Am 25.02.2014 14:41, schrieb Kevin Wolf:
> Am 24.02.2014 um 14:01 hat Peter Lieven geschrieben:
>> On 24.02.2014 11:38, Paolo Bonzini wrote:
>>> Il 24/02/2014 11:26, Peter Lieven ha scritto:
I personally do not need this for QCOW2 but for iSCSI. Here the
optimization
is basically sa
Am 24.02.2014 um 14:01 hat Peter Lieven geschrieben:
> On 24.02.2014 11:38, Paolo Bonzini wrote:
> >Il 24/02/2014 11:26, Peter Lieven ha scritto:
> >>
> >>I personally do not need this for QCOW2 but for iSCSI. Here the optimization
> >>is basically saved bandwidth since a zero write becomes a WRITE
On 24.02.2014 11:38, Paolo Bonzini wrote:
Il 24/02/2014 11:26, Peter Lieven ha scritto:
I personally do not need this for QCOW2 but for iSCSI. Here the optimization
is basically saved bandwidth since a zero write becomes a WRITESAME.
It saves bandwidth, but at the potential cost of extra host
Il 24/02/2014 13:07, Kevin Wolf ha scritto:
> Yeah, that's why I wrote "or should be". Those are the intended
> semantics of bdrv_co_write_zeroes without BDRV_REQ_MAY_UNMAP: always
> allocate a cluster that will read as zeroes (allocating even if it
> does not necessarily write the zeroes).
Whi
Am 24.02.2014 um 13:10 hat Paolo Bonzini geschrieben:
> Il 24/02/2014 13:07, Kevin Wolf ha scritto:
> >>> Yeah, that's why I wrote "or should be". Those are the intended
> >>> semantics of bdrv_co_write_zeroes without BDRV_REQ_MAY_UNMAP: always
> >>> allocate a cluster that will read as zeroes (al
On Mon, 02/24 12:51, Paolo Bonzini wrote:
> Il 24/02/2014 12:33, Fam Zheng ha scritto:
> >> This is (or should be) bdrv_co_write_zeroes without BDRV_REQ_MAY_UNMAP.
> >
> >But IIUC bdrv_co_write_zeroes without BDRV_REQ_MAY_UNMAP doesn't require
> >cluster allocation if it's allocated yet, which is a
Am 24.02.2014 um 12:51 hat Paolo Bonzini geschrieben:
> Il 24/02/2014 12:33, Fam Zheng ha scritto:
> >> This is (or should be) bdrv_co_write_zeroes without BDRV_REQ_MAY_UNMAP.
> >
> >But IIUC bdrv_co_write_zeroes without BDRV_REQ_MAY_UNMAP doesn't require
> >cluster allocation if it's allocated yet
Il 24/02/2014 12:33, Fam Zheng ha scritto:
> This is (or should be) bdrv_co_write_zeroes without BDRV_REQ_MAY_UNMAP.
But IIUC bdrv_co_write_zeroes without BDRV_REQ_MAY_UNMAP doesn't require
cluster allocation if it's allocated yet, which is a bit different.
Yeah, that's why I wrote "or should
On 24.02.2014 11:38, Paolo Bonzini wrote:
Il 24/02/2014 11:26, Peter Lieven ha scritto:
I personally do not need this for QCOW2 but for iSCSI. Here the optimization
is basically saved bandwidth since a zero write becomes a WRITESAME.
It saves bandwidth, but at the potential cost of extra host
On Mon, 02/24 11:39, Paolo Bonzini wrote:
> Il 24/02/2014 02:01, Fam Zheng ha scritto:
> >
> >I would do this in qcow2:
> >
> > 1. In qcow2_co_writev, allocate cluster regardless of if data is zero or
> > not.
> > 2. If data is zero, set QCOW2_OFLAG_ZERO in L2.
>
> This is (or should be) bdrv_co_
Il 24/02/2014 02:01, Fam Zheng ha scritto:
I would do this in qcow2:
1. In qcow2_co_writev, allocate cluster regardless of if data is zero or not.
2. If data is zero, set QCOW2_OFLAG_ZERO in L2.
This is (or should be) bdrv_co_write_zeroes without BDRV_REQ_MAY_UNMAP.
Paolo
Il 24/02/2014 11:26, Peter Lieven ha scritto:
I personally do not need this for QCOW2 but for iSCSI. Here the optimization
is basically saved bandwidth since a zero write becomes a WRITESAME.
It saves bandwidth, but at the potential cost of extra host CPU
utilization. I would be fine with ha
On 24.02.2014 11:11, Kevin Wolf wrote:
Am 22.02.2014 um 14:00 hat Peter Lieven geschrieben:
this patch tries to optimize zero write requests
by automatically using bdrv_write_zeroes if it is
supported by the format.
i know that there is a lot of potential for discussion, but i would
like to kno
Am 22.02.2014 um 14:00 hat Peter Lieven geschrieben:
> this patch tries to optimize zero write requests
> by automatically using bdrv_write_zeroes if it is
> supported by the format.
>
> i know that there is a lot of potential for discussion, but i would
> like to know what the others think.
>
>
On Sun, 02/23 20:10, Peter Lieven wrote:
> Am 22.02.2014 17:45, schrieb Fam Zheng:
> > On Sat, 02/22 14:00, Peter Lieven wrote:
> >> this patch tries to optimize zero write requests
> >> by automatically using bdrv_write_zeroes if it is
> >> supported by the format.
> >>
> >> i know that there is a
Am 22.02.2014 17:45, schrieb Fam Zheng:
> On Sat, 02/22 14:00, Peter Lieven wrote:
>> this patch tries to optimize zero write requests
>> by automatically using bdrv_write_zeroes if it is
>> supported by the format.
>>
>> i know that there is a lot of potential for discussion, but i would
>> like t
On Sat, 02/22 14:00, Peter Lieven wrote:
> this patch tries to optimize zero write requests
> by automatically using bdrv_write_zeroes if it is
> supported by the format.
>
> i know that there is a lot of potential for discussion, but i would
> like to know what the others think.
>
> this should
this patch tries to optimize zero write requests
by automatically using bdrv_write_zeroes if it is
supported by the format.
i know that there is a lot of potential for discussion, but i would
like to know what the others think.
this should significantly speed up file system initialization and
sho
18 matches
Mail list logo
