Il 28/06/2013 18:17, Alex Bligh ha scritto:
>
> But as Stefano says:
>
> --On 28 June 2013 11:56:29 +0100 Stefano Stabellini
> wrote:
>
>> This is PV only, at least for the moment: emulated disks always use
>> writeback caching.
>> From the performance point of view, making this change for IDE
--On 28 June 2013 11:44:41 +0100 Ian Jackson
wrote:
Looks useful. Are you planning to do this for both emulated and pv
disks?
Emulated disks don't have the same problem because they don't try to
use O_DIRECT on pages shared with the guest via the Xen grant table
mechanism.
I should have
On Fri, 28 Jun 2013, Paolo Bonzini wrote:
> Il 27/06/2013 20:16, Stefano Stabellini ha scritto:
> > Support backend option "direct-io-safe". This is documented as
> > follows in the Xen backend specification:
> >
> > * direct-io-safe
> > * Values: 0/1 (boolean)
> > * Default
On Fri, 28 Jun 2013, Alex Bligh wrote:
> Stefano,
>
> --On 27 June 2013 19:16:30 +0100 Stefano Stabellini
> wrote:
>
> > * Therefore this option gives the backend permission to use
> > * O_DIRECT, notwithstanding that bug.
>
> Looks useful. Are you planning to do this for both emula
Paolo Bonzini writes ("Re: [PATCH v2] xen_disk: support "direct-io-safe"
backend option"):
> Il 27/06/2013 20:16, Stefano Stabellini ha scritto:
> > The original proposal for a "cache" backend option has been dropped
> > because it was believed too wide, especially considering that at the
> > mome
Alex Bligh writes ("Re: [Qemu-devel] [PATCH v2] xen_disk: support
"direct-io-safe" backend option"):
> Stefano,
> --On 27 June 2013 19:16:30 +0100 Stefano Stabellini
> wrote:
>
> > * Therefore this option gives the backend permission to use
>
Stefano,
--On 27 June 2013 19:16:30 +0100 Stefano Stabellini
wrote:
* Therefore this option gives the backend permission to use
* O_DIRECT, notwithstanding that bug.
Looks useful. Are you planning to do this for both emulated and pv
disks?
--
Alex Bligh
Il 27/06/2013 20:16, Stefano Stabellini ha scritto:
> Support backend option "direct-io-safe". This is documented as
> follows in the Xen backend specification:
>
> * direct-io-safe
> * Values: 0/1 (boolean)
> * Default Value: 0
> *
> * The underlying storage is not a
Support backend option "direct-io-safe". This is documented as
follows in the Xen backend specification:
* direct-io-safe
* Values: 0/1 (boolean)
* Default Value: 0
*
* The underlying storage is not affected by the direct IO memory
* lifetime bug. See:
*
