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Subject: Re: block: DMA alignment of IO buffer allocated from slab
To: Christopher Lameter <cl@linux.com>
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From: Jens Axboe <axboe@kernel.dk>
Message-ID: <1a5b255f-682e-783a-7f99-9d02e39c4af2@kernel.dk>
Date: Mon, 24 Sep 2018 12:09:37 -0600
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On 9/24/18 12:00 PM, Christopher Lameter wrote:
> On Mon, 24 Sep 2018, Jens Axboe wrote:
> 
>> The situation is making me a little uncomfortable, though. If we export
>> such a setting, we really should be honoring it...
> 
> Various subsystems create custom slab arrays with their particular
> alignment requirement for these allocations.

Oh yeah, I think the solution is basic enough for XFS, for instance.
They just have to error on the side of being cautious, by going full
sector alignment for memory...

-- 
Jens Axboe