Il 21/02/2013 16:25, Dietmar Maurer ha scritto:
>>> I just posted v5 of the patch. But I get a slow down of 15% if I use
>>> bdrv_is_allocated_above. (tested with empty qcow2 files.)
>>
>> Strange, for an unallocated area bdrv_is_allocated_above and bdrv_read really
>> do the same thing apart from
> > I just posted v5 of the patch. But I get a slow down of 15% if I use
> > bdrv_is_allocated_above. (tested with empty qcow2 files.)
>
> Strange, for an unallocated area bdrv_is_allocated_above and bdrv_read really
> do the same thing apart from writing the zeroes to the buffer.
> The code looks
- Messaggio originale -
> Da: "Dietmar Maurer"
> A: "Paolo Bonzini"
> Cc: qemu-devel@nongnu.org
> Inviato: Giovedì, 21 febbraio 2013 12:40:52
> Oggetto: RE: [PATCH v3 2/6] add basic backup support to block driver
>
> > > > I think you do. You're wasting time reading unallocated
> > >
> > > I think you do. You're wasting time reading unallocated clusters
> > > and checking that they are zero. bdrv_is_allocated_above gives you
> > > the same information much more efficiently.
> >
> > I thought that just returns information if the data is allocated, or
> > if data is on backing
> > >> This should call bdrv_is_allocated_above like the other block jobs do.
> > >> It would be needed later anyway to backup only the topmost image.
> > >
> > > I do not need that information now, so why do you want that I add dead
> code?
> >
> > I think you do. You're wasting time reading unal
> >> This should call bdrv_is_allocated_above like the other block jobs do.
> >> It would be needed later anyway to backup only the topmost image.
> >
> > I do not need that information now, so why do you want that I add dead code?
>
> I think you do. You're wasting time reading unallocated clust
Il 21/02/2013 07:33, Dietmar Maurer ha scritto:
>> This should call bdrv_is_allocated_above like the other block jobs do.
>> It would be needed later anyway to backup only the topmost image.
>
> I do not need that information now, so why do you want that I add dead code?
I think you do. You're w
> This should call bdrv_is_allocated_above like the other block jobs do.
> It would be needed later anyway to backup only the topmost image.
I do not need that information now, so why do you want that I add dead code?
Il 19/02/2013 12:31, Dietmar Maurer ha scritto:
> +start = 0;
> +end = (bs->total_sectors + BACKUP_BLOCKS_PER_CLUSTER - 1) /
> +BACKUP_BLOCKS_PER_CLUSTER;
> +
> +DPRINTF("backup_run start %s %zd %zd\n", bdrv_get_device_name(bs),
> +start, end);
> +
> +int ret = 0
On 02/19/2013 04:31 AM, Dietmar Maurer wrote:
> Function backup_job_create() creates a block job to backup a block device.
> The coroutine is started with backup_job_start().
>
> We call backup_do_cow() for each write during backup. That function
> reads the original data and pass it to backup_dum
Function backup_job_create() creates a block job to backup a block device.
The coroutine is started with backup_job_start().
We call backup_do_cow() for each write during backup. That function
reads the original data and pass it to backup_dump_cb().
The tracked_request infrastructure is used to s
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