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Date:   Thu, 27 Apr 2023 17:01:04 -0600
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Subject: Re: [PATCH] nvmet: Reorder fields in 'struct nvmet_ns'
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To:     Chaitanya Kulkarni <chaitanyak@nvidia.com>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Sagi Grimberg <sagi@grimberg.me>,
        Christoph Hellwig <hch@lst.de>,
        "kernel-janitors@vger.kernel.org" <kernel-janitors@vger.kernel.org>,
        "linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>
References: <aea924d31f2bd2f740b1ccc6f462905bd6cab763.1682624855.git.christophe.jaillet@wanadoo.fr>
 <ba5df67e-534d-6f79-6277-80c755ca7e94@nvidia.com>
From:   Jens Axboe <axboe@kernel.dk>
In-Reply-To: <ba5df67e-534d-6f79-6277-80c755ca7e94@nvidia.com>
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On 4/27/23 4:59?PM, Chaitanya Kulkarni wrote:
> On 4/27/23 12:47, Christophe JAILLET wrote:
>> Group some variables based on their sizes to reduce holes.
>> On x86_64, this shrinks the size of 'struct nvmet_ns' from 520 to 512
>> bytes.
>>
> 
> Although this looks good, we at least need to document what
> happens on other arch(s) which are not mentioned in the
> commit log ? is there a possibility that someone might come
> up with the contradictory data in future for the arch(s) which
> arch that are not mentioned here ?

The change is certainly not going to make things _worse_ for any arch,
so I think that's somewhat of a pointless exercise and an unreasonable
ask for something that makes sense on 64-bit arm/x86 and saves half the
space.

-- 
Jens Axboe