9:25 a.m.
Hi Dave,
OK, makes sense. I still spend 95% of my time in the RHEL 5 kernels so it's just lack
of enough time in the RHEL 6 kernels.
I did not have the debuginfo so I built a vmkernel with debug from source and used that. I
was able to get what I wanted out of the dump, specifically needed to look at the net_dev
structures.
Is there a write up somewhere on changes with crash for the 2.6.32.x kernels that you can
share.
Thanks
Laurence
-----Original Message-----
From: crash-utility-bounces(a)redhat.com [mailto:crash-utility-bounces@redhat.com] On Behalf
Of Dave Anderson
Sent: Wednesday, June 20, 2012 9:22 AM
To: Discussion list for crash utility usage, maintenance and development
Subject: Re: [Crash-utility] Pages excluded in dump RHEL 6.2 - set to ffffffffffffffff
----- Original Message -----
I have a dump from RHEL 6.2 with all these masks set to all f's,
so
obviously crash excludes them.
crash: page excluded: kernel virtual address: ffffffffffffffff type:
"possible"
WARNING: cannot read cpu_possible_map
crash: page excluded: kernel virtual address: ffffffffffffffff type:
"present"
WARNING: cannot read cpu_present_map
crash: page excluded: kernel virtual address: ffffffffffffffff type: "online"
WARNING: cannot read cpu_online_map
typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
/* These strip const, as traditionally they weren't const. */
#define cpu_possible_map (*(cpumask_t *)cpu_possible_mask)
#define cpu_online_map (*(cpumask_t *)cpu_online_mask)
#define cpu_present_map (*(cpumask_t *)cpu_present_mask)
#define cpu_active_map (*(cpumask_t *)cpu_active_mask)
Are these deprecated now and is that why they are fixed at all f's.
No, that's just a common error message for accessing the maps or masks.
When reading them, crash checks first whether there is the older kernel symbol named
"cpu_xxx_map", and if it doesn't exists, then it checks for the symbol named
"cpu_xxx_mask". It then tried to read the memory that those symbols point to,
which all contained values of ffffffffffffffff. So clearly there's some kind of
mis-match between the symbol values -- modified by using a System.map file -- and
what's in the vmcore file.
(FWIW, the dumpfile couldn't find the page for bogus address, and presumed that it was
"excluded" since it's a filtered dump, so that's a non-issue...)
First question: it appears that you are analyzing a RHEL6 kernel, so why are you using a
"System.map" argument? Did you rebuild the kernel but when you did that, you
didn't save the rebuilt vmlinux file?
Dave
[root@centos62 crash]# crash System.map vmlinux
va102.2012-06-14.vmcore
crash 6.0.7
Copyright (C) 2002-2012 Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation Copyright (C)
1999-2006 Hewlett-Packard Co Copyright (C) 2005, 2006, 2011, 2012
Fujitsu Limited Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011 NEC Corporation Copyright (C) 1999, 2002,
2007 Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public
License, and you are welcome to change it and/or distribute copies of
it under certain conditions. Enter "help copying" to see the conditions.
This program has absolutely no warranty. Enter "help warranty" for
details.
GNU gdb (GDB) 7.3.1
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu"...
crash: page excluded: kernel virtual address: ffffffffffffffff type:
"possible"
WARNING: cannot read cpu_possible_map
crash: page excluded: kernel virtual address: ffffffffffffffff type:
"present"
WARNING: cannot read cpu_present_map
crash: page excluded: kernel virtual address: ffffffffffffffff type: "online"
WARNING: cannot read cpu_online_map
crash: page excluded: kernel virtual address: ffffffffffffffff type:
"cpu_present_map"
crash: page excluded: kernel virtual address: ffffffffffffffff type:
"cpu_present_map"
crash: page excluded: kernel virtual address: ffffffffffffffff type:
"cpu_online_map"
SYSTEM MAP: System.map
DEBUG KERNEL: vmlinux (2.6.32-220.7.1.el6)
DUMPFILE: va102.2012-06-14.vmcore [PARTIAL DUMP]
CPUS: 32
DATE: Thu Jun 14 05:24:17 2012
UPTIME: 11:13:23
LOAD AVERAGE: 215.00, 196.78, 135.81
TASKS: 1778
NODENAME: va1splunkindex02.va1.swtor.int
RELEASE: 2.6.32-220.7.1.el6.x86_64
VERSION: #1 SMP Tue Mar 6 13:54:51 EST 2012
MACHINE: x86_64 (2799 Mhz)
MEMORY: 48 GB
PANIC: "Oops: 0002 [#1] SMP " (check log for details)
PID: 2428
COMMAND: "bash"
TASK: ffff88063874ab40 [THREAD_INFO: ffff8806dcd1a000]
CPU: 0
STATE: TASK_RUNNING (PANIC)
Thanks
Laurence
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