From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp08.in.ibm.com (e28smtp08.in.ibm.com [122.248.162.8]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id E896F2C00B0 for ; Thu, 20 Feb 2014 05:02:11 +1100 (EST) Received: from /spool/local by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 19 Feb 2014 23:32:05 +0530 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 6541F1258054 for ; Wed, 19 Feb 2014 23:34:02 +0530 (IST) Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s1JI23sJ8389082 for ; Wed, 19 Feb 2014 23:32:03 +0530 Received: from d28av04.in.ibm.com (localhost [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s1JI20Dj030311 for ; Wed, 19 Feb 2014 23:32:01 +0530 Date: Wed, 19 Feb 2014 23:32:00 +0530 From: Srikar Dronamraju To: Aneesh Kumar , riel@redhat.com, mgorman@suse.de Subject: Panic on ppc64 with numa_balancing and !sparsemem_vmemmap Message-ID: <20140219180200.GA29257@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Cc: Peter Zijlstra , paulus@samba.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org Reply-To: Srikar Dronamraju List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On a powerpc machine with CONFIG_NUMA_BALANCING=y and CONFIG_SPARSEMEM_VMEMMAP not enabled, kernel panics. This is true of kernel versions 3.13 to the latest commit 960dfc4 which is 3.14-rc3+. i.e the recent 3 fixups from Aneesh doesnt seem to help this case. Sometimes it fails on boot up itself. Otherwise a kernel compile is good enough to trigger the same. I am seeing this on a Power 7 box. Kernel 3.14.0-rc3-mainline_v313-00168-g960dfc4 on an ppc64 transam2s-lp1 login: qla2xxx [0003:01:00.1]-8038:2: Cable is unplugged... Unable to handle kernel paging request for data at address 0x00000457 Faulting instruction address: 0xc0000000000d6004 cpu 0x38: Vector: 300 (Data Access) at [c00000171561f700] pc: c0000000000d6004: .task_numa_fault+0x604/0xa30 lr: c0000000000d62fc: .task_numa_fault+0x8fc/0xa30 sp: c00000171561f980 msr: 8000000000009032 dar: 457 dsisr: 40000000 current = 0xc0000017155d9b00 paca = 0xc00000000ec1e000 softe: 0 irq_happened: 0x00 pid = 16898, comm = gzip enter ? for help [c00000171561fa70] c0000000001b0fb0 .do_numa_page+0x1b0/0x2a0 [c00000171561fb20] c0000000001b2788 .handle_mm_fault+0x538/0xca0 [c00000171561fc00] c00000000082f498 .do_page_fault+0x378/0x880 [c00000171561fe30] c000000000009568 handle_page_fault+0x10/0x30 --- Exception: 301 (Data Access) at 00000000100031d8 SP (3fffd45ea2d0) is in userspace 38:mon> (gdb) list *(task_numa_fault+0x604) 0xc0000000000d6004 is in task_numa_fault (/home/srikar/work/linux.git/include/linux/mm.h:753). 748 return cpupid_to_cpu(cpupid) == (-1 & LAST__CPU_MASK); 749 } 750 751 static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid) 752 { 753 return (task_pid & LAST__PID_MASK) == cpupid_to_pid(cpupid); 754 } 755 756 #define cpupid_match_pid(task, cpupid) __cpupid_match_pid(task->pid, cpupid) 757 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS (gdb) However this doesnt seem to happen if we have CONFIG_SPARSEMEM_VMEMMAP=y set in the config. -- Thanks nnn Regards Srikar Dronamraju