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From: Zhenzhong Duan <zhenzhong.duan@oracle.com>
To: rusty@rustcorp.com.au, ashok.raj@intel.com,
	LKML <linux-kernel@vger.kernel.org>
Cc: Feng Jin <joe.jin@oracle.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Question with maxcpus= parameter.
Date: Fri, 6 Nov 2015 13:24:16 +0800	[thread overview]
Message-ID: <563C3980.8060405@oracle.com> (raw)

Hi Maintainers,

Recently we faced an cpu online issue with maxcpus= parameter.

We want to have 4 cpus onlined at bootup, test 3.8.13-stable on an 72 
cpus env with maxcpus=4, I found more cpus than 4 are onlined.
It's the udev scripts make them onlined. But below script exist for a 
long time.
ACTION=="add", KERNEL=="cpu[0-9]*", RUN+="/bin/bash -c 'echo 1 > 
/sys/devices/system/cpu/%k/online'"

maxcpu= parameter didn't take effect, so is this a kernel bug? Or that 
script should be removed?

Btw: 2.6.39 works fine, I checked udev log, seems CPU ADD event is only 
sent for 4cpus.
Why the difference between 2.6.39 and 3.8.13?

thanks
zduan

             reply	other threads:[~2015-11-06  5:23 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-06  5:24 Zhenzhong Duan [this message]
2015-11-06  6:57 ` Question with maxcpus= parameter Raj, Ashok
2015-11-06  6:20   ` Zhenzhong Duan
     [not found] ` <20151106161459.GB4538@char.us.oracle.com>
2015-11-09  5:47   ` Zhenzhong Duan
2015-11-09  6:12     ` Yinghai Lu
2015-11-09  9:09       ` Zhenzhong Duan
2015-11-09 17:04         ` Yinghai Lu

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