From: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
To: Eric Levy <contact@ericlevy.name>
Cc: "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: "hardware-assisted zeroing"
Date: Tue, 4 Jan 2022 20:33:52 -0500 [thread overview]
Message-ID: <YdT1gEF0zMIN6eQ8@hungrycats.org> (raw)
In-Reply-To: <18d02df50fc7f9c63ff07b5433a445d911538be6.camel@ericlevy.name>
On Tue, Jan 04, 2022 at 08:26:41PM -0500, Eric Levy wrote:
> On Tue, 2022-01-04 at 20:21 -0500, Zygo Blaxell wrote:
>
> > ZNS SSD devices do address mapping entirely in reverse--in a write
> > command, the host says "append this block to zone Z", the drive
> > chooses
> > a block address for the data within that zone, and sends the written
> > block address back to the host filesystem as part of the command
> > reply.
> > This allows the drive to implement writes in parallel (so they are
> > subject to reordering) without having to store where it put user data
> > in the SSD's own memory.
>
> How does the host remember the mapping, and where does it get applied
> during followup access?
That's up to the host filesystem implementation. ZNS devices require
filesystems that speak ZNS protocol. They don't implement a traditional
LBA-oriented interface (or if they do, they provide a separate logical
device interface for that).
next prev parent reply other threads:[~2022-01-05 1:33 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-03 11:08 "hardware-assisted zeroing" Eric Levy
2022-01-03 11:17 ` Qu Wenruo
2022-01-03 11:24 ` Eric Levy
2022-01-03 11:51 ` Qu Wenruo
2022-01-04 10:50 ` Eric Levy
2022-01-04 20:49 ` Zygo Blaxell
2022-01-04 22:37 ` Eric Levy
2022-01-04 22:46 ` Qu Wenruo
2022-01-05 0:38 ` Paul Jones
2022-01-05 0:44 ` Eric Levy
2022-01-05 1:12 ` Paul Jones
2022-01-05 1:20 ` Eric Levy
2022-01-05 1:21 ` Zygo Blaxell
2022-01-05 1:26 ` Eric Levy
2022-01-05 1:33 ` Zygo Blaxell [this message]
2022-01-05 1:37 ` Eric Levy
2022-01-05 2:20 ` Zygo Blaxell
2022-01-05 1:32 ` Zygo Blaxell
2022-01-04 22:37 ` Qu Wenruo
2022-01-03 11:46 ` David Disseldorp
2022-01-03 11:57 ` Qu Wenruo
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