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Date:   Fri, 3 Jan 2020 15:40:22 +0100
From:   David Sterba <dsterba@suse.cz>
To:     Dennis Zhou <dennis@kernel.org>
Cc:     David Sterba <dsterba@suse.com>, Chris Mason <clm@fb.com>,
        Josef Bacik <josef@toxicpanda.com>,
        Omar Sandoval <osandov@osandov.com>, kernel-team@fb.com,
        linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 02/12] btrfs: add bps discard rate limit for async discard
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References: <cover.1577999991.git.dennis@kernel.org>
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On Thu, Jan 02, 2020 at 04:26:36PM -0500, Dennis Zhou wrote:
> +		 */
> +		if (kbps_limit && discard_ctl->prev_discard) {
> +			u64 bps_limit = ((u64)kbps_limit) * SZ_1K;
> +			u64 bps_delay = div64_u64(discard_ctl->prev_discard *
> +						  MSEC_PER_SEC, bps_limit);

I hoped we can get rid of the 64bit division when the kbps is u32 but I
don't think it's necessary, bytes as units of the calculation are fine.

> +
> +			delay = max(delay, msecs_to_jiffies(bps_delay));
> +		}