From: keith.busch@intel.com (Keith Busch)
Subject: [PATCH rfc] nvme-pci: make sure to flush sqe writes before db record update
Date: Thu, 8 Mar 2018 11:42:20 -0700 [thread overview]
Message-ID: <20180308184220.GA6163@localhost.localdomain> (raw)
In-Reply-To: <20180308183623.GE6785@ziepe.ca>
On Thu, Mar 08, 2018@11:36:23AM -0700, Jason Gunthorpe wrote:
> On Thu, Mar 08, 2018@07:56:37PM +0200, Sagi Grimberg wrote:
> > If the SQE and DB update have been reordered,
>
> But that can't happen, the SQE is written before
> nvme_dbbuf_update_and_check_event(), and that function does wmb.
I believe Sagi is talking about the typical controller that doesn't
have shadow db registers (no real nvme device has those), which doesn't
currently go through a path calling wmb().
next prev parent reply other threads:[~2018-03-08 18:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-07 17:56 [PATCH rfc] nvme-pci: make sure to flush sqe writes before db record update Sagi Grimberg
2018-03-08 7:56 ` Christoph Hellwig
2018-03-08 15:51 ` Keith Busch
2018-03-08 17:20 ` Jason Gunthorpe
2018-03-08 17:37 ` Keith Busch
2018-03-08 17:56 ` Sagi Grimberg
2018-03-08 18:36 ` Jason Gunthorpe
2018-03-08 18:42 ` Keith Busch [this message]
2018-05-30 23:34 ` Sagi Grimberg
2018-05-31 5:47 ` Christoph Hellwig
2018-05-31 7:53 ` Sagi Grimberg
2018-05-31 15:20 ` Jason Gunthorpe
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