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From: Heiner Litz <hlitz@ucsc.edu>
To: Keith Busch <kbusch@kernel.org>
Cc: "Matias Bjorling" <Matias.Bjorling@wdc.com>,
	"Damien Le Moal" <Damien.LeMoal@wdc.com>,
	"Javier González" <javier@javigon.com>,
	"Matias Bjørling" <mb@lightnvm.io>,
	"Christoph Hellwig" <hch@lst.de>,
	"Keith Busch" <Keith.Busch@wdc.com>,
	"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
	"Sagi Grimberg" <sagi@grimberg.me>,
	"Jens Axboe" <axboe@kernel.dk>,
	"Hans Holmberg" <Hans.Holmberg@wdc.com>,
	"Dmitry Fomichev" <Dmitry.Fomichev@wdc.com>,
	"Ajay Joshi" <Ajay.Joshi@wdc.com>,
	"Aravind Ramesh" <Aravind.Ramesh@wdc.com>,
	"Niklas Cassel" <Niklas.Cassel@wdc.com>,
	"Judy Brock" <judy.brock@samsung.com>
Subject: Re: [PATCH 5/5] nvme: support for zoned namespaces
Date: Fri, 19 Jun 2020 11:17:02 -0700	[thread overview]
Message-ID: <CAJbgVnWru+wRRsJ4KB2DiVPRNfMV39uYNSCi2Y=6d+_GOQO8iw@mail.gmail.com> (raw)
In-Reply-To: <20200619181024.GA1284046@dhcp-10-100-145-180.wdl.wdc.com>

> On Fri, Jun 19, 2020 at 11:08:26AM -0700, Heiner Litz wrote:
> > Hi Matias,
> > no, I am rather saying that the Linux kernel has a deficit or at least
> > is not a good fit for ZNS because it cannot enforce in-order delivery.
>
> FYI, the nvme protocol can't even enforce in-order delivery, so calling
> out linux for this is a moot point.

How does it work in SPDK then? I had understood that SPDK supported
QD>1 for ZNS devices.
I am not saying that Linux is the only problem. The fact remains that
out of order delivery is not a good fit for an interface that requires
sequential writes.

>
> > The requirement of sequential writes basically imposes this
> > requirement. Append essentially a Linux specific fix on the ZNS level
> > and that enforcing ordering would be a cleaner way to enable QD>1.

WARNING: multiple messages have this Message-ID (diff)
From: Heiner Litz <hlitz@ucsc.edu>
To: Keith Busch <kbusch@kernel.org>
Cc: "Jens Axboe" <axboe@kernel.dk>,
	"Niklas Cassel" <Niklas.Cassel@wdc.com>,
	"Damien Le Moal" <Damien.LeMoal@wdc.com>,
	"Ajay Joshi" <Ajay.Joshi@wdc.com>,
	"Sagi Grimberg" <sagi@grimberg.me>,
	"Keith Busch" <Keith.Busch@wdc.com>,
	"Dmitry Fomichev" <Dmitry.Fomichev@wdc.com>,
	"Aravind Ramesh" <Aravind.Ramesh@wdc.com>,
	"Javier González" <javier@javigon.com>,
	"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
	"Hans Holmberg" <Hans.Holmberg@wdc.com>,
	"Matias Bjørling" <mb@lightnvm.io>,
	"Judy Brock" <judy.brock@samsung.com>,
	"Christoph Hellwig" <hch@lst.de>,
	"Matias Bjorling" <Matias.Bjorling@wdc.com>
Subject: Re: [PATCH 5/5] nvme: support for zoned namespaces
Date: Fri, 19 Jun 2020 11:17:02 -0700	[thread overview]
Message-ID: <CAJbgVnWru+wRRsJ4KB2DiVPRNfMV39uYNSCi2Y=6d+_GOQO8iw@mail.gmail.com> (raw)
In-Reply-To: <20200619181024.GA1284046@dhcp-10-100-145-180.wdl.wdc.com>

> On Fri, Jun 19, 2020 at 11:08:26AM -0700, Heiner Litz wrote:
> > Hi Matias,
> > no, I am rather saying that the Linux kernel has a deficit or at least
> > is not a good fit for ZNS because it cannot enforce in-order delivery.
>
> FYI, the nvme protocol can't even enforce in-order delivery, so calling
> out linux for this is a moot point.

