From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262346AbULCQ3V (ORCPT ); Fri, 3 Dec 2004 11:29:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262349AbULCQ3V (ORCPT ); Fri, 3 Dec 2004 11:29:21 -0500 Received: from www1.cdi.cz ([194.213.194.49]:732 "EHLO www1.cdi.cz") by vger.kernel.org with ESMTP id S262346AbULCQ3J (ORCPT ); Fri, 3 Dec 2004 11:29:09 -0500 Date: Fri, 3 Dec 2004 17:28:47 +0100 (CET) From: devik X-X-Sender: To: Subject: Re: sched isolcpus=1 related OOPS in 2.6.9 In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > only CPU#0 use (I want to use affinity to select CPU#1). > The OOPS triggers every time when I use isolcpus. > > I traced the problem down into sched.c:1928 (find_busiest_group) > where group->cpu_power was zero (thus division by zero occured). > In call trace it goes swapper->schedule()->........->find_busiest_group. > Important registers there: eax=ecx=edx=0, ebx!=0. Well, I have more info. I setup bochs smp emulator and hacked printk to output into e9 port which is then directed to a file. Also I turned sched_domains debugging. From the result (below) is clear that there is bug in isolated domains setup. devik <6>BIOS-provided physical RAM map: BIOS-e820: 0000000000000000 - 000000000009fc00 (usable) BIOS-e820: 0000000000100000 - 0000000002000000 (usable) <5>32MB LOWMEM available. <6>found SMP MP-table at 000fd0f0 <7>On node 0 totalpages: 8192 <7> DMA zone: 4096 pages, LIFO batch:1 <7> Normal zone: 4096 pages, LIFO batch:1 <7> HighMem zone: 0 pages, LIFO batch:1 <6>DMI not present. <3>ACPI: Unable to locate RSDP <6>Intel MultiProcessor Specification v1.4 <6> Virtual Wire compatibility mode. <6>OEM ID: BOCHSCPU Product ID: 0.1 APIC at: 0xFEE00000 Processor #0 6:0 APIC version 17 Processor #1 6:0 APIC version 17 <6>I/O APIC #2 Version 17 at 0xFEC00000. Enabling APIC mode: Flat. Using 1 I/O APICs <6>Processors: 2 Built 1 zonelists Kernel command line: BOOT_IMAGE=linux ro root=301 apic=debug noapic isolcpus=1 mapped APIC to ffffd000 (fee00000) mapped IOAPIC to ffffc000 (fec00000) <6>Initializing CPU#0 CPU 0 irqstacks, hard=c035b000 soft=c0359000 PID hash table entries: 256 (order: 8, 4096 bytes) Detected 2.001 MHz processor. <6>Using tsc for high-res timesource Console: colour VGA+ 80x50 Dentry cache hash table entries: 8192 (order: 3, 32768 bytes) Inode-cache hash table entries: 4096 (order: 2, 16384 bytes) <6>Memory: 29372k/32768k available (1511k kernel code, 2960k reserved, 698k data, 168k init, 0k highmem) Checking if this processor honours the WP bit even in supervisor mode... Ok. <7>Calibrating delay loop... 8.19 BogoMIPS (lpj=4096) Mount-cache hash table entries: 512 (order: 0, 4096 bytes) <7>CPU: After generic identify, caps: 0180a379 00000000 00000000 00000000 <7>CPU: After vendor identify, caps: 0180a379 00000000 00000000 00000000 <7>CPU: After all inits, caps: 0180a379 00000000 00000000 00000040 <6>Enabling fast FPU save and restore... done. <6>Checking 'hlt' instruction... OK. CPU0: Intel Pentium III (Coppermine) stepping 03 per-CPU timeslice cutoff: 81.50 usecs. task migration cache decay timeout: 1 msecs. Getting VERSION: 170011 Getting VERSION: 170011 Getting ID: 0 Getting LVT0: 0 Getting LVT1: 0 enabled ExtINT on CPU#0 Booting processor 1/1 eip 2000 CPU 1 irqstacks, hard=c035c000 soft=c035a000 <6>Initializing CPU#1 masked ExtINT on CPU#1 <7>Calibrating delay loop... 8.19 BogoMIPS (lpj=4096) <7>CPU: After generic identify, caps: 0180a379 00000000 00000000 00000000 <7>CPU: After vendor identify, caps: 0180a379 00000000 00000000 00000000 <7>CPU: After all inits, caps: 0180a379 00000000 00000000 00000040 CPU1: Intel Pentium III (Coppermine) stepping 03 <6>Total of 2 processors activated (16.38 BogoMIPS). Using local APIC timer interrupts. calibrating APIC timer ... ..... CPU clock speed is 1.0999 MHz. ..... host bus clock speed is 1.0999 MHz. <6>checking TSC synchronization across 2 CPUs: <6>CPU#0 had 0 usecs TSC skew, fixed it up. <6>CPU#1 had 0 usecs TSC skew, fixed it up. Brought up 2 CPUs <6>Setting up cpu 1 isolated. <7>CPU0: online <7> domain 0: span 3 <7> groups: 1 2 <7>CPU1: online <7> domain 0: span 2 <7>ERROR domain->cpu_power not set <7> groups: 2 <1>divide error: 0000 [#1] SMP Modules linked in: CPU: 0 EIP: 0060:[] Not tainted VLI EFLAGS: 00010046 (2.6.9imq) EIP is at find_busiest_group+0x2b3/0x310 eax: 00000000 ebx: c10b2e74 ecx: 00000000 edx: 00000000 esi: c0360ee8 edi: c0351000 ebp: c10b2e84 esp: c10b2e38 ds: 007b es: 007b ss: 0068 Process swapper (pid: 1, threadinfo=c10b2000 task=c10b15a0) Stack: c10b2e74 00000002 00000002 00004441 08bca3a6 c0351000 00000000 00000001 00000080 00000080 00000080 00000000 00000000 c0360edc 00000000 00000002 00000040 c1044940 00000001 c10b2eb8 c0117125 c1044940 00000000 c10b2ea8 Call Trace: [] show_stack+0x7f/0xa0 [] show_registers+0x15e/0x1c0 [] die+0xf4/0x180 [] do_divide_error+0x10b/0x130 [] error_code+0x2d/0x38 [] load_balance+0x35/0x1a0 [] rebalance_tick+0xba/0xd0 [] scheduler_tick+0x122/0x480 [] update_process_times+0x45/0x50 [] smp_apic_timer_interrupt+0xf8/0x100 [] apic_timer_interrupt+0x1a/0x20 [] unpack_to_rootfs+0x17a/0x200 [] populate_rootfs+0x2b/0x120 [] init+0x8a/0x1e0 [] kernel_thread_helper+0x5/0x10 Code: 00 0f 4d c2 83 f8 01 89 c1 7e ad 8b 4d d0 85 c9 0f 84 fe fd ff ff 8b 45 e0 01 45 dc 89 c2 8b 4e 08 01 4d d4 c1 e2 07 89 d0 31 d2 f1 8b 55 cc 85 d2 89 45 e0 75 1c 8b 45 e4 39 45 e0 76 09 89