From patchwork Mon Dec 22 10:44:17 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chandru X-Patchwork-Id: 15217 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id A96D1DDE1A for ; Mon, 22 Dec 2008 21:44:43 +1100 (EST) X-Original-To: linuxppc-dev@ozlabs.org Delivered-To: linuxppc-dev@ozlabs.org Received: from e28smtp06.in.ibm.com (e28smtp06.in.ibm.com [59.145.155.6]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp06.in.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 155CCDDDDF for ; Mon, 22 Dec 2008 21:44:21 +1100 (EST) Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by e28smtp06.in.ibm.com (8.13.1/8.13.1) with ESMTP id mBMAiHQl017823 for ; Mon, 22 Dec 2008 16:14:17 +0530 Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id mBMAiJ5b3313694 for ; Mon, 22 Dec 2008 16:14:19 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.13.1/8.13.3) with ESMTP id mBMAiHa4016168 for ; Mon, 22 Dec 2008 21:44:17 +1100 Received: from guara.in.ibm.com (guara.in.ibm.com [9.124.35.51]) by d28av05.in.ibm.com (8.13.1/8.12.11) with ESMTP id mBMAiHSW016165 for ; Mon, 22 Dec 2008 21:44:17 +1100 From: Chandru Organization: ibm To: linuxppc-dev@ozlabs.org Subject: kernel panics with crashkernel=256M while booting Date: Mon, 22 Dec 2008 16:14:17 +0530 User-Agent: KMail/1.9.10 MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200812221614.17952.chandru@in.ibm.com> X-BeenThere: linuxppc-dev@ozlabs.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org On a ppc64 machine booting linux-2.6.28-rc9 with crashkernel=256M@32M boot parameter caused the kernel to panic while booting. Follwing is the console message.. ================================= ... Calling quiesce ... returning from prom_init Reserving 256MB of memory at 32MB for crashkernel (System RAM: 4096MB) Phyp-dump disabled at boot time Using pSeries machine description Using 1TB segments Found initrd at 0xc000000000e00000:0xc0000000015ab50c console [udbg0] enabled Partition configured for 4 cpus. CPU maps initialized for 2 threads per core Starting Linux PPC64 #3 SMP Mon Dec 22 02:16:31 CST 2008 ----------------------------------------------------- ppc64_pft_size = 0x1a physicalMemorySize = 0x100000000 htab_hash_mask = 0x7ffff ----------------------------------------------------- Initializing cgroup subsys cpuset Initializing cgroup subsys cpu Linux version 2.6.28-rc9-1-ppc64 (root@rulerlp10) (gcc version 4.3.2 [gcc-4_3-branch revision 141291] (SUSE Linux) ) #3 SMP Mon Dec 22 02:16:31 CST 2008 [boot]0012 Setup Arch ------------[ cut here ]------------ kernel BUG at mm/bootmem.c:279! Oops: Exception in kernel mode, sig: 5 [#1] SMP NR_CPUS=1024 NUMA pSeries Modules linked in: NIP: c000000000747538 LR: c000000000731d1c CTR: c000000000730cf4 REGS: c000000000993a00 TRAP: 0700 Not tainted (2.6.28-rc9-1-ppc64) MSR: 8000000000021032 CR: 24002082 XER: 00000001 TASK = c0000000008dfaa0[0] 'swapper' THREAD: c000000000990000 CPU: 0 GPR00: 0000000000000001 c000000000993c80 c00000000098a768 c0000000007664d0 GPR04: 00000000000001f7 0000000000001001 0000000000000001 0000000000000000 GPR08: 0000000000000000 0000000000000000 c0000000008dd6c0 0000000000000000 GPR12: 0000000024002088 c000000000a52c00 c000000000763990 c00000000067f735 GPR16: 00000000034638c8 0000000000000000 c000000000993d98 c000000000993d90 GPR20: c000000000993da0 c000000000c32bc8 c000000001f78800 c000000000000000 GPR24: 0000000000000004 0000000010087800 0000000000000000 0000000000000001 GPR28: 00000000000001f7 0000000000001001 c000000000910cb0 c0000000007664d0 NIP [c000000000747538] .mark_bootmem_node+0xa8/0x120 LR [c000000000731d1c] .do_init_bootmem+0xc1c/0xd58 Call Trace: [c000000000993c80] [c000000000993d20] init_thread_union+0x3d20/0x4000 (unreliable) [c000000000993d20] [c000000000731d1c] .do_init_bootmem+0xc1c/0xd58 [c000000000993e40] [c0000000007267f0] .setup_arch+0x1a4/0x21c [c000000000993ee0] [c000000000720868] .start_kernel+0xdc/0x56c [c000000000993f90] [c0000000000083b8] .start_here_common+0x1c/0x64 Instruction dump: 7ca501d2 4bda924d 60000000 e93f0000 7c09e010 7c000110 7c0000d0 0b000000 e81f0008 7c1d0010 7c000110 7c0000d0 <0b000000> 2fbb0000 7ca9e850 7c89e050 ---[ end trace 31fd0ba7d8756001 ]--- Kernel panic - not syncing: Attempted to kill the idle task! ------------[ cut