Reply-To: zhenzhong.duan@oracle.com
Subject: Re: Question with maxcpus= parameter.
References: <563C3980.8060405@oracle.com>
 <20151106065755.GA62424@otc-brkl-03.jf.intel.com>
To: "Raj, Ashok" <ashok.raj@intel.com>
Cc: rusty@rustcorp.com.au, LKML <linux-kernel@vger.kernel.org>,
        Feng Jin <joe.jin@oracle.com>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
From: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Organization: Oracle
Message-ID: <563C46A0.3040608@oracle.com>
Date: Fri, 6 Nov 2015 14:20:16 +0800
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101
 Thunderbird/38.3.0
MIME-Version: 1.0
In-Reply-To: <20151106065755.GA62424@otc-brkl-03.jf.intel.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1539
Lines: 47

Thanks for your quick response, Raj.

It's OL6 compatible with rhel6.

zduan
在 2015/11/6 14:57, Raj, Ashok 写道:
> Hi Zduan
>
> do you know which distribution it is? This isn't a kernel bug.
>
> if you look at dmesg you should see how many CPUs were booted. But the sysfs
> files are created and the usermode script is bringing every cpu online.
>
> Tony mentioned this to me couple weeks ago when i was fixing another bug
> in maxcpus. I think you can safely remove the script and it should be fine.
>
> Cheers,
> Ashok
>
>
> On Fri, Nov 06, 2015 at 01:24:16PM +0800, Zhenzhong Duan wrote:
>> 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/