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Date:   Fri, 10 Jul 2020 14:09:12 +0100
From:   Christoph Hellwig <hch@infradead.org>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     Kanchan Joshi <joshiiitr@gmail.com>,
        Christoph Hellwig <hch@infradead.org>,
        Kanchan Joshi <joshi.k@samsung.com>, viro@zeniv.linux.org.uk,
        bcrl@kvack.org, Damien.LeMoal@wdc.com, asml.silence@gmail.com,
        linux-fsdevel@vger.kernel.org, Matias Bj??rling <mb@lightnvm.io>,
        linux-kernel@vger.kernel.org, linux-aio@kvack.org,
        io-uring@vger.kernel.org, linux-block@vger.kernel.org,
        Selvakumar S <selvakuma.s1@samsung.com>,
        Nitesh Shetty <nj.shetty@samsung.com>,
        Javier Gonzalez <javier.gonz@samsung.com>
Subject: Re: [PATCH v3 4/4] io_uring: add support for zone-append
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On Thu, Jul 09, 2020 at 12:50:27PM -0600, Jens Axboe wrote:
> It might, if you have IRQ context for the completion. task_work isn't
> expensive, however. It's not like a thread offload.
> 
> > Using flags have not been liked here, but given the upheaval involved so
> > far I have begun to feel - it was keeping things simple. Should it be
> > reconsidered?
> 
> It's definitely worth considering, especially since we can use cflags
> like Pavel suggested upfront and not need any extra storage. But it
> brings us back to the 32-bit vs 64-bit discussion, and then using blocks
> instead of bytes. Which isn't exactly super pretty.

block doesn't work for the case of writes to files that don't have
to be aligned in any way.  And that I think is the more broadly
applicable use case than zone append on block devices.