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From:   "Qian Cai" <cai@gmx.us>
To:     "Waiman Long" <longman@redhat.com>
Cc:     "Joel Fernandes (Google)" <joel@joelfernandes.org>,
        "Yang Shi" <yang.shi@linux.alibaba.com>,
        "Zhong Jiang" <zhongjiang@huawei.com>,
        "Arnd Bergmann" <arnd@arndb.de>,
        "open list" <linux-kernel@vger.kernel.org>,
        "Thomas Gleixner" <tglx@linutronix.de>
Subject: Re: ODEBUG: Out of memory. ODEBUG disabled
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Date:   Sat, 10 Nov 2018 02:45:29 +0100
Sender: linux-kernel-owner@vger.kernel.org
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> Sent: Friday, November 09, 2018 at 5:08 PM
> From: "Waiman Long" <longman@redhat.com>
> To: "Qian Cai" <cai@gmx.us>, "Yang Shi" <yang.shi@linux.alibaba.com>
> Cc: "open list" <linux-kernel@vger.kernel.org>, "Thomas Gleixner" <tglx@linutronix.de>, "Arnd Bergmann" <arnd@arndb.de>, "Joel Fernandes (Google)" <joel@joelfernandes.org>, "Zhong Jiang" <zhongjiang@huawei.com>
> Subject: Re: ODEBUG: Out of memory. ODEBUG disabled
> 
> On 11/09/2018 04:51 PM, Qian Cai wrote:
>> 
>>> On Nov 9, 2018, at 4:42 PM, Yang Shi <yang.shi@linux.alibaba.com> wrote:
>>> 
>>> 
>>> 
>>> On 11/9/18 1:36 PM, Qian Cai wrote:
>>>> It is a bit annoying on this aarch64 server with 64 CPUs that is
>>>> booting the latest mainline (3541833fd1f2) causes object debugging
>>>> always running out of memory.
>>> May you please paste the detail failure log?
>> I assume you mean dmesg.
>> 
>> Here is the dmesg for 64 CPUs,
>> https://paste.ubuntu.com/p/BnhvXXhn7k/
>>>> I have to boot the kernel with only 16 CPUs instead (nr_cpus=16)
>>>> to make it work. Is it expected that object debugging is not going
>>>> to work with large machines?
>>> I don't think so. I'm supposed it works well with large CPU number on x86.
>> Here is the one with nr_cpus workaround,
>> https://paste.ubuntu.com/p/qMpd2CCPSV/
> 
> The debugobjects code have a set of 1024 statically allocated debug
> objects that can be used in early boot before the slab memory allocator
> is initialized. Apparently, the system may have used up all the
> statically allocated objects. Try double ODEBUG_POOL_SIZE to see if it
> helps.
Great, you are right. Doubling the size makes it work. Does it make sense
to have a kconfig option instead?
> 
> There are also quite a number of warnings in your console log. So there
> is certainly something wrong with your kernel or config options.
Yes, I am working on all those warnings. This one is found by ODEBUG,
https://lkml.org/lkml/2018/11/10/136