From: "Paul E. McKenney" <paulmck@kernel.org>
To: Hillf Danton <hdanton@sina.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>,
Oliver Sang <oliver.sang@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Lai Jiangshan <laijs@linux.alibaba.com>,
LKML <linux-kernel@vger.kernel.org>,
lkp@intel.com
Subject: Re: [workqueue] d5bff968ea: WARNING:at_kernel/workqueue.c:#process_one_work
Date: Thu, 28 Jan 2021 10:08:21 -0800 [thread overview]
Message-ID: <20210128180821.GA24510@paulmck-ThinkPad-P72> (raw)
In-Reply-To: <20210128090905.1596-1-hdanton@sina.com>
On Thu, Jan 28, 2021 at 05:09:05PM +0800, Hillf Danton wrote:
> On Thu, 28 Jan 2021 15:52:40 +0800 Xing Zhengjun wrote:
[ . . . ]
> >I test the patch 4 times, no warning appears in the kernel log.
>
> Thank you so much Zhengjun!
>
> And the overall brain dump so far is
>
> 1/ before and after d5bff968ea, changing the allowed ptr at online time
> is the key to quiesce the warning in process_one_work().
>
> 2/ marking pcpu before changing aptr in rebind_workers() is mandatory in
> regards to cutting the risk of triggering such a warning.
>
> 3/ we canot maintain such an order without quiescing the 508 warning for
> kworkers. And we have a couple of excuses to do so, a) the number of
> allowed CPUs is no longer checked in is_per_cpu_kthread() instead of
> PF_NO_SETAFFINITY, b) there is always a followup act to change the aptr
> in order to fix the number of aCPUs.
>
> 4/ same order is maintained also at rescue time.
Just out of curiosity, does this test still fail on current mainline?
Thanx, Paul
next prev parent reply other threads:[~2021-01-28 18:13 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210126073925.1962-1-hdanton@sina.com>
2021-01-27 8:04 ` [workqueue] d5bff968ea: WARNING:at_kernel/workqueue.c:#process_one_work Xing Zhengjun
[not found] ` <20210127092128.2299-1-hdanton@sina.com>
2021-01-28 7:52 ` Xing Zhengjun
[not found] ` <20210128090905.1596-1-hdanton@sina.com>
2021-01-28 18:08 ` Paul E. McKenney [this message]
2021-01-29 6:20 ` Xing Zhengjun
[not found] <20210125092900.1839-1-hdanton@sina.com>
2021-01-26 2:45 ` Xing Zhengjun
2021-01-14 7:45 kernel test robot
[not found] ` <20210114084248.1819-1-hdanton@sina.com>
2021-01-20 13:41 ` Oliver Sang
[not found] ` <20210115072432.150-1-hdanton@sina.com>
2021-01-20 13:46 ` Oliver Sang
[not found] ` <20210121040037.1555-1-hdanton@sina.com>
2021-01-22 1:48 ` Xing Zhengjun
[not found] ` <20210122075903.1722-1-hdanton@sina.com>
2021-01-25 8:37 ` Xing Zhengjun
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