All of lore.kernel.org
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	gregkh@linuxfoundation.org, rafael.j.wysocki@intel.com,
	toshi.kani@hp.com
Subject: Re: [RFC PATCH v5 1/2] Use lock_device_hotplug() in cpu_probe_store() and cpu_release_store()
Date: Mon, 21 Apr 2014 18:38:04 -0400	[thread overview]
Message-ID: <20140421223804.GD22730@htj.dyndns.org> (raw)
In-Reply-To: <1398072059.2755.41.camel@ThinkPad-T5421.cn.ibm.com>

Hello,

On Mon, Apr 21, 2014 at 05:20:59PM +0800, Li Zhong wrote:
> While auditing the usage of lock_device_hotplug_sysfs() for implementing
> it in another way in following patch, it seems to me that the code here
> is to add/remove device, and the files probe/release for cpu bus
> themselves won't be removed. 
> 
> So it seems to me there is no s_active related deadlock here, and we
> could just use lock_device_hotplug().

It may still cause issue if offlining ends up removing sysfs files or
gets involved with the same lock used during cpu hot[un]plug
operations (e.g. offlining racing against cpu hotunplug) and offlining
a cpu does remove files.  Has this change been tested?

Thanks.

-- 
tejun

  parent reply	other threads:[~2014-04-21 22:38 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-10  9:18 [RFC PATCH] Suppress a device hot remove related lockdep warning Li Zhong
2014-04-10 13:31 ` Tejun Heo
2014-04-11  4:10   ` [RFC PATCH v2] Use kernfs_break_active_protection() for device online store callbacks Li Zhong
2014-04-11 10:26     ` Tejun Heo
2014-04-14  7:47       ` [RFC PATCH v3] " Li Zhong
2014-04-14 20:13         ` Tejun Heo
2014-04-15  2:44           ` Li Zhong
2014-04-15 14:50             ` Tejun Heo
2014-04-16  1:41               ` Li Zhong
2014-04-16 15:17                 ` Tejun Heo
2014-04-17  3:05                   ` Li Zhong
2014-04-17 15:06                     ` Tejun Heo
2014-04-17  6:50                   ` [RFC PATCH v4] " Li Zhong
2014-04-17 15:17                     ` Tejun Heo
2014-04-18  8:33                       ` Li Zhong
2014-04-21  9:20                       ` [RFC PATCH v5 1/2] Use lock_device_hotplug() in cpu_probe_store() and cpu_release_store() Li Zhong
2014-04-21  9:23                         ` [RFC PATCH v5 2/2] Use kernfs_break_active_protection() for device online store callbacks Li Zhong
2014-04-21 22:46                           ` Tejun Heo
2014-04-22  3:34                             ` Li Zhong
2014-04-22 10:11                               ` Rafael J. Wysocki
2014-04-23  1:50                                 ` Li Zhong
2014-04-23 10:54                                   ` Rafael J. Wysocki
2014-04-24  1:13                                     ` Li Zhong
2014-04-22 20:44                               ` Tejun Heo
2014-04-22 22:21                                 ` Rafael J. Wysocki
2014-04-23 14:23                                   ` Tejun Heo
2014-04-23 16:12                                     ` Rafael J. Wysocki
2014-04-23 16:52                                       ` Tejun Heo
2014-04-24  8:59                                       ` Li Zhong
2014-04-24 10:02                                         ` Rafael J. Wysocki
2014-04-25  1:46                                           ` Li Zhong
2014-04-25 12:47                                             ` Rafael J. Wysocki
2014-04-28  1:49                                               ` Li Zhong
2014-04-23  5:03                                 ` Li Zhong
2014-04-23 10:58                                   ` Rafael J. Wysocki
2014-04-24  1:33                                     ` Li Zhong
2014-05-09  8:35                               ` Li Zhong
2014-05-09  8:40                                 ` [RFC PATCH v6 1/2 ] Use lock_device_hotplug() in cpu_probe_store() and cpu_release_store() Li Zhong
2014-05-09  8:40                                   ` [RFC PATCH v6 2/2] Implement lock_device_hotplug_sysfs() by breaking active protection Li Zhong
2014-04-21 22:38                         ` Tejun Heo [this message]
2014-04-22  2:29                           ` [RFC PATCH v5 1/2] Use lock_device_hotplug() in cpu_probe_store() and cpu_release_store() Li Zhong
2014-04-22 20:40                             ` Tejun Heo
2014-04-23  2:00                               ` Li Zhong
2014-04-23 14:39                                 ` Tejun Heo
2014-04-24  8:37                                   ` Li Zhong
2014-04-24 14:32                                     ` Tejun Heo
2014-04-25  1:56                                       ` Li Zhong
2014-04-25 12:28                                         ` Tejun Heo
2014-04-28  0:51                                           ` Li Zhong

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=20140421223804.GD22730@htj.dyndns.org \
    --to=tj@kernel.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rafael.j.wysocki@intel.com \
    --cc=toshi.kani@hp.com \
    --cc=zhong@linux.vnet.ibm.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 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.