From: Jens Axboe <axboe@kernel.dk>
To: Marek Szyprowski <m.szyprowski@samsung.com>,
bh1scw@gmail.com, tj@kernel.org
Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, songmuchun@bytedance.com
Subject: Re: [PATCH] blk-cgroup: Remove unnecessary rcu_read_lock/unlock()
Date: Wed, 18 May 2022 16:29:35 -0600 [thread overview]
Message-ID: <1dad86bb-ae31-5bf8-5810-9e81c68be8ff@kernel.dk> (raw)
In-Reply-To: <46253c48-81cb-0787-20ad-9133afdd9e21@samsung.com>
On 5/18/22 1:28 PM, Marek Szyprowski wrote:
> On 16.05.2022 19:39, bh1scw@gmail.com wrote:
>> From: Fanjun Kong <bh1scw@gmail.com>
>>
>> spin_lock_irq/spin_unlock_irq contains preempt_disable/enable().
>> Which can serve as RCU read-side critical region, so remove
>> rcu_read_lock/unlock().
>>
>> Signed-off-by: Fanjun Kong <bh1scw@gmail.com>
>
> This patch landed in today's linux next-20220518 as commit 77c570a1ea85
> ("blk-cgroup: Remove unnecessary rcu_read_lock/unlock()").
>
> Unfortunately it triggers the following warning on ARM64 based Raspberry
> Pi 4B board:>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 1 at block/blk-cgroup.c:301 blkg_create+0x398/0x4e0
Should this use rcu_read_lock_any_held() rather than rcu_read_lock_held()?
--
Jens Axboe
next prev parent reply other threads:[~2022-05-18 22:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-16 17:39 [PATCH] blk-cgroup: Remove unnecessary rcu_read_lock/unlock() bh1scw
2022-05-16 18:42 ` Tejun Heo
2022-05-17 4:11 ` Muchun Song
2022-05-17 12:13 ` Jens Axboe
[not found] ` <CGME20220518192850eucas1p1458c00d4917c5ed39f2c37c9eb30cd46@eucas1p1.samsung.com>
2022-05-18 19:28 ` Marek Szyprowski
2022-05-18 22:29 ` Jens Axboe [this message]
2022-05-18 22:31 ` Jens Axboe
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