How does it work in SPDK then? I had understood that SPDK supported
QD>1 for ZNS devices.
I am not saying that Linux is the only problem. The fact remains that
out of order delivery is not a good fit for an interface that requires
sequential writes.

>
> > The requirement of sequential writes basically imposes this
> > requirement. Append essentially a Linux specific fix on the ZNS level
> > and that enforcing ordering would be a cleaner way to enable QD>1.

_______________________________________________
linux-nvme mailing list
linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme

  reply	other threads:[~2020-06-19 18:17 UTC|newest]

Thread overview: 192+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-15 23:34 [PATCH 0/5] nvme support for zoned namespace command set Keith Busch
2020-06-15 23:34 ` Keith Busch
2020-06-15 23:34 ` [PATCH 1/5] block: add capacity field to zone descriptors Keith Busch
2020-06-15 23:34   ` Keith Busch
2020-06-15 23:49   ` Chaitanya Kulkarni
2020-06-15 23:49     ` Chaitanya Kulkarni
2020-06-16 10:28   ` Javier González
2020-06-16 10:28     ` Javier González
2020-06-16 13:47   ` Daniel Wagner
2020-06-16 13:47     ` Daniel Wagner
2020-06-16 13:54   ` Johannes Thumshirn
2020-06-16 13:54     ` Johannes Thumshirn
2020-06-16 15:41   ` Martin K. Petersen
2020-06-16 15:41     ` Martin K. Petersen
2020-06-15 23:34 ` [PATCH 2/5] null_blk: introduce zone capacity for zoned device Keith Busch
2020-06-15 23:34   ` Keith Busch
2020-06-15 23:46   ` Chaitanya Kulkarni
2020-06-15 23:46     ` Chaitanya Kulkarni
2020-06-16 14:18   ` Daniel Wagner
2020-06-16 14:18     ` Daniel Wagner
2020-06-16 15:48   ` Martin K. Petersen
2020-06-16 15:48     ` Martin K. Petersen
2020-06-15 23:34 ` [PATCH 3/5] nvme: implement I/O Command Sets Command Set support Keith Busch
2020-06-15 23:34   ` Keith Busch
2020-06-16 10:33   ` Javier González
2020-06-16 10:33     ` Javier González
2020-06-16 17:14     ` Niklas Cassel
2020-06-16 17:14       ` Niklas Cassel
2020-06-16 15:58   ` Martin K. Petersen
2020-06-16 15:58     ` Martin K. Petersen
2020-06-16 17:01     ` Keith Busch
2020-06-16 17:01       ` Keith Busch
2020-06-17  9:50       ` Niklas Cassel
2020-06-17  9:50         ` Niklas Cassel
2020-06-16 17:06     ` Niklas Cassel
2020-06-16 17:06       ` Niklas Cassel
2020-06-17  2:01       ` Martin K. Petersen
2020-06-17  2:01         ` Martin K. Petersen
2020-06-15 23:34 ` [PATCH 4/5] nvme: support for multi-command set effects Keith Busch
2020-06-15 23:34   ` Keith Busch
2020-06-16 10:34   ` Javier González
2020-06-16 10:34     ` Javier González
2020-06-16 16:03   ` Martin K. Petersen
2020-06-16 16:03     ` Martin K. Petersen
2020-06-15 23:34 ` [PATCH 5/5] nvme: support for zoned namespaces Keith Busch
2020-06-15 23:34   ` Keith Busch
2020-06-16 10:41   ` Javier González
2020-06-16 10:41     ` Javier González
2020-06-16 11:18     ` Matias Bjørling
2020-06-16 11:18       ` Matias Bjørling
2020-06-16 12:00       ` Javier González
2020-06-16 12:00         ` Javier González
2020-06-16 12:06         ` Matias Bjørling
2020-06-16 12:06           ` Matias Bjørling
2020-06-16 12:24           ` Javier González
2020-06-16 12:24             ` Javier González
2020-06-16 12:27             ` Matias Bjørling
2020-06-16 12:27               ` Matias Bjørling
2020-06-16 12:35             ` Damien Le Moal
2020-06-16 12:35               ` Damien Le Moal
     [not found]               ` <CGME20200616130815uscas1p1be34e5fceaa548eac31fb30790a689d4@uscas1p1.samsung.com>
2020-06-16 13:08                 ` Judy Brock
2020-06-16 13:08                   ` Judy Brock
2020-06-16 13:32                   ` Matias Bjørling
2020-06-16 13:32                     ` Matias Bjørling
2020-06-16 13:34                   ` Damien Le Moal
2020-06-16 13:34                     ` Damien Le Moal
