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Subject: Re: [PATCH RFC v2 8/8] blk-mq-tag: allow shared queue/hctx to get
 more driver tags
To:     Bart Van Assche <bvanassche@acm.org>,
        Yu Kuai <yukuai1@huaweicloud.com>, hch@lst.de,
        kbusch@kernel.org, ming.lei@redhat.com, axboe@kernel.dk
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        yi.zhang@huawei.com, yangerkun@huawei.com,
        "yukuai (C)" <yukuai3@huawei.com>
References: <20231021154806.4019417-1-yukuai1@huaweicloud.com>
 <20231021154806.4019417-9-yukuai1@huaweicloud.com>
 <d8b5db3c-cd0a-4e88-ae08-e17b97bdfc55@acm.org>
From:   Yu Kuai <yukuai1@huaweicloud.com>
Message-ID: <c8fb8f4e-2982-0fce-e226-7fe9be91e211@huaweicloud.com>
Date:   Tue, 24 Oct 2023 09:07:47 +0800
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Hi,

在 2023/10/24 4:46, Bart Van Assche 写道:
> On 10/21/23 08:48, Yu Kuai wrote:
>> +    if (!busy) {
>> +        ctl->timer_running = false;
>> +    } else {
>> +        ctl->timer.expires = jiffies + HZ;
>> +        add_timer(&ctl->timer);
>> +    }
>> +    spin_unlock_irq(&tags->lock);
> 
> [ ... ]
> 
>> +inc_busy:
>> +    atomic_inc(&info->busy_count);
>> +    if (!tags->ctl.timer_running &&
>> +        try_cmpxchg_relaxed(&tags->ctl.timer_running, &timer_running, 
>> true)) {
>> +        tags->ctl.timer.expires = jiffies + HZ;
>> +        add_timer(&tags->ctl.timer);
>> +    }
>>   }
> 
> So the choice has been made to let the timer expire after one second? I
> think the choice of the timer value is important enough to mention it in
> the patch description.

Yes, I agree, I admit that I was not that cautious while choose 1 HZ in
this version, I'm not quite sure is this approch will be accepted yet,
while this is the best(simple and workable) way that I can think of.

Thanks,
Kuai

> 
> Thanks,
> 
> Bart.
> 
> 
> .
>