From: hch@lst.de (Christoph Hellwig)
Subject: [PATCH] nvme/pci: Use host managed power state for suspend
Date: Mon, 13 May 2019 16:54:15 +0200 [thread overview]
Message-ID: <20190513145415.GA25774@lst.de> (raw)
In-Reply-To: <b12ff66f8c224e4199ff1b90ed6bc393@AUSX13MPC105.AMER.DELL.COM>
On Mon, May 13, 2019@02:43:43PM +0000, Mario.Limonciello@dell.com wrote:
> Well I've got a thought, quoting the NVME spec:
> "After a successful completion of a Set Features command for this feature, the controller shall be in the
> Power State specified. If enabled, autonomous power state transitions continue to occur from the new state."
>
> If APST is enabled on this disk, what is to stop an autonomous reverse
> transition from queue activity on the way down?
Nothing. But once the system is suspending we should not see I/O.
If we see I/O the queue freezing in the original patch Kai Heng and the
previous one from Keith is probably required, although I suspect it
just papers over problems higher up in the queue. If we don't see I/O
the device is just behaving oddly.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Mario.Limonciello@dell.com
Cc: hch@lst.de, keith.busch@intel.com, sagi@grimberg.me,
linux-nvme@lists.infradead.org, rafael@kernel.org,
linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
kai.heng.feng@canonical.com
Subject: Re: [PATCH] nvme/pci: Use host managed power state for suspend
Date: Mon, 13 May 2019 16:54:15 +0200 [thread overview]
Message-ID: <20190513145415.GA25774@lst.de> (raw)
In-Reply-To: <b12ff66f8c224e4199ff1b90ed6bc393@AUSX13MPC105.AMER.DELL.COM>
On Mon, May 13, 2019 at 02:43:43PM +0000, Mario.Limonciello@dell.com wrote:
> Well I've got a thought, quoting the NVME spec:
> "After a successful completion of a Set Features command for this feature, the controller shall be in the
> Power State specified. If enabled, autonomous power state transitions continue to occur from the new state."
>
> If APST is enabled on this disk, what is to stop an autonomous reverse
> transition from queue activity on the way down?
Nothing. But once the system is suspending we should not see I/O.
If we see I/O the queue freezing in the original patch Kai Heng and the
previous one from Keith is probably required, although I suspect it
just papers over problems higher up in the queue. If we don't see I/O
the device is just behaving oddly.
next prev parent reply other threads:[~2019-05-13 14:54 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-10 21:29 [PATCH] nvme/pci: Use host managed power state for suspend Keith Busch
2019-05-10 21:29 ` Keith Busch
2019-05-11 0:52 ` Mario.Limonciello
2019-05-11 0:52 ` Mario.Limonciello
2019-05-11 0:52 ` Mario.Limonciello
2019-05-13 14:24 ` Mario.Limonciello
2019-05-13 14:24 ` Mario.Limonciello
2019-05-13 14:24 ` Mario.Limonciello
2019-05-13 14:37 ` Christoph Hellwig
2019-05-13 14:37 ` Christoph Hellwig
2019-05-13 14:43 ` Mario.Limonciello
2019-05-13 14:43 ` Mario.Limonciello
2019-05-13 14:43 ` Mario.Limonciello
2019-05-13 14:54 ` Christoph Hellwig [this message]
2019-05-13 14:54 ` Christoph Hellwig
2019-05-13 14:55 ` Keith Busch
2019-05-13 14:55 ` Keith Busch
2019-05-13 15:05 ` Mario.Limonciello
2019-05-13 15:05 ` Mario.Limonciello
2019-05-13 15:05 ` Mario.Limonciello
2019-05-13 15:04 ` Keith Busch
2019-05-13 15:04 ` Keith Busch
2019-05-14 8:04 ` Rafael J. Wysocki
2019-05-14 8:04 ` Rafael J. Wysocki
2019-05-14 22:16 ` Keith Busch
2019-05-14 22:16 ` Keith Busch
2019-05-15 9:00 ` Rafael J. Wysocki
2019-05-15 9:00 ` Rafael J. Wysocki
2019-05-13 14:37 ` Keith Busch
2019-05-13 14:37 ` Keith Busch
2019-05-13 14:54 ` Mario.Limonciello
2019-05-13 14:54 ` Mario.Limonciello
2019-05-13 14:54 ` Mario.Limonciello
2019-05-13 14:57 ` Christoph Hellwig
2019-05-13 14:57 ` Christoph Hellwig
2019-05-13 15:16 ` Keith Busch
2019-05-13 15:16 ` Keith Busch
2019-05-13 17:16 ` Kai-Heng Feng
2019-05-13 17:16 ` Kai-Heng Feng
2019-05-13 18:16 ` Keith Busch
2019-05-13 18:16 ` Keith Busch
2019-05-13 18:01 ` Mario.Limonciello
2019-05-13 18:01 ` Mario.Limonciello
2019-05-13 18:01 ` Mario.Limonciello
2019-05-14 6:11 ` Christoph Hellwig
2019-05-14 6:11 ` Christoph Hellwig
2019-05-11 1:33 ` Edmund Nadolski
2019-05-11 1:33 ` Edmund Nadolski
2019-05-11 7:22 ` Christoph Hellwig
2019-05-11 7:22 ` Christoph Hellwig
2019-05-12 14:34 ` Sagi Grimberg
2019-05-12 14:34 ` Sagi Grimberg
2019-05-13 13:36 ` Keith Busch
2019-05-13 13:36 ` Keith Busch
2019-05-12 6:06 ` Chaitanya Kulkarni
2019-05-12 6:06 ` Chaitanya Kulkarni
2019-05-12 14:30 ` Minwoo Im
2019-05-12 14:30 ` Minwoo Im
2019-05-12 15:20 ` Chaitanya Kulkarni
2019-05-12 15:20 ` Chaitanya Kulkarni
2019-05-13 13:47 ` Keith Busch
2019-05-13 13:47 ` Keith Busch
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