Re: [Crash-utility] [PATCH] Display online cpus value in preference to kt->cpus
On Mon, 2010-03-08 at 21:23 +0000, Luciano Chavez wrote:
On Mon, 2010-03-08 at 20:30 +0000, Luciano Chavez wrote:
> On Mon, 2010-03-08 at 14:52 -0500, Dave Anderson wrote:
> >
> > For now, all I was thinking would be to simply change display_sys_stats()
> > to something like:
> >
> > if (machine_type("PPC64"))
> > your_function();
> > else
> > fprintf(fp, " CPUS: %d\n", kt->cpus);
> >
> > and since your_function() does not need to be in a machine-specific
> > file, just put in kernel.c. And you can also call it from the
> > ppc64_display_machine_stats() function.
>
> Hi Dave,
>
> I like this particular solution best! Simple and straightforward. I'll
> work on a patch that does exactly as suggested. I'll post it for review
> once I have it done this afternoon. Thanks for the help!
Below is the simpler revised patch. It applies and compiles to the
latest crash 5.0.1 source cleanly.
I still need to verify it still fixes the original problem. I am
confident it will but just wanted to post the patch up first.
BTW, I was able to briefly access a POWER7 box this morning and
confirmed that at least the CPU count displayed would be worse on one of
those systems if indeed SMT was disabled and when using the current code
minus the patch.
~ # cat /sys/devices/system/cpu/online
0-23
~ # ppc64_cpu --smt=off
~ # cat /sys/devices/system/cpu/online
0,4,8,12,16,20
The current 5.0.1 code would display CPUS: 21 rather than CPUS: 6
Once I confirm the patch fixes this problem, I will post a followup.
I tested the patch and confirmed it displayed the expected results after
disabling smt on a ppc64 test system. Previously, CPUS
count would have been displayed incorrectly as 15 on this test system.
[root@elm3b130 crash-5.0.1]# ppc64_cpu --smt=on
[root@elm3b130 crash-5.0.1]# cat /sys/devices/system/cpu/cpu*/online | grep -c 1
16
[root@elm3b130 crash-5.0.1]# ppc64_cpu --smt=off
[root@elm3b130 crash-5.0.1]# cat /sys/devices/system/cpu/cpu*/online | grep -c 1
8
[root@elm3b130 crash-5.0.1]# ./crash
crash 5.0.1
Copyright (C) 2002-2010 Red Hat, Inc.
Copyright (C) 2004, 2005, 2006 IBM Corporation
Copyright (C) 1999-2006 Hewlett-Packard Co
Copyright (C) 2005, 2006 Fujitsu Limited
Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
Copyright (C) 2005 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.
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This is free software: you are free to change and redistribute it.
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This GDB was configured as "powerpc64-unknown-linux-gnu"...
KERNEL: /usr/lib/debug/lib/modules/2.6.18-190.el5/vmlinux
DUMPFILE: /dev/mem
CPUS: 8
DATE: Mon Mar 8 18:36:44 2010
UPTIME: 01:49:41
LOAD AVERAGE: 0.54, 0.54, 0.36
TASKS: 176
NODENAME: elm3b130
RELEASE: 2.6.18-190.el5
VERSION: #1 SMP Mon Feb 22 19:18:34 EST 2010
MACHINE: ppc64 (1654 Mhz)
MEMORY: 4 GB
PID: 20625
COMMAND: "crash"
TASK: c000000090456c00 [THREAD_INFO: c0000000ceb84000]
CPU: 14
STATE: TASK_RUNNING (ACTIVE)
crash> sys
KERNEL: /usr/lib/debug/lib/modules/2.6.18-190.el5/vmlinux
DUMPFILE: /dev/mem
CPUS: 8
DATE: Mon Mar 8 18:36:49 2010
UPTIME: 01:49:45
LOAD AVERAGE: 0.50, 0.53, 0.36
TASKS: 177
NODENAME: elm3b130
RELEASE: 2.6.18-190.el5
VERSION: #1 SMP Mon Feb 22 19:18:34 EST 2010
MACHINE: ppc64 (1654 Mhz)
MEMORY: 4 GB
crash>
--
Luciano Chavez <lnx1138(a)linux.vnet.ibm.com>
IBM Linux Technology Center