On 11/10/18 at 8:59 AM, Waiman Long wrote:
> On 11/09/2018 08:45 PM, Qian Cai wrote: > >> Sent: Friday, November 09, 2018 at 5:08 PM > >> From: "Waiman Long" <long...@redhat.com> > >> To: "Qian Cai" <c...@gmx.us>, "Yang Shi" <yang....@linux.alibaba.com> > >> Cc: "open list" <linux-kernel@vger.kernel.org>, "Thomas Gleixner" > >> <t...@linutronix.de>, "Arnd Bergmann" <a...@arndb.de>, "Joel Fernandes > >> (Google)" <j...@joelfernandes.org>, "Zhong Jiang" <zhongji...@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....@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? > > First, I think you need to figure out what your system needed to use up > so many debug objects in early boot. If there is a legitimate reason for > this behavior, we can talk about having a kconfig option to increase that. Anybody else not getting ODEBUG OOM with more than 64-CPU? As mentioned, restricting to 16-CPU works fine. How can I figure out why the system uses so much debug objects?
