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Date: Fri, 13 Dec 2024 15:38:41 +0100
From: Christoph Hellwig <hch@lst.de>
To: John Garry <john.g.garry@oracle.com>
Cc: brauner@kernel.org, djwong@kernel.org, cem@kernel.org,
	dchinner@redhat.com, hch@lst.de, ritesh.list@gmail.com,
	linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, martin.petersen@oracle.com
Subject: Re: [PATCH v2 0/7] large atomic writes for xfs
Message-ID: <20241213143841.GC16111@lst.de>
References: <20241210125737.786928-1-john.g.garry@oracle.com>
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On Tue, Dec 10, 2024 at 12:57:30PM +0000, John Garry wrote:
> Currently the atomic write unit min and max is fixed at the FS blocksize
> for xfs and ext4.
> 
> This series expands support to allow multiple FS blocks to be written
> atomically.

Can you explain the workload you're interested in a bit more? 

I'm still very scared of expanding use of the large allocation sizes.

IIRC you showed some numbers where increasing the FSB size to something
larger did not look good in your benchmarks, but I'd like to understand
why.  Do you have a link to these numbers just to refresh everyones minds
why that wasn't a good idea.  Did that also include supporting atomic
writes in the sector size <= write size <= FS block size range, which
aren't currently supported, but very useful?