From: "H. Peter Anvin" <hpa@zytor.com>
To: Tejun Heo <tj@kernel.org>
Cc: Toshi Kani <toshi.kani@hp.com>,
Zhang Yanfei <zhangyanfei.yes@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Rafael J . Wysocki" <rjw@sisk.pl>,
lenb@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
mingo@elte.hu, Wanpeng Li <liwanp@linux.vnet.ibm.com>,
Thomas Renninger <trenn@suse.de>, Yinghai Lu <yinghai@kernel.org>,
Jiang Liu <jiang.liu@huawei.com>,
Wen Congyang <wency@cn.fujitsu.com>,
Lai Jiangshan <laijs@cn.fujitsu.com>,
isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com,
Mel Gorman <mgorman@suse.de>, Minchan Kim <minchan@kernel.org>,
mina86@mina86.com, gong.chen@linux.intel.com,
vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com,
Rik van Riel <riel@redhat.com>,
jweiner@redhat.com, prarit@redhat.com,
"x86@kernel.org" <x86@kernel.org>,
linux-doc@vger.kernel.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linux MM <linux-mm@kvack.org>,
linux-acpi@vger.kernel.org, imtangchen@gmail.com,
Zhang Yanfei <zhangyanfei@cn.fujitsu.com>,
Tang Chen <tangchen@cn.fujitsu.com>
Subject: Re: [PATCH part1 v6 4/6] x86/mem-hotplug: Support initialize page tables in bottom-up
Date: Wed, 09 Oct 2013 14:14:24 -0700 [thread overview]
Message-ID: <5255C730.90602@zytor.com> (raw)
In-Reply-To: <20131009211136.GH5592@mtj.dyndns.org>
On 10/09/2013 02:11 PM, Tejun Heo wrote:
> Hello, Toshi.
>
> On Wed, Oct 09, 2013 at 02:58:31PM -0600, Toshi Kani wrote:
>> Let's not assume that memory hotplug is always a niche feature for huge
>> & special systems. It may be a niche to begin with, but it could be
>> supported on VMs, which allows anyone to use. Vasilis has been working
>> on KVM to support memory hotplug.
>
> I'm not saying hotplug will always be niche. I'm saying the approach
> we're currently taking is. It seems fairly inflexible to hang the
> whole thing on NUMA nodes. What does the planned kvm support do?
> Splitting SRAT nodes so that it can do both actual NUMA node
> distribution and hotplug granuliarity? IIRC I asked a couple times
> what the long term plan was for this feature and there doesn't seem to
> be any road map for this thing to become a full solution. Unless I
> misunderstood, this is more of "let's put out the fire as there
> already are (or gonna be) machines which can do it" kinda thing, which
> is fine too. My point is that it doesn't make a lot of sense to
> change boot sequence invasively to accomodate that.
>
I would also argue that in the VM scenario -- and arguable even in the
hardware scenario -- the right thing is to not expose the flexible
memory in the e820/EFI tables, and instead have it hotadded (possibly
*immediately* so) on boot. This avoids both the boot time funnies as
well as the scaling issues with metadata.
The whole reason for VMs wanting this is because ballooning doesn't
scale with regards to metadata.
-hpa
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-10-09 21:19 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-04 1:56 [PATCH part1 v6 0/6] x86, memblock: Allocate memory near kernel image before SRAT parsed Zhang Yanfei
2013-10-04 1:57 ` [PATCH part1 v6 1/6] memblock: Factor out of top-down allocation Zhang Yanfei
2013-10-04 1:58 ` [PATCH part1 v6 2/6] memblock: Introduce bottom-up allocation mode Zhang Yanfei
2013-10-05 21:30 ` Toshi Kani
2013-10-04 1:59 ` [PATCH part1 v6 3/6] x86/mm: Factor out of top-down direct mapping setup Zhang Yanfei
2013-10-04 2:00 ` [PATCH part1 v6 4/6] x86/mem-hotplug: Support initialize page tables in bottom-up Zhang Yanfei
2013-10-05 22:09 ` Toshi Kani
2013-10-07 0:00 ` H. Peter Anvin
2013-10-07 14:17 ` Zhang Yanfei
2013-10-08 17:36 ` Zhang Yanfei
2013-10-09 16:44 ` Tejun Heo
2013-10-09 17:14 ` Zhang Yanfei
2013-10-09 19:20 ` Tejun Heo
2013-10-09 19:30 ` Dave Hansen
2013-10-09 19:47 ` Tejun Heo
2013-10-09 20:58 ` Toshi Kani
2013-10-09 21:11 ` Tejun Heo
2013-10-09 21:14 ` H. Peter Anvin [this message]
2013-10-09 21:45 ` Zhang Yanfei
2013-10-09 23:10 ` H. Peter Anvin
2013-10-09 23:26 ` Zhang Yanfei
2013-10-10 1:20 ` Zhang Yanfei
2013-10-10 0:25 ` Toshi Kani
2013-10-09 23:58 ` Toshi Kani
2013-10-10 1:00 ` Tejun Heo
2013-10-10 14:36 ` Toshi Kani
2013-10-10 15:35 ` Tejun Heo
2013-10-10 16:24 ` Toshi Kani
2013-10-10 16:46 ` Tejun Heo
2013-10-10 16:50 ` Toshi Kani
2013-10-10 16:55 ` Tejun Heo
2013-10-10 16:59 ` Toshi Kani
2013-10-10 17:12 ` H. Peter Anvin
2013-10-10 19:17 ` Toshi Kani
2013-10-10 22:19 ` Tejun Heo
2013-10-10 23:00 ` Toshi Kani
2013-10-09 21:19 ` Zhang Yanfei
2013-10-09 21:22 ` H. Peter Anvin
2013-10-09 23:30 ` Zhang Yanfei
2013-10-09 19:10 ` Yinghai Lu
2013-10-09 19:23 ` Tejun Heo
2013-10-11 5:27 ` Yinghai Lu
2013-10-11 5:47 ` Zhang Yanfei
2013-10-11 6:33 ` Ingo Molnar
2013-10-11 6:46 ` Zhang Yanfei
2013-10-04 2:01 ` [PATCH part1 v6 5/6] x86, acpi, crash, kdump: Do reserve_crashkernel() after SRAT is parsed Zhang Yanfei
2013-10-05 22:10 ` Toshi Kani
2013-10-04 2:02 ` [PATCH part1 v6 6/6] mem-hotplug: Introduce movable_node boot option Zhang Yanfei
2013-10-05 22:28 ` Toshi Kani
2013-10-06 14:43 ` [PATCH part1 v6 update " Zhang Yanfei
2013-10-06 23:03 ` Toshi Kani
2013-10-08 4:23 ` [PATCH part1 v6 0/6] x86, memblock: Allocate memory near kernel image before SRAT parsed Ingo Molnar
2013-10-08 15:28 ` Zhang Yanfei
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5255C730.90602@zytor.com \
--to=hpa@zytor.com \
--cc=akpm@linux-foundation.org \
--cc=gong.chen@linux.intel.com \
--cc=imtangchen@gmail.com \
--cc=isimatu.yasuaki@jp.fujitsu.com \
--cc=izumi.taku@jp.fujitsu.com \
--cc=jiang.liu@huawei.com \
--cc=jweiner@redhat.com \
--cc=laijs@cn.fujitsu.com \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=liwanp@linux.vnet.ibm.com \
--cc=lwoodman@redhat.com \
--cc=mgorman@suse.de \
--cc=mina86@mina86.com \
--cc=minchan@kernel.org \
--cc=mingo@elte.hu \
--cc=prarit@redhat.com \
--cc=riel@redhat.com \
--cc=rjw@sisk.pl \
--cc=tangchen@cn.fujitsu.com \
--cc=tglx@linutronix.de \
--cc=tj@kernel.org \
--cc=toshi.kani@hp.com \
--cc=trenn@suse.de \
--cc=vasilis.liaskovitis@profitbricks.com \
--cc=wency@cn.fujitsu.com \
--cc=x86@kernel.org \
--cc=yinghai@kernel.org \
--cc=zhangyanfei.yes@gmail.com \
--cc=zhangyanfei@cn.fujitsu.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox