Re: [Patch V2 2/2] x86/mm/numa: remove the numa_nodemask_from_meminfo()

From: Wei Yang <richard.weiyang@gmail.com>
To: Borislav Petkov <bp@alien8.de>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Tejun Heo <tj@kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [Patch V2 2/2] x86/mm/numa: remove the numa_nodemask_from_meminfo()
Date: Sun, 9 Apr 2017 11:12:14 +0800	[thread overview]
Message-ID: <CADZGycaQpigWOsDBikGgn_xJ9SXCA+WLRL_z=CHGiB4yi+GVYw@mail.gmail.com> (raw)
In-Reply-To: <20170406184838.z4pa4j33z2rp4mrg@pd.tnic>

On Fri, Apr 7, 2017 at 2:48 AM, Borislav Petkov <bp@alien8.de> wrote:
> On Thu, Apr 06, 2017 at 09:21:47PM +0300, Kirill A. Shutemov wrote:
>> > Long story short, something as trivial as this helps here:
>>
>> Yep. Works for me.
>>
>> Reported-and-tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
>
> Thanks.
>
> Now, I'd really like to have more test coverage and be sure this
> "cleanup" doesn't break anything else so Wei, please grab tip/master,
> apply the oneliner from two messages ago, take Kirill's qemu cmdline
> and run all fake numa scenarios you can think of to make sure your
> cleanup doesn't break anything else.
>

Oops, sorry to bring in the regression with my cleanup.
I haven't noticed there is a kernel command line "numa=fake", which
is the cause of the crash I think.

So from my understanding, I am goting to do these tests:

1. all fake numa scenarios with Kirill's qemu command line
2. Real numa scenarios with following qemu command option
3. Baremetal

One more question, on the baremetal mathine, I can't change the
numa configuration, so there would be only one case. Do you have
some specific requirement?

Well, if I missed something, just let me know :-)

> Qemu can emulate real numa too, for example you can boot with:
>
> -smp 64 \
> -numa node,nodeid=0,cpus=1-8 \
> -numa node,nodeid=1,cpus=9-16 \
> -numa node,nodeid=2,cpus=17-24 \
> -numa node,nodeid=3,cpus=25-32 \
> -numa node,nodeid=4,cpus=0 \
> -numa node,nodeid=4,cpus=33-39 \
> -numa node,nodeid=5,cpus=40-47 \
> -numa node,nodeid=6,cpus=48-55 \
> -numa node,nodeid=7,cpus=56-63
>
> after configuring the kernel accordingly.
>
> Then, test baremetal too.
>
> numa_emulation() should give you an idea about possible options
> numa=fake takes. Documentation/x86/x86_64/boot-options.txt has some
> (all?) too.
>
> Thanks.
>
> --
> Regards/Gruss,
>     Boris.
>
> Good mailing practices for 400: avoid top-posting and trim the reply.