpus for 2.5.28 and only one for 2.5.29: [steven@spc5 steven]$ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 8 model name : 00/08 stepping : 6 cpu MHz : 1000.127 cache size : 256 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse bogomips : 1974.27 And indeed, the second cpu is not being used. I noticed this when running a benchmark for 2.5.29 which came out much lower, about half speed. I also tried Craig Kulesa's patches for rmap and slabLRU for 2.5.29 since the readme mentioned an SMP fix, but that kernel shows this same problem as vanilla 2.5.29. Steven  - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/