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Subject: Re: [PATCH v9] bio: limit bio max size
To:     Changheun Lee <nanich.lee@samsung.com>, axboe@kernel.dk,
        yi.zhang@redhat.com, ming.lei@redhat.com, bgoncalv@redhat.com,
        hch@lst.de, jaegeuk@kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, patchwork-bot@kernel.org
References: <CGME20210503101008epcas1p25d6b727dafcf9ff24db6aa41a3f611fa@epcas1p2.samsung.com>
 <20210503095203.29076-1-nanich.lee@samsung.com>
From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <f2529eb0-b388-9ecd-f74e-7bf004902c9c@acm.org>
Date:   Mon, 3 May 2021 09:33:19 -0700
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On 5/3/21 2:52 AM, Changheun Lee wrote:
> bio size can grow up to 4GB when muli-page bvec is enabled.
> but sometimes it would lead to inefficient behaviors.
> in case of large chunk direct I/O, - 32MB chunk read in user space -
> all pages for 32MB would be merged to a bio structure if the pages
> physical addresses are contiguous. it makes some delay to submit
> until merge complete. bio max size should be limited to a proper size.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>