All of lore.kernel.org
 help / color / mirror / Atom feed
From: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: Tejun Heo <tj@kernel.org>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>,
	<linux-kernel@vger.kernel.org>, <laijs@cn.fujitsu.com>,
	<isimatu.yasuaki@jp.fujitsu.com>, <tangchen@cn.fujitsu.com>,
	<izumi.taku@jp.fujitsu.com>
Subject: Re: [PATCH 0/2] workqueue: fix a bug when numa mapping is changed
Date: Wed, 1 Apr 2015 11:55:11 +0900	[thread overview]
Message-ID: <551B5E0F.1020302@jp.fujitsu.com> (raw)
In-Reply-To: <20150331152822.GE9974@htj.duckdns.org>

On 2015/04/01 0:28, Tejun Heo wrote:
> Hello, Kamezawa.
>
> On Tue, Mar 31, 2015 at 03:09:05PM +0900, Kamezawa Hiroyuki wrote:
>> But this may be considered as API change for most hot-add users.
>
> Hmm... Why would it be?  What can that possibly break?
>

Now, hot-added cpus will have the lowest free cpu id.

Because of this, in most of systems which has only cpu-hot-add, cpu-ids are always
contiguous even after cpu hot add.
In enterprise, this would be considered as imcompatibility.

determining cpuid <-> lapicid at boot will make cpuids sparse. That may corrupt
exisiting script or configuration/resource management software.

>> So, for now, I vote for detemining ids at online but record it is a good way.
>
> If we know the information during boot, let's please do it at boot
> time by all means.

I basically agree. Just thinking influence of this small imcompatibility of forcing
ideal way because of my standing point.

Thanks,
-Kame


  reply	other threads:[~2015-04-01  2:55 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-26  2:17 [PATCH 0/2] workqueue: fix a bug when numa mapping is changed Gu Zheng
2015-03-26  2:17 ` [PATCH 1/2] x86/cpu hotplug: make apicid <--> cpuid mapping persistent Gu Zheng
2015-03-26  3:19   ` Kamezawa Hiroyuki
2015-03-26  4:55     ` Gu Zheng
2015-03-26 15:13       ` Tejun Heo
2015-03-26 16:31       ` Kamezawa Hiroyuki
2015-03-30  9:58         ` Gu Zheng
2015-04-01  2:59           ` Kamezawa Hiroyuki
2015-03-26  2:17 ` [PATCH 2/2] workqueue: update per cpu workqueue's numa affinity when cpu preparing online Gu Zheng
2015-03-26  3:12 ` [PATCH 0/2] workqueue: fix a bug when numa mapping is changed Kamezawa Hiroyuki
2015-03-26  5:04   ` Gu Zheng
2015-03-26 15:18     ` Tejun Heo
2015-03-26 16:42       ` Kamezawa Hiroyuki
2015-03-30  9:49         ` Gu Zheng
2015-03-30  9:49         ` Gu Zheng
2015-03-31  6:09           ` Kamezawa Hiroyuki
2015-03-31 15:28             ` Tejun Heo
2015-04-01  2:55               ` Kamezawa Hiroyuki [this message]
2015-04-01  3:02                 ` Tejun Heo
2015-04-01  3:05                   ` Tejun Heo
2015-04-01  8:30                   ` Kamezawa Hiroyuki
2015-04-02  1:36                     ` Gu Zheng
2015-04-02  2:54                       ` Kamezawa Hiroyuki

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=551B5E0F.1020302@jp.fujitsu.com \
    --to=kamezawa.hiroyu@jp.fujitsu.com \
    --cc=guz.fnst@cn.fujitsu.com \
    --cc=isimatu.yasuaki@jp.fujitsu.com \
    --cc=izumi.taku@jp.fujitsu.com \
    --cc=laijs@cn.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tangchen@cn.fujitsu.com \
    --cc=tj@kernel.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.