From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: Tejun Heo <tj@kernel.org>,
Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"\"Ishimatsu, Yasuaki/石松 靖章\"" <isimatu.yasuaki@jp.fujitsu.com>,
"Tang Chen" <tangchen@cn.fujitsu.com>,
"guz.fnst@cn.fujitsu.com" <guz.fnst@cn.fujitsu.com>
Subject: Re: [PATCH 1/2] workqueue: update numa affinity info at node hotplug
Date: Tue, 13 Jan 2015 15:19:09 +0800 [thread overview]
Message-ID: <54B4C6ED.9060501@cn.fujitsu.com> (raw)
In-Reply-To: <20141225201156.GA22951@htj.dyndns.org>
On 12/26/2014 04:11 AM, Tejun Heo wrote:
> On Wed, Dec 17, 2014 at 01:56:29PM +0900, Kamezawa Hiroyuki wrote:
>> Let me correct my words. Main purpose of this patch 1/2 is handling a case "node disappers" after boot.
>> And try to handle physicall node hotplug caes.
>>
>> Changes of cpu<->node relationship at CPU_ONLINE is handled in patch 2/2.
>
> Can you please make numa code itself maintain the cpu to nodemask
> maps? Let's make workqueue a simple consumer of that and we don't
> have proper notification mechanism for node up/down events?
>
> Thanks.
>
The Mapping of the *online* cpus to nodes is already maintained by numa code.
What the workqueue needs is a special Mapping:
The Mapping of the *possible* cpus to nodes
But this mapping (if the numa code maintain it) is a trouble:
"possible" implies the mapping is stable/constant/immutable, it is hard to
ensure it in the numa code.
if mutability of this mapping is acceptable, we just move 20~40 LOC of code
from workqueue to numa code, all the other complexities about it are still in workqueue.c.
Thanks
Lai
next prev parent reply other threads:[~2015-01-13 7:18 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-16 16:36 [PATCH 0/2] workqueue: fix a bug when numa mapping is changed v4 Kamezawa Hiroyuki
2014-12-16 16:45 ` [PATCH 1/2] workqueue: update numa affinity info at node hotplug Kamezawa Hiroyuki
2014-12-17 1:36 ` Lai Jiangshan
2014-12-17 3:22 ` Kamezawa Hiroyuki
2014-12-17 4:56 ` Kamezawa Hiroyuki
2014-12-25 20:11 ` Tejun Heo
2015-01-13 7:19 ` Lai Jiangshan [this message]
2015-01-13 15:22 ` Tejun Heo
2015-01-14 2:47 ` Lai Jiangshan
2015-01-14 8:54 ` [RFC PATCH 0/2 shit_A shit_B] workqueue: fix wq_numa bug Lai Jiangshan
2015-01-14 8:54 ` [RFC PATCH 1/2 shit_A shit_B] workqueue: reset pool->node and unhash the pool when the node is offline Lai Jiangshan
2015-01-14 8:54 ` [RFC PATCH 2/2 shit_A] workqueue: update wq_numa when cpu_present_mask changed Lai Jiangshan
2015-01-14 8:54 ` [RFC PATCH 2/3 shit_B] workqueue: remove wq_numa_possible_cpumask Lai Jiangshan
2015-01-14 8:54 ` [RFC PATCH 3/3 shit_B] workqueue: directly update attrs of pools when cpu hot[un]plug Lai Jiangshan
2015-01-16 5:22 ` [RFC PATCH 0/2 shit_A shit_B] workqueue: fix wq_numa bug Yasuaki Ishimatsu
2015-01-16 8:04 ` Lai Jiangshan
2015-01-23 6:13 ` Izumi, Taku
2015-01-23 8:18 ` Lai Jiangshan
2015-01-14 13:57 ` [PATCH 1/2] workqueue: update numa affinity info at node hotplug Tejun Heo
2015-01-15 1:23 ` Lai Jiangshan
2014-12-16 16:51 ` [PATCH 2/2] workqueue: update cpumask at CPU_ONLINE if necessary 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=54B4C6ED.9060501@cn.fujitsu.com \
--to=laijs@cn.fujitsu.com \
--cc=guz.fnst@cn.fujitsu.com \
--cc=isimatu.yasuaki@jp.fujitsu.com \
--cc=kamezawa.hiroyu@jp.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome