From: Tejun Heo <tj@kernel.org>
To: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
"Zhang, Qiang" <Qiang.Zhang@windriver.com>,
Markus Elfring <markus.elfring@web.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kernel-janitors@vger.kernel.org"
<kernel-janitors@vger.kernel.org>
Subject: Re: 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call
Date: Thu, 28 May 2020 14:03:57 +0000 [thread overview]
Message-ID: <20200528140357.GL83516@mtj.thefacebook.com> (raw)
In-Reply-To: <CAJhGHyBUkMZ=cV+Qf-5+PMAFqgebbRLc46OZSSUSgoRROpUk2A@mail.gmail.com>
Hello,
On Thu, May 28, 2020 at 09:27:03PM +0800, Lai Jiangshan wrote:
> wq owns the ultimate or permanent references to itself by
> owning references to wq->numa_pwq_tbl[node], wq->dfl_pwq.
> The pwq's references keep the pwq in wq->pwqs.
Yeah, regardless of who puts a wq the last time, the base reference is put
by destroy_workqueue() and thus it's guaranteed that a wq can't be rcu freed
without going through destroy_workqueue(). lol I'm undoing the revert.
Thanks.
--
tejun
WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj@kernel.org>
To: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
"Zhang, Qiang" <Qiang.Zhang@windriver.com>,
Markus Elfring <markus.elfring@web.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kernel-janitors@vger.kernel.org"
<kernel-janitors@vger.kernel.org>
Subject: Re: 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call in rcu_free_wq()
Date: Thu, 28 May 2020 10:03:57 -0400 [thread overview]
Message-ID: <20200528140357.GL83516@mtj.thefacebook.com> (raw)
In-Reply-To: <CAJhGHyBUkMZ=cV+Qf-5+PMAFqgebbRLc46OZSSUSgoRROpUk2A@mail.gmail.com>
Hello,
On Thu, May 28, 2020 at 09:27:03PM +0800, Lai Jiangshan wrote:
> wq owns the ultimate or permanent references to itself by
> owning references to wq->numa_pwq_tbl[node], wq->dfl_pwq.
> The pwq's references keep the pwq in wq->pwqs.
Yeah, regardless of who puts a wq the last time, the base reference is put
by destroy_workqueue() and thus it's guaranteed that a wq can't be rcu freed
without going through destroy_workqueue(). lol I'm undoing the revert.
Thanks.
--
tejun
next prev parent reply other threads:[~2020-05-28 14:03 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-27 7:57 [PATCH v5] workqueue: Remove unnecessary kfree() call in rcu_free_wq() qiang.zhang
2020-05-27 8:20 ` Markus Elfring
2020-05-27 8:20 ` Markus Elfring
[not found] ` <DM6PR11MB32573F3884A864ECD586235EFF8E0@DM6PR11MB3257.namprd11.prod.outlook.com>
2020-05-28 1:44 ` 回复: [PATCH v5] workqueue: Remove unnecessar =?gb2312?B?eSBrZnJlZSgpIGN Zhang, Qiang
2020-05-28 1:44 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call in rcu_free_wq() Zhang, Qiang
2020-05-28 9:57 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call Dan Carpenter
2020-05-28 9:57 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call in rcu_free_wq() Dan Carpenter
2020-05-28 10:38 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call Tejun Heo
2020-05-28 10:38 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call in rcu_free_wq() Tejun Heo
2020-05-28 11:00 ` [v5] " Markus Elfring
2020-05-28 11:00 ` Markus Elfring
2020-05-28 14:40 ` Markus Elfring
2020-05-28 14:40 ` Markus Elfring
2020-05-28 12:08 ` 回复: [PATCH v5] workqueue: Remove unnecessary =?UTF-8?B?IGtmc Lai Jiangshan
2020-05-28 12:08 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call in rcu_free_wq() Lai Jiangshan
2020-05-28 12:25 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call Dan Carpenter
2020-05-28 12:25 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call in rcu_free_wq() Dan Carpenter
2020-05-28 13:27 ` 回复: [PATCH v5] workqueue: Remove unnecessary =?UTF-8?B?IGtmc Lai Jiangshan
2020-05-28 13:27 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call in rcu_free_wq() Lai Jiangshan
2020-05-28 14:03 ` Tejun Heo [this message]
2020-05-28 14:03 ` Tejun Heo
2020-05-28 14:45 ` [v5] " Markus Elfring
2020-05-28 14:45 ` Markus Elfring
2020-05-28 14:06 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call Dan Carpenter
2020-05-28 14:06 ` 回复: [PATCH v5] workqueue: Remove unnecessary kfree() call in rcu_free_wq() Dan Carpenter
2020-05-28 15:25 ` [v5] " Markus Elfring
2020-05-28 15:25 ` Markus Elfring
2020-05-28 15:02 ` Markus Elfring
2020-05-28 15:02 ` Markus Elfring
2020-05-28 15:02 ` Markus Elfring
2020-05-28 15:02 ` Markus Elfring
2020-05-27 13:52 ` [PATCH v5] " Tejun Heo
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