linux-kernel - Re: [PATCH 14/14] x86, mm: Put pagetable on local node ram

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAE9FiQWe_QbsmuJfqT+Wc77v7M0y1+ho-3ZpxV8b0er6tSTFKQ@mail.gmail.com>
Date:	Thu, 7 Mar 2013 23:44:18 -0800
From:	Yinghai Lu <yinghai@...nel.org>
To:	Tejun Heo <tj@...nel.org>
Cc:	Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...e.hu>,
	"H. Peter Anvin" <hpa@...or.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Thomas Renninger <trenn@...e.de>,
	Tang Chen <tangchen@...fujitsu.com>,
	linux-kernel@...r.kernel.org, Pekka Enberg <penberg@...nel.org>,
	Jacob Shin <jacob.shin@....com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Subject: Re: [PATCH 14/14] x86, mm: Put pagetable on local node ram

On Thu, Mar 7, 2013 at 11:01 PM, Tejun Heo <tj@...nel.org> wrote:
> On Thu, Mar 07, 2013 at 08:58:40PM -0800, Yinghai Lu wrote:
>> If node with ram is hotplugable, local node mem for page table and vmemmap
>> should be on that node ram.
>>
>> This patch is some kind of refreshment of
>> | commit 1411e0ec3123ae4c4ead6bfc9fe3ee5a3ae5c327
>> | Date:   Mon Dec 27 16:48:17 2010 -0800
>> |
>> |    x86-64, numa: Put pgtable to local node memory
>> That was reverted before.
>>
>> We have reason to reintroduce it to make memory hotplug work.
>>
>> Split calling of init_mem_mapping into early_initmem_info
>> for nodes after we get numa info there.
>>
>> First node will be low range.
>> Need to rework alloc_low_pages to alloc page table in following order:
>>       BRK, local node, low range
>>
>> Still only load_cr3 one time, otherwise we would break xen 64bit again.
>
> Hmmm... can you please split this patch further?  init_mem_mapping()
> change can be separated, no?

will try to split it out.

> Also, comments are disturbingly missing.
> How are other people reading the code supposed to know what it's
> trying to achieve why and how?  Hmmm... we're also likely to end up
> with smaller mapping for misaligned NUMA configurations (I think my
> test machine is like that).  Is it guaranteed that the top level ends
> up in the first node?  It really needs documentation.

Yes. To really memory hotplug working, will need to trim the node
alignment to be
1G in memblock and numa_meminfo.

also need to put pgd page in low range (first node) if 512G block is
crossing node.
for example: if node2 is [256g, 1024g), pgd for 256g-512g, must be stay on node0
and 512g-1024g could stay on node2.
or just put all PGD pages on low range (first node).

Thanks

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