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From: Tejun Heo <tj@kernel.org>
To: linan666@huaweicloud.com
Cc: josef@toxicpanda.com, axboe@kernel.dk, yukuai3@huawei.com,
	cgroups@vger.kernel.org, linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org, linan122@huawei.com,
	yi.zhang@huawei.com, houtao1@huawei.com, yangerkun@huawei.com
Subject: Re: [PATCH] blk-throttle: Calculate allowed value only when the throttle is enabled
Date: Wed, 4 Oct 2023 09:31:38 -1000	[thread overview]
Message-ID: <ZR29mvoQMxcZcppw@slm.duckdns.org> (raw)
In-Reply-To: <20230928015858.1809934-1-linan666@huaweicloud.com>

Hello,

On Thu, Sep 28, 2023 at 09:58:58AM +0800, linan666@huaweicloud.com wrote:
> From: Li Nan <linan122@huawei.com>
> 
> When the throttle of bps is not enabled, tg_bps_limit() returns U64_MAX,
> which is be used in calculate_bytes_allowed(), and divide 0 error will
> happen.

calculate_bytes_allowed() is just

  return mul_u64_u64_div_u64(bps_limit, (u64)jiffy_elapsed, (u64)HZ); 

The only division is by HZ. How does divide by 0 happen?

Thanks.

-- 
tejun

  reply	other threads:[~2023-10-04 19:31 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-28  1:58 [PATCH] blk-throttle: Calculate allowed value only when the throttle is enabled linan666
2023-10-04 19:31 ` Tejun Heo [this message]
2023-10-04 20:30   ` Khazhy Kumykov
2023-10-04 20:44 ` Khazhy Kumykov
     [not found]   ` <4ace01e8-6815-29d0-70ce-4632818ca701@huaweicloud.com>
2023-10-05 16:24     ` Oleg Nesterov
2023-10-07  1:23       ` Yu Kuai
2023-10-07 15:16         ` Oleg Nesterov
2023-10-08  1:26           ` Yu Kuai
2023-10-08 11:36             ` Oleg Nesterov
2023-10-13 21:51               ` Khazhy Kumykov
2023-10-16  1:46                 ` Yu Kuai
2023-10-16 20:06                   ` Khazhy Kumykov
2023-10-16 21:48                     ` Khazhy Kumykov
2023-10-17  2:38                     ` Yu Kuai
2023-10-05 17:04     ` Oleg Nesterov
2023-10-05 17:15       ` Khazhy Kumykov

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