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Sender: Tejun Heo <htejun@gmail.com>
Date:   Mon, 5 Jun 2023 08:04:57 -1000
From:   Tejun Heo <tj@kernel.org>
To:     linan666@huaweicloud.com
Cc:     josef@toxicpanda.com, axboe@kernel.dk, cgroups@vger.kernel.org,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linan122@huawei.com, yukuai3@huawei.com, yi.zhang@huawei.com,
        houtao1@huawei.com, yangerkun@huawei.com
Subject: Re: [PATCH] blk-iocost: use spin_lock_irqsave in
 adjust_inuse_and_calc_cost
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References: <20230527091904.3001833-1-linan666@huaweicloud.com>
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On Sat, May 27, 2023 at 05:19:04PM +0800, linan666@huaweicloud.com wrote:
> From: Li Nan <linan122@huawei.com>
> 
> adjust_inuse_and_calc_cost() use spin_lock_irq() and IRQ will be enabled
> when unlock. DEADLOCK might happen if we have held other locks and disabled
> IRQ before invoking it.
> 
> Fix it by using spin_lock_irqsave() instead, which can keep IRQ state
> consistent with before when unlock.
...
> Fixes: b0853ab4a238 ("blk-iocost: revamp in-period donation snapbacks")
> Signed-off-by: Li Nan <linan122@huawei.com>

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun