From: hch@lst.de (Christoph Hellwig)
Subject: [PATCH] nvme/pci: Use host managed power state for suspend
Date: Mon, 13 May 2019 16:57:08 +0200 [thread overview]
Message-ID: <20190513145708.GA25897@lst.de> (raw)
In-Reply-To: <7ab8274ef1ce46fcae54a50abc76ae4a@AUSX13MPC105.AMER.DELL.COM>
On Mon, May 13, 2019@02:54:49PM +0000, Mario.Limonciello@dell.com wrote:
> The Intel DMA controller suspend callbacks in drivers/dma/idma64.c look to me to
> turn off the controller.
How is that relevant? That thing is neither a NVMe controller, nor
even an PCIe device..
> And NVME spec made it sound to me that while in a low power state it shouldn't
> be available if the memory isn't available.
>
> NVME spec in 8.9:
>
> "Host software should request that the controller release the
> assigned ranges prior to a shutdown event, a Runtime D3 event, or any other event
> that requires host software to reclaim the assigned ranges."
The last part of the quoted text is the key - if the assigned range
is reclaimed, that is the memory is going to be used for something else,
we need to release the ranges. But we do not release the ranges,
as we want to keep the memory in use so that we can quickly use it
again.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Mario.Limonciello@dell.com
Cc: kbusch@kernel.org, keith.busch@intel.com, hch@lst.de,
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 16:57:08 +0200 [thread overview]
Message-ID: <20190513145708.GA25897@lst.de> (raw)
In-Reply-To: <7ab8274ef1ce46fcae54a50abc76ae4a@AUSX13MPC105.AMER.DELL.COM>
On Mon, May 13, 2019 at 02:54:49PM +0000, Mario.Limonciello@dell.com wrote:
> The Intel DMA controller suspend callbacks in drivers/dma/idma64.c look to me to
> turn off the controller.
How is that relevant? That thing is neither a NVMe controller, nor
even an PCIe device..
> And NVME spec made it sound to me that while in a low power state it shouldn't
> be available if the memory isn't available.
>
> NVME spec in 8.9:
>
> "Host software should request that the controller release the
> assigned ranges prior to a shutdown event, a Runtime D3 event, or any other event
> that requires host software to reclaim the assigned ranges."
The last part of the quoted text is the key - if the assigned range
is reclaimed, that is the memory is going to be used for something else,
we need to release the ranges. But we do not release the ranges,
as we want to keep the memory in use so that we can quickly use it
again.
next prev parent reply other threads:[~2019-05-13 14:57 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
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 [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190513145708.GA25897@lst.de \
--to=hch@lst.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.