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Date:   Fri, 9 Sep 2022 20:31:30 +0500
From:   Roman Mamedov <rm@romanrm.net>
To:     Jonmichael Hands <jm@chia.net>
Cc:     Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>,
        Logan Gunthorpe <logang@deltatee.com>,
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        Martin Oliveira <Martin.Oliveira@eideticom.com>,
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Subject: Re: [PATCH mdadm v2 1/2] mdadm: Add --discard option for Create
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On Fri, 9 Sep 2022 07:40:00 -0700
Jonmichael Hands <jm@chia.net> wrote:

> Deterministic read zero after TRIM is standardized and can be reported by
> device. If the device supports these bits, they will always return zero
> after discard.

Point is that some/many devices do not report this capability properly, but
actually do read back zeroes after TRIM. Relying on the reporting alone would
exclude a lot of cases where the optimization could have been used. So it is
useful to verify the observed behavior and still allow the optimization in
those cases.

-- 
With respect,
Roman