here ]------------ Badness at kernel/smp.c:333 NIP: c0000000000b9384 LR: c0000000000b96ac CTR: 0000000000136f8c REGS: c000000000992eb0 TRAP: 0700 Tainted: G D (2.6.28-rc9-1-ppc64) MSR: 8000000000021032 CR: 28002084 XER: 00000001 TASK = c0000000008dfaa0[0] 'swapper' THREAD: c000000000990000 CPU: 0 GPR00: 0000000000000001 c000000000993130 c00000000098a768 0000000000000001 GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 0000000028002082 c000000000a52c00 c000000000763990 c00000000067f735 GPR16: 00000000034638c8 0000000000000000 c000000000993d98 c000000000993d90 GPR20: c000000000993da0 c000000000c32bc8 c000000001f78800 0000000000000000 GPR24: c000000000926320 0000000000000000 0000000000000000 0000000000000000 GPR28: 0000000000000000 0000000000000000 c00000000090f4f8 c000000000af8380 NIP [c0000000000b9384] .smp_call_function_mask+0x6c/0x2f4 LR [c0000000000b96ac] .smp_call_function+0xa0/0xcc Call Trace: [c000000000993130] [c0000000009931d0] init_thread_union+0x31d0/0x4000 (unreliable) [c000000000993420] [c0000000000b96ac] .smp_call_function+0xa0/0xcc [c000000000993530] [c00000000002ce0c] .smp_send_stop+0x24/0x3c [c0000000009935b0] [c0000000004f0658] .panic+0x98/0x198 [c000000000993640] [c00000000008fe18] .do_exit+0xa0/0x900 [c000000000993730] [c000000000027984] .die+0x274/0x278 [c0000000009937d0] [c000000000027c78] ._exception+0x88/0x20c [c000000000993990] [c000000000004f8c] program_check_common+0x10c/0x180 --- Exception: 700 at .mark_bootmem_node+0xa8/0x120 LR = .do_init_bootmem+0xc1c/0xd58 [c000000000993c80] [c000000000993d20] init_thread_union+0x3d20/0x4000 (unreliable) [c000000000993d20] [c000000000731d1c] .do_init_bootmem+0xc1c/0xd58 [c000000000993e40] [c0000000007267f0] .setup_arch+0x1a4/0x21c [c000000000993ee0] [c000000000720868] .start_kernel+0xdc/0x56c [c000000000993f90] [c0000000000083b8] .start_here_common+0x1c/0x64 Instruction dump: eae103a8 eb4103b6 f8810328 f8a10330 f8c10338 f8e10340 f9010348 f9210350 f9410358 880d01da 7c000074 7800d182 <0b000000> 3b8100d8 a3ad000a e89e8028 Rebooting in 180 seconds.. ================================= When booted with crashkernel=224M@32M or any memory size less than this, the system boots properly. The following was the observation.. The system comes up with two nodes (0-256M and 256M-4GB). The crashkernel memory reservation spans across these two nodes. The mark_reserved_regions_for_nid() in arch/powerpc/mm/numa.c resizes the reserved part of the memory within it as... ... ... if (end_pfn > node_ar.end_pfn) reserve_size = (node_ar.end_pfn << PAGE_SHIFT) - (start_pfn << PAGE_SHIFT); but the reserve_bootmem_node() in mm/bootmem.c raises the pfn value of end end = PFN_UP(physaddr + size); This causes end to get a value past the last page in the 0-256M node. Again when reserve_bootmem_node() returns, mark_reserved_regions_for_nid() loops around to set the rest of the crashkernel memory in the next node as reserved. It references NODE_DATA(node_ar.nid) and this causes another 'Oops: kernel access of bad area' problem. The following changes made the system to boot with any amount of crashkernel memory size. Fix code for reserved memory spanning acroos nodes Signed-off-by: Chandru S --- --- linux-2.6.28-rc9//arch/powerpc/mm/numa.c.orig 2008-12-22 04:23:24.000000000 -0600 +++ linux-2.6.28-rc9/arch/powerpc/mm/numa.c 2008-12-22 04:24:25.000000000 -0600 @@ -995,10 +995,11 @@ void __init do_init_bootmem(void) start_pfn, end_pfn); free_bootmem_with_active_regions(nid, end_pfn); + } + + for_each_online_node(nid) { /* - * Be very careful about moving this around. Future - * calls to careful_allocation() depend on this getting - * done correctly. + * Be very careful about moving this around. */ mark_reserved_regions_for_nid(nid); sparse_memory_present_with_active_regions(nid); --- linux-2.6.28-rc9/mm/bootmem.c.orig 2008-12-19 10:49:24.000000000 -0600 +++ linux-2.6.28-rc9/mm/bootmem.c 2008-12-19 10:49:33.000000000 -0600 @@ -375,10 +375,14 @@ int __init reserve_bootmem_node(pg_data_ unsigned long size, int flags) { unsigned long start, end; + bootmem_data_t *bdata = pgdat->bdata; start = PFN_DOWN(physaddr); end = PFN_UP(physaddr + size); + if (end > bdata->node_low_pfn) + end = bdata->node_low_pfn; + return mark_bootmem_node(pgdat->bdata, start, end, 1, flags); }