From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Ric Wheeler <rwheeler@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Ric Wheeler <ricwheeler@gmail.com>,
"Black, David" <david.black@emc.com>,
Jeremy Linton <jlinton@tributary.com>,
Hannes Reinecke <hare@suse.de>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"Martin K. Petersen" <mkp@mkp.net>,
Jeff Moyer <jmoyer@redhat.com>, Tejun Heo <tj@kernel.org>,
Mike Snitzer <snitzer@redhat.com>,
"Elliott, Robert (Server Storage)" <Elliott@hp.com>,
"Knight, Frederick" <Frederick.Knight@netapp.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>
Subject: Re: T10 WCE interpretation in Linux & device level access
Date: Thu, 25 Apr 2013 07:12:37 -0700 [thread overview]
Message-ID: <1366899157.2232.1.camel@dabdike> (raw)
In-Reply-To: <517914FA.4040106@redhat.com>
On Thu, 2013-04-25 at 07:35 -0400, Ric Wheeler wrote:
> It was pointed out to me that RCD is "Read Cache Disable" so by
> setting it to
> zero, we are enabling the read cache (not that we ever look at this
> bit or send
> it down). The WCE bit is "write cache enable" so the polarity of the
> bits is
> inverted.
>
> Should be fine regardless :)
Just look at the code. We already do the right thing.
The whole reason for combining both into cache policy is that half the
world got the individual bits wrong. We translate from an
understandable cache policy to and from WCE/RCD speak.
James
next prev parent reply other threads:[~2013-04-25 14:12 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-23 19:41 T10 WCE interpretation in Linux & device level access Ric Wheeler
2013-04-23 20:07 ` James Bottomley
2013-04-23 22:39 ` Jeremy Linton
2013-04-24 5:44 ` Elliott, Robert (Server Storage)
2013-04-24 11:00 ` Ric Wheeler
2013-04-27 16:09 ` James Bottomley
2013-04-24 11:17 ` Paolo Bonzini
2013-04-24 12:07 ` Hannes Reinecke
2013-04-24 12:08 ` Paolo Bonzini
2013-04-24 12:12 ` Hannes Reinecke
2013-04-24 12:23 ` Paolo Bonzini
2013-04-24 12:27 ` Mike Snitzer
2013-04-24 12:27 ` Ric Wheeler
2013-04-24 12:57 ` Paolo Bonzini
2013-04-24 14:35 ` Jeremy Linton
2013-04-24 18:20 ` Black, David
2013-04-24 20:41 ` Ric Wheeler
2013-04-24 21:02 ` James Bottomley
2013-04-24 21:54 ` Paolo Bonzini
2013-04-24 22:09 ` James Bottomley
2013-04-24 22:36 ` Ric Wheeler
2013-04-24 22:46 ` James Bottomley
2013-04-25 11:35 ` Ric Wheeler
2013-04-25 14:12 ` James Bottomley [this message]
2013-04-25 1:32 ` Martin K. Petersen
2013-04-27 6:03 ` Paolo Bonzini
2013-04-24 11:30 ` Hannes Reinecke
2013-04-23 20:28 ` Douglas Gilbert
2013-04-24 15:40 ` Douglas Gilbert
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