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Date:   Mon, 13 May 2019 09:04:58 -0600
From:   Keith Busch <kbusch@kernel.org>
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
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On Mon, May 13, 2019 at 03:05:42PM +0000, Mario.Limonciello@dell.com wrote:
> This system power state - suspend to idle is going to freeze threads.
> But we're talking a multi threaded kernel.  Can't there be a timing problem going
> on then too?  With a disk flush being active in one task and the other task trying
> to put the disk into the deepest power state.  If you don't freeze the queues how
> can you guarantee that didn't happen?

But if an active data flush task is running, then we're not idle and
shouldn't go to low power.