From: Keith Busch <kbusch@kernel.org>
To: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: "Mario.Limonciello@dell.com" <Mario.Limonciello@dell.com>,
"hch@lst.de" <hch@lst.de>, "axboe@fb.com" <axboe@fb.com>,
"sagi@grimberg.me" <sagi@grimberg.me>,
"rafael@kernel.org" <rafael@kernel.org>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
"Wysocki, Rafael J" <rafael.j.wysocki@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
"Busch, Keith" <keith.busch@intel.com>
Subject: Re: [PATCH] nvme-pci: Use non-operational power state instead of D3 on Suspend-to-Idle
Date: Fri, 10 May 2019 08:02:09 -0600 [thread overview]
Message-ID: <20190510140209.GG9675@localhost.localdomain> (raw)
In-Reply-To: <BC5EB1D0-8718-48B3-ACAB-F7E5571D821D@canonical.com>
On Thu, May 09, 2019 at 11:05:42PM -0700, Kai-Heng Feng wrote:
> Yes, that’ what I was told by the NVMe vendor, so all I know is to impose a
> memory barrier.
> If mb() shouldn’t be used here, what’s the correct variant to use in this
> context?
I'm afraid the requirement is still not clear to me. AFAIK, all our
barriers routines ensure data is visible either between CPUs, or between
CPU and devices. The CPU never accesses HMB memory, so there must be some
other reasoning if this barrier is a real requirement for this device.
next prev parent reply other threads:[~2019-05-10 14:07 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-08 18:59 [PATCH] nvme-pci: Use non-operational power state instead of D3 on Suspend-to-Idle Kai-Heng Feng
2019-05-08 19:15 ` Chaitanya Kulkarni
2019-05-08 19:16 ` Keith Busch
2019-05-08 19:30 ` Kai-Heng Feng
2019-05-08 19:38 ` Mario.Limonciello
2019-05-08 19:51 ` Christoph Hellwig
2019-05-08 20:28 ` Mario.Limonciello
2019-05-09 6:12 ` Christoph Hellwig
2019-05-09 6:48 ` Kai-Heng Feng
2019-05-09 6:52 ` Christoph Hellwig
2019-05-09 9:19 ` Rafael J. Wysocki
2019-05-09 9:25 ` Christoph Hellwig
2019-05-09 20:48 ` Rafael J. Wysocki
2019-05-09 9:07 ` Rafael J. Wysocki
2019-05-09 9:42 ` Kai-Heng Feng
2019-05-09 9:56 ` Christoph Hellwig
2019-05-09 10:28 ` Kai-Heng Feng
2019-05-09 10:31 ` Christoph Hellwig
2019-05-09 11:59 ` Kai-Heng Feng
2019-05-09 18:57 ` Mario.Limonciello
2019-05-09 19:28 ` Keith Busch
2019-05-09 20:54 ` Rafael J. Wysocki
2019-05-09 21:16 ` Keith Busch
2019-05-09 21:39 ` Rafael J. Wysocki
2019-05-09 21:37 ` Mario.Limonciello
2019-05-09 21:54 ` Keith Busch
2019-05-09 22:19 ` Mario.Limonciello
2019-05-10 6:05 ` Kai-Heng Feng
2019-05-10 8:23 ` Rafael J. Wysocki
2019-05-10 13:52 ` Keith Busch
2019-05-10 15:15 ` Kai Heng Feng
2019-05-10 15:36 ` Keith Busch
2019-05-10 14:02 ` Keith Busch [this message]
2019-05-10 15:18 ` Kai Heng Feng
2019-05-10 15:49 ` hch
2019-05-10 5:30 ` Christoph Hellwig
2019-05-10 13:51 ` Keith Busch
2019-05-09 16:20 ` Keith Busch
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