From: Borislav Petkov <petkovbb@googlemail.com>
To: zhiyi <zhuang@cs.otago.ac.nz>
Cc: linux-kernel@vger.kernel.org, Zhiyi Huang <hzy@cs.otago.ac.nz>
Subject: Re: nr_cpu_ids incorrect on AMD Quad-Core Opteron 8380
Date: Sat, 30 Jan 2010 18:18:04 +0100 [thread overview]
Message-ID: <20100130171804.GA2348@liondog.tnic> (raw)
In-Reply-To: <A1D71FDC-3176-4792-83ED-3ACAA3D61CFF@cs.otago.ac.nz>
On Thu, Jan 28, 2010 at 12:16:44PM +1300, zhiyi wrote:
> Hi,
> I have just found the value of nr_cpu_ids is 32, instead of 16 on my
> new Dell PowerEdge R905 which has 16 cpus (4 quad-core Opteron
> 8380). However, /proc/cpuinfo displays the right number (16).
> I have searched the archive but found no related subject. Is there
> any patch already available to fix the problem?
> I am using 2.6.31-4 and verified this incorrect value (32) using a
> module.
nr_cpu_ids is set to CONFIG_NR_CPUS on SMP kernels and denotes the max
CPUs supported by your kernel. This is not a bug but a configurable
option in the kernel for saving memory.
You can still set CONFIG_NR_CPUS in "-> Processor type and features" to
the max number of cores N you have on your machine if you want to save
approx 8*N KB. But guessing from your quadsocket configuration, memory
shouldn't be that scarce on that machine to go the trouble :).
--
Regards/Gruss,
Boris.
next prev parent reply other threads:[~2010-01-30 17:18 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-27 23:16 nr_cpu_ids incorrect on AMD Quad-Core Opteron 8380 zhiyi
2010-01-30 17:18 ` Borislav Petkov [this message]
2010-01-31 22:59 ` zhiyi
2010-02-01 13:57 ` Borislav Petkov
2010-02-01 15:04 ` Borislav Petkov
2010-02-02 0:49 ` zhiyi
2010-02-02 7:07 ` Borislav Petkov
2010-02-02 21:33 ` zhiyi
2010-02-03 7:21 ` Borislav Petkov
2010-02-02 0:35 ` zhiyi
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