2020-06-16 14:16               ` Javier González
2020-06-16 14:16                 ` Javier González
2020-06-16 14:42                 ` Damien Le Moal
2020-06-16 14:42                   ` Damien Le Moal
2020-06-16 15:02                   ` Javier González
2020-06-16 15:02                     ` Javier González
2020-06-16 15:20                     ` Matias Bjørling
2020-06-16 15:20                       ` Matias Bjørling
2020-06-16 16:03                       ` Javier González
2020-06-16 16:03                         ` Javier González
2020-06-16 16:07                         ` Matias Bjorling
2020-06-16 16:07                           ` Matias Bjorling
2020-06-16 16:21                           ` Javier González
2020-06-16 16:21                             ` Javier González
2020-06-16 16:25                             ` Matias Bjørling
2020-06-16 16:25                               ` Matias Bjørling
2020-06-16 15:48                     ` Keith Busch
2020-06-16 15:48                       ` Keith Busch
2020-06-16 15:55                       ` Javier González
2020-06-16 15:55                         ` Javier González
2020-06-16 16:04                         ` Matias Bjorling
2020-06-16 16:04                           ` Matias Bjorling
2020-06-16 16:07                         ` Keith Busch
2020-06-16 16:07                           ` Keith Busch
2020-06-16 16:13                           ` Javier González
2020-06-16 16:13                             ` Javier González
2020-06-17  0:38                             ` Damien Le Moal
2020-06-17  0:38                               ` Damien Le Moal
2020-06-17  6:18                               ` Javier González
2020-06-17  6:18                                 ` Javier González
2020-06-17  6:54                                 ` Damien Le Moal
2020-06-17  6:54                                   ` Damien Le Moal
2020-06-17  7:11                                   ` Javier González
2020-06-17  7:11                                     ` Javier González
2020-06-17  7:29                                     ` Damien Le Moal
2020-06-17  7:29                                       ` Damien Le Moal
2020-06-17  7:34                                       ` Javier González
2020-06-17  7:34                                         ` Javier González
2020-06-17  0:14                     ` Damien Le Moal
2020-06-17  0:14                       ` Damien Le Moal
2020-06-17  6:09                       ` Javier González
2020-06-17  6:09                         ` Javier González
2020-06-17  6:47                         ` Damien Le Moal
2020-06-17  6:47                           ` Damien Le Moal
2020-06-17  7:02                           ` Javier González
2020-06-17  7:02                             ` Javier González
2020-06-17  7:24                             ` Damien Le Moal
2020-06-17  7:24                               ` Damien Le Moal
2020-06-17  7:29                               ` Javier González
2020-06-17  7:29                                 ` Javier González
     [not found]         ` <CGME20200616123503uscas1p22ce22054a1b4152a20437b5abdd55119@uscas1p2.samsung.com>
2020-06-16 12:35           ` Judy Brock
2020-06-16 12:35             ` Judy Brock
2020-06-16 12:37             ` Damien Le Moal
2020-06-16 12:37               ` Damien Le Moal
2020-06-16 12:37             ` Matias Bjørling
2020-06-16 12:37               ` Matias Bjørling
2020-06-16 13:12               ` Judy Brock
2020-06-16 13:12                 ` Judy Brock
2020-06-16 13:18                 ` Judy Brock
2020-06-16 13:18                   ` Judy Brock
2020-06-16 13:32                   ` Judy Brock
2020-06-16 13:32                     ` Judy Brock
2020-06-16 13:39                     ` Damien Le Moal
2020-06-16 13:39                       ` Damien Le Moal
2020-06-17  7:43     ` Christoph Hellwig
2020-06-17  7:43       ` Christoph Hellwig
2020-06-17 12:01       ` Martin K. Petersen
2020-06-17 12:01         ` Martin K. Petersen
2020-06-17 15:00         ` Javier González
2020-06-17 15:00           ` Javier González
2020-06-17 14:42       ` Javier González
2020-06-17 14:42         ` Javier González
2020-06-17 17:57         ` Matias Bjørling
2020-06-17 17:57           ` Matias Bjørling
2020-06-17 18:28           ` Javier González
2020-06-17 18:28             ` Javier González
2020-06-17 18:55             ` Matias Bjorling
2020-06-17 18:55               ` Matias Bjorling
2020-06-17 19:09               ` Javier González
2020-06-17 19:09                 ` Javier González
2020-06-17 19:23                 ` Matias Bjørling
2020-06-17 19:23                   ` Matias Bjørling
2020-06-17 19:40                   ` Javier González
2020-06-17 19:40                     ` Javier González
2020-06-17 23:44                     ` Heiner Litz
2020-06-17 23:44                       ` Heiner Litz
2020-06-18  1:55                       ` Keith Busch
2020-06-18  1:55                         ` Keith Busch
2020-06-18  4:24                         ` Heiner Litz
2020-06-18  4:24                           ` Heiner Litz
2020-06-18  5:15                           ` Damien Le Moal
2020-06-18  5:15                             ` Damien Le Moal
2020-06-18 20:47                             ` Heiner Litz
2020-06-18 20:47                               ` Heiner Litz
2020-06-18 21:04                               ` Matias Bjorling
2020-06-18 21:04                                 ` Matias Bjorling
2020-06-18 21:19                               ` Keith Busch
2020-06-18 21:19                                 ` Keith Busch
2020-06-18 22:05                                 ` Heiner Litz
2020-06-18 22:05                                   ` Heiner Litz
2020-06-19  0:57                                   ` Damien Le Moal
2020-06-19  0:57                                     ` Damien Le Moal
2020-06-19 10:29                                   ` Matias Bjorling
2020-06-19 10:29                                     ` Matias Bjorling
2020-06-19 18:08                                     ` Heiner Litz
2020-06-19 18:08                                       ` Heiner Litz
2020-06-19 18:10                                       ` Keith Busch
2020-06-19 18:10                                         ` Keith Busch
2020-06-19 18:17                                         ` Heiner Litz [this message]
2020-06-19 18:17                                           ` Heiner Litz
2020-06-19 18:22                                           ` Keith Busch
2020-06-19 18:22                                             ` Keith Busch
2020-06-19 18:25                                           ` Matias Bjørling
2020-06-19 18:25                                             ` Matias Bjørling
2020-06-19 18:40                                             ` Heiner Litz
2020-06-19 18:40                                               ` Heiner Litz
2020-06-19 18:18                                       ` Matias Bjørling
2020-06-19 18:18                                         ` Matias Bjørling
2020-06-20  6:33                                       ` Christoph Hellwig
2020-06-20  6:33                                         ` Christoph Hellwig
2020-06-20 17:52                                         ` Heiner Litz
2020-06-20 17:52                                           ` Heiner Litz
2020-06-22 14:01                                           ` Christoph Hellwig
2022-03-02 21:11                   ` Luis Chamberlain
2020-06-17  2:08   ` Martin K. Petersen
2020-06-17  2:08     ` Martin K. Petersen

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