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Subject: Re: [PATCH] sbitmap: fix possible io hung due to lost wakeup
To:     Jan Kara <jack@suse.cz>, Keith Busch <kbusch@kernel.org>
Cc:     Yu Kuai <yukuai1@huaweicloud.com>, axboe@kernel.dk, osandov@fb.com,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        yi.zhang@huawei.com, "yukuai (C)" <yukuai3@huawei.com>
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From:   Yu Kuai <yukuai1@huaweicloud.com>
Message-ID: <dcb95c47-6e68-6ec0-a74d-317a905d0a1b@huaweicloud.com>
Date:   Thu, 8 Sep 2022 17:45:11 +0800
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Hi, Jan

?? 2022/09/08 17:33, Jan Kara д??:
> On Wed 07-09-22 12:20:09, Keith Busch wrote:
>> On Wed, Sep 07, 2022 at 06:41:50PM +0200, Jan Kara wrote:
>>> On Wed 07-09-22 08:13:40, Keith Busch wrote:
>>>>
>>>> I'm not sure about this part. We've already decremented, so the freed bit is
>>>> accounted for against the batch. Returning true here may double-count the freed
>>>> bit, right?
>>>
>>> Yes, we may wake up waiters unnecessarily frequently. But that's a
>>> performance issue at worst and only if it happens frequently. So I don't
>>> think it matters in practice (famous last words ;).
>>
>> Ok, let's go with that. Do you want to send the patch? I have a follow-up fix
>> for batched tagging that depends on this.
> 
> I think Kuai will do that. But if not, I can certainly take his patch and
> resubmit it with the fixup.

Sorry that I'm too busy with work stuff recently, I can do that in a few
weeks. In the meantime, feel free go on without me.

Thanks,
Kuai
> 
> 								Honza
>