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From:   Jens Axboe <axboe@kernel.dk>
To:     tj@kernel.org, josef@toxicpanda.com, chengming.zhou@linux.dev
Cc:     cgroups@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, zhouchengming@bytedance.com
In-Reply-To: <20230720121441.1408522-1-chengming.zhou@linux.dev>
References: <20230720121441.1408522-1-chengming.zhou@linux.dev>
Subject: Re: [PATCH] blk-iocost: skip empty flush bio in iocost
Message-Id: <168988334811.126089.11961578901520630861.b4-ty@kernel.dk>
Date:   Thu, 20 Jul 2023 14:02:28 -0600
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Precedence: bulk


On Thu, 20 Jul 2023 20:14:41 +0800, chengming.zhou@linux.dev wrote:
> The flush bio may have data, may have no data (empty flush), we couldn't
> calculate cost for empty flush bio. So we'd better just skip it for now.
> 
> Another side effect is that empty flush bio's bio_end_sector() is 0, cause
> iocg->cursor reset to 0, may break the cost calculation of other bios.
> 
> This isn't good enough, since flush bio still consume the device bandwidth,
> but flush request is special, can be merged randomly in the flush state
> machine, we don't know how to calculate cost for it for now.
> 
> [...]

Applied, thanks!

[1/1] blk-iocost: skip empty flush bio in iocost
      commit: 013adcbef165c3eaf73e297b7482290593815ab8

Best regards,
-- 
Jens Axboe