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Sender: Tejun Heo <htejun@gmail.com>
Date:   Thu, 19 Jan 2023 16:00:12 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Li Lingfeng <lilingfeng3@huawei.com>
Cc:     linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
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Subject: Re: [PATCH-next v3] lib: parser: optimize match_NUMER apis to use
 local array
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On Fri, Jan 20, 2023 at 10:13:04AM +0800, Li Lingfeng wrote:
> Memory will be allocated to store substring_t in match_strdup(), which means
> the caller of match_strdup() may need to be scheduled out to wait for reclaiming
> memory.
> 
> Using local array to store substring_t to remove the restriction.
> 
> Link: https://lore.kernel.org/all/20221104023938.2346986-5-yukuai1@huaweicloud.com/
> Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>

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

This fixes a sleep-while-atomic splat in blk-iocost, so it'd be a good idea to add:

 Fixes: 2c0647988433 ("blk-iocost: don't release 'ioc->lock' while updating params").

The mm tree likely is the best fit but given the splat the block tree can
work too. Andrew, Jens, what do you think?

Thanks.

-- 
tejun