linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Tang Chen <imtangchen@gmail.com>,
	Tang Chen <tangchen@cn.fujitsu.com>,
	robert.moore@intel.com, lv.zheng@intel.com, rjw@sisk.pl,
	lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu,
	hpa@zytor.com, akpm@linux-foundation.org, trenn@suse.de,
	yinghai@kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com,
	laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com,
	izumi.taku@jp.fujitsu.com, mgorman@suse.de, minchan@kernel.org,
	mina86@mina86.com, gong.chen@linux.intel.com,
	vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com,
	riel@redhat.com, jweiner@redhat.com, prarit@redhat.com,
	zhangyanfei@cn.fujitsu.com, yanghy@cn.fujitsu.com,
	x86@kernel.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	linux-acpi@vger.kernel.org
Subject: Re: [PATCH part5 0/7] Arrange hotpluggable memory as ZONE_MOVABLE.
Date: Wed, 14 Aug 2013 14:23:42 -0400	[thread overview]
Message-ID: <20130814182342.GG28628@htj.dyndns.org> (raw)
In-Reply-To: <520BC950.1030806@gmail.com>

Hello,

On Wed, Aug 14, 2013 at 02:15:44PM -0400, KOSAKI Motohiro wrote:
> I don't follow this. We need to think why memory hotplug is necessary.
> Because system reboot is unacceptable on several critical services. Then,
> if someone set wrong boot option, systems SHOULD fail to boot. At that time,
> admin have a chance to fix their mistake. In the other hand, after running
> production service, they have no chance to fix the mistake. In general, default
> boot option should have a fallback and non-default option should not have a
> fallback. That's a fundamental rule.

The fundamental rule is that the system has to boot.  Your argument is
pointless as the kernel has no control over where its own image is
placed w.r.t. hotpluggable nodes.  So, are we gonna fail boot if
kernel image intersects hotpluggable node and the option is specified
even if memory hotplug can be used on other nodes?  That doesn't make
any sense.

Failing to boot is *way* worse reporting mechanism than almost
everything else.  If the sysadmin is willing to risk machines failing
to come up, she would definitely be willing to check whether which
memory areas are actually hotpluggable too, right?

Thanks.

-- 
tejun

  reply	other threads:[~2013-08-14 18:23 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-08 10:16 [PATCH part5 0/7] Arrange hotpluggable memory as ZONE_MOVABLE Tang Chen
2013-08-08 10:16 ` [PATCH part5 1/7] x86: get pg_data_t's memory from other node Tang Chen
2013-08-12 14:39   ` Tejun Heo
2013-08-12 15:12     ` Tang Chen
2013-08-08 10:16 ` [PATCH part5 2/7] x86, numa, mem_hotplug: Skip all the regions the kernel resides in Tang Chen
2013-08-08 10:16 ` [PATCH part5 3/7] memblock, numa: Introduce flag into memblock Tang Chen
2013-08-08 10:16 ` [PATCH part5 4/7] memblock, mem_hotplug: Introduce MEMBLOCK_HOTPLUG flag to mark hotpluggable regions Tang Chen
2013-08-08 10:16 ` [PATCH part5 5/7] memblock, mem_hotplug: Make memblock skip hotpluggable regions by default Tang Chen
2013-08-14 21:54   ` Naoya Horiguchi
2013-08-15  5:15     ` Tang Chen
2013-08-08 10:16 ` [PATCH part5 6/7] mem-hotplug: Introduce movablenode boot option to {en|dis}able using SRAT Tang Chen
2013-08-08 10:16 ` [PATCH part5 7/7] x86, numa, acpi, memory-hotplug: Make movablenode have higher priority Tang Chen
2013-08-09 16:32 ` [PATCH part5 0/7] Arrange hotpluggable memory as ZONE_MOVABLE Tejun Heo
2013-08-12  8:54   ` Tang Chen
2013-08-12 14:50 ` Tejun Heo
2013-08-12 15:14   ` H. Peter Anvin
2013-08-12 15:23     ` Tejun Heo
2013-08-12 16:29       ` Tang Chen
2013-08-12 16:46         ` Tejun Heo
2013-08-12 18:23           ` Tang Chen
2013-08-12 20:20             ` Tejun Heo
2013-08-13  6:14           ` Tang Chen
2013-08-13  9:56             ` Tang Chen
2013-08-13 14:38               ` Tejun Heo
2013-08-12 15:41   ` Tang Chen
2013-08-12 15:46     ` Tejun Heo
2013-08-12 16:19       ` Tang Chen
2013-08-12 16:22         ` Tejun Heo
2013-08-12 17:01           ` Tang Chen
2013-08-12 17:23             ` H. Peter Anvin
2013-08-14 18:22               ` KOSAKI Motohiro
2013-08-12 18:07             ` Tejun Heo
2013-08-14 18:15               ` KOSAKI Motohiro
2013-08-14 18:23                 ` Tejun Heo [this message]
2013-08-14 19:40                   ` KOSAKI Motohiro
2013-08-14 19:55                     ` Tejun Heo
2013-08-14 20:29                       ` KOSAKI Motohiro
2013-08-14 20:30                         ` H. Peter Anvin
2013-08-14 20:35                         ` Tejun Heo
2013-08-14 21:17                           ` KOSAKI Motohiro
2013-08-14 21:36                             ` Tejun Heo
2013-08-15  1:08                               ` KOSAKI Motohiro
2013-08-15  1:21                                 ` Tejun Heo
2013-08-15  1:33                                   ` Tejun Heo
2013-08-15  1:44                                     ` KOSAKI Motohiro
2013-08-15  2:22                                       ` Tejun Heo
2013-08-15  1:38                                   ` KOSAKI Motohiro
2013-08-15  1:51                                     ` Tejun Heo

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=20130814182342.GG28628@htj.dyndns.org \
    --to=tj@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=gong.chen@linux.intel.com \
    --cc=hpa@zytor.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=kosaki.motohiro@gmail.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=lv.zheng@intel.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=robert.moore@intel.com \
    --cc=tangchen@cn.fujitsu.com \
    --cc=tglx@linutronix.de \
    --cc=trenn@suse.de \
    --cc=vasilis.liaskovitis@profitbricks.com \
    --cc=wency@cn.fujitsu.com \
    --cc=x86@kernel.org \
    --cc=yanghy@cn.fujitsu.com \
    --cc=yinghai@kernel.org \
    --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;
as well as URLs for NNTP newsgroup